|
Speaker
|
Albuquerque
Ivone
|
|
Institution
|
University
of Sao Paulo
|
|
Title
|
Signals for
Universal Extra
Dimensions in Neutrino
|
|
Abstract
|
Interaction of high energy neutrinos within the Earth will
produce KK particles predicted in Universal Extra Dimension
models. We will show that these will have a clear signature
and detectable rate in km3 neutrino telescopes.
|
|
Speaker
|
Aoi
Junichi
|
|
Institution
|
Yukawa
Institute for
Theoretical Physics
|
|
Title
|
The effect of energy
amplification variance on the shock acceleration
|
|
Abstract
|
We compare two methods to calculate the power-law index of
the shock acceleration changing the velocity of the shock
from the non-relativistic one to the highly-relativistic
one. Two methods are developed by Peacock (1981) and Vietri
(2003), and Blasi & Vietri (2005) indicated these two
methods give different results. We examine this difference
in detail and show the reason why two methods give the
different results. We consider four cases for the
scattering: large-angle scattering both in the upstream
and the down stream (model A), deflection by large-scale
magnetic fields in the upstream and large-angle scattering
in the downstream (model B), small-angle scattering in
both the upstream and the downstream (model C) and
deflection by large-scale magnetic field in the upstream
and small-angle scattering in the downstream (model D). We
show the power-law index decreases as the shock velocity
becomes fast in model A. The difference between the
Peacock's method and Vietri's one becomes biggest in the
mildly-relativistic shock regime and disappears in the
highly-relativistic shock regime. The power-law index
converges as the shock velocity becomes fast in model B.
The difference derived from the two methods also
converges. We conclude the difference of the two methods
is due to the variance of the energy gain factor's
distribution.
|
|
Speaker
|
Bass Steven
|
|
Institution
|
Innsbruck
|
|
Title
|
Electroweak baryogenesis and “topological condensates”
|
|
Abstract
|
Electroweak vacuum transition processes (sphalerons) in
the early Universe provide a possible explanation of the
baryon asymmetry. Combining this physics with the
anomalous commutators of Adler and Boulware and
renormalization group invariance, we argue that
electroweak baryon number violation also induces a
``topological condensate'' in the vacuum, which (probably)
survives in the Universe we live in today.
The derivation of this effect involves issues of how one
should include non-local topological structure in local
anomalous Ward identities. Here we discuss the physics
of this effect together with its possible phenomenology.
|
|
Speaker
|
Belov Konstantin
|
|
Institution
|
Rutgers University
|
|
Title
|
Proton-air Cross Section at
1018.5 eV
|
|
Abstract
|
We used the High Resolution Fly's Eye cosmic ray detector
data to measure the proton-air inelastic cross-section at
1018.5 eV. A deconvolution measurement technique allowed us
to reduce the interaction model dependence and increase the
stability of the result. We present the result and discuss
the systematic uncertainty which includes the uncertainty
from unknown mass composition of the cosmic rays at
ultra-high energies. A prediction for the LHC cross-section
measurement is also discussed.
|
|
Speaker
|
Berge David
|
|
Institution
|
CERN
|
|
Title
|
Very-High-Energy Gamma-Ray
Observations of
Galactic
|
|
Abstract
|
Shell-type supernova remnants are the prime source
candidates for the acceleration of Galactic Cosmic Rays at
least up to the knee region. However, experimental proof is
difficult due to propagation effects of charged particles in
the magnetic fields of the interstellar medium. The most
promising way of proving the existence of high-energy
particles in supernova shells is the detection of
very-high-energy (E > 100 GeV) gamma rays produced in
interactions of high-energetic cosmic rays with ambient
material close to their acceleration sites.
|
|
Speaker
|
Bertucci Bruna
|
|
Institution
|
Perugia University and INFN
Perugia
|
|
Title
|
Dark Matter searches with
AMS-02
|
|
Abstract
|
The Alpha Magnetic Spectrometer (AMS), to be installed on
the International Space Station, will provide data on
cosmic radiations in a large range of rigidity from 0.5 GV
up to 2 TV. The main physics goals in the astroparticle
domain are the anti- matter and the dark matter searches.
Observations and cosmology indicate that the Universe may
include a large amount of unknown Dark Matter. It should
be composed of non baryonic Weakly Interacting Massive
Particles (WIMP). A good WIMP candidate being the lightest
SUSY particle in R-parity conserving models. AMS offers a
unique opportunity to study simultaneously SUSY dark
matter in three decay channels from the neutralino
annihilation: e+, antiproton and gamma. The expected flux
sensitivities in 3 year exposure for the e+/e- ratio,
antiproton, antideuterons and gamma yields as a function
of energy are presented and compared to other indirect
searches.
|
|
Speaker
|
Blum Kfir
|
|
Institution
|
Weizmann Institute of Science,
Israel
|
|
Title
|
Probing CP violation in
neutrino oscillations
with neutrino telescope
|
|
Abstract
|
Measurements of flavor ratios of astrophysical neutrino
fluxes are sensitive to the two yet un-
known mixing parameters \theta_{13} and \delta through the
combination \sin\theta_{13}\cos\delta. We extend previous
studies by considering the possibility that neutrino
fluxes from more than a single type of sources
will be measured. We point out that, if reactor
experiments establish a lower bound on \theta_{13}, then
neutrino telescopes might establish an upper bound on
|\cos\delta| that is smaller than one, and by that
prove that CP is violated in neutrino oscillations. Such a
measurement requires several favorable
ingredients to occur: (i) \theta_{13} is not far below the
present upper bound; (ii) The uncertainties in
\theta_{12} and \theta_{23} are reduced by a factor of
about two; (iii) Neutrino fluxes from muon-damped sources
are identified, and their flavor ratios measured with
accuracy of order 10% or better. For the last
condition to be achieved with the planned km3 detectors,
the neutrino flux should be close to the
Waxman-Bahcall bound. It motivates neutrino telescopes
that are effectively about 10 times larger
than IceCube for energies of O(100 TeV), even at the
expense of a higher energy threshold.
|
|
Speaker
|
Boyarsky Alexey
|
|
Institution
|
CERN
|
|
Title
|
Searching for
sterile neutrino DM
|
|
Abstract
|
The extension of the SM by 3 right-handed ("sterile")
neutrinos allows to explain a number of phenomena in particle physics,
astrophysics and cosmology, including baryon asymmetry of the Universe and
neutrino oscillations. The lightest of these neutrinos is a viable DM candidate,
which can be either cold or warm. I will review the properties of this candidate
and discuss the existing restrictions on its parameters as well as prospects for
future direct and indirect searches. From the point of view of astrophysical
searches, it is important that this DM candidate a) is a decaying rather then
annihilating particle, which makes it much less sensitive to the details of DM
distributions b) should be searched in X-rays, not only in gamma-rays.
|
|
Speaker
|
Bringmann
Torsten
|
|
Institution
|
SISSA
|
|
Title
|
Gamma-ray spectra
from dark
matter annihilations
|
|
Abstract
|
Being able to safely distinguish astrophysical from
potential DM annihilation signals is of utmost importance in
indirect dark matter searches. To this end, one almost
unavoidably needs distinctive -- and unique -- spectral
signatures to look for. In this talk, I point out that
internal bremsstrahlung, photons radiated off charged
annihilation products, provide such a signature. In fact,
they often even dominate the expected gamma-ray spectrum
from dark matter annihilations and should thus in any case
be accounted for. It is, in particular, demonstrated that
this is not only true for special situations, such as dark
matter candidates with TeV-scale masses or large branching
ratios into light leptons, but for a large part of the
parameter space of neutralino dark matter in the MSSM.
Finally, I comment on the potential of using these
signatures to gain further insight into the nature of the
dark matter.
|
|
Speaker
|
Brion
Elisabeth
|
|
Institution
|
CEA-Saclay
|
|
Title
|
A detailed
morphology of the W 28
region at TeV energies as revealed by H.E.S.S.
|
|
Abstract
|
It is believed that supernova remnants (SNR) can be an
acceleration site for cosmic rays, which may give rise to
observable high-energy gamma-ray emission via neutral pion
decay from p-p interactions. This emission mechanism could
be further enhanced if the SNR shell interacts with a close
by dense molecular cloud, as seems to occur in the W 28 SNR
region. Therefore, the four H.E.S.S. telescopes were pointed
in the W 28 direction during ~42 hr between 2004 and 2006.
The data were analysed using the so-called 2-dimensional
model, which revealed a complex morphology consisting of
several resolved sources at gamma-ray energies > 0.2 TeV.
One such compact source is located at the north-eastern
boundary of the W 28 SNR where the presence of several OH
masers testify for the interaction of the SNR shell with a
dense molecular cloud. This source otherwise seems
associated with (90 cm) radio and X-ray features. At ~0.5°
south of the SNR shell, a wide gamma-ray excess zone is
resolved into three distinct emission spots, one of which is
coincident with a new SNR candidate found in a recent 90 cm
radio survey. The other sources could be linked to either
local molecular clouds or compact HII regions, such as W
28A2. The detailed morphology of the W 28 region as seen
with TeV gamma-rays will be presented and possible
counterparts for the different emission spots will [...]
|
|
Speaker
|
Budnik
Ran
|
|
Institution
|
Weizmann Institute
|
|
Title
|
Cosmic rays from
trans-relativistic supernovae
|
|
Abstract
|
We derive constraints which must be satisfied by the sources
of 1015 to 1018 eV cosmic rays, under the assumption that the
sources are Galactic. We show that while these constraints are
not satisfied by ordinary supernovae, which are believed to be
the sources of <1015 eV cosmic rays, they may be satisfied
by the recently discovered class of trans-relativistic
supernovae (TRSNe), supernovae associated with subenergetic
gamma-ray bursts. A crucial TRSN characteristic, which
distinguishes them from ordinary supernovae and allows them to
satisfy the derived constraints, is the deposition
of a significant fraction, > 10-2, of the explosion energy
in mildly relativistic, \Gamma\beta > 1, ejecta. Galactic TRSNe
may therefore be the sources of cosmic rays with
energies up to 1018 eV.
|
|
Speaker
|
Carrigan
Svenja
|
|
Institution
|
MPIK, Heidelberg,
Germany
|
|
Title
|
Establishing a
connection between
high-power pulsars
and
very-high-energy gamma-ray
sources
|
|
Abstract
|
Recently, advances in VHE instrumentation have made the
discovery of many new, predominantly Galactic, sources
possible. Of these, a significant number can be identified
as pulsar wind nebulae. It has long been known that pulsars
can drive powerful winds of highly relativistic particles.
These winds end in a termination shock from which
high-energy particles with a wide spectrum of energies
emerge. High-energy electrons and positrons among these
particles give rise to two components of electromagnetic
radiation: a low-energy component from synchrotron radiation
and a high-energy component from inverse Compton
upscattering of ambient photons. Details of the energy
conversion mechanisms in the vicinity of pulsars are not
well understood, nor is it known if all pulsars drive pulsar
wind nebulae and emit high-energy radiation. Here we show
that for a sample of pulsars in the central Milky Way,
pulsars with large spin-down energy flux are with high
probability associated with VHE gamma-ray sources. This
implies that these pulsars emit on the order of 1% of their
spin-down energy in tera electron volt gamma-ray energies.
|
|
Speaker
|
Cerdeno
David G.
|
|
Institution
|
Universidad
Autonoma de Madrid
|
|
Title
|
Identifying WIMPs
through the
simultaneous measurements of their axial and scalar
couplings
|
|
Abstract
|
The potential identification of WIMP dark matter candidates
in direct detection experiments which are simultaneously
sensitive to both spin-dependent and spin-independent
couplings is investigated. The particular cases of the
neutralino in supersymmetric theories and Kaluza-Klein dark
matter in models with universal extra dimensions are studied
through the determination of the theoretical predictions for
their axial and scalar couplings. A case study is done for
the COUPP experiment (Chicagoland Observatory for
Underground Particle Physics), whose projected sensitivity
could allow the exploration of a part of the parameter space
of both WIMP candidates. Furthermore, the possibility of
employing different detection liquids provides a
significantly more precise determination of the WIMP axial
and scalar couplings. This possibly allows the
discrimination between neutralino and Kaluza-Klein dark
matter.
|
|
Speaker
|
Colafrancesco
Sergio
|
|
Institution
|
ASI-ASDC and INAF
|
|
Title
|
Direct probes of
DM through radio
and microwave
|
|
Abstract
|
We discuss the multifrequency DM annihilation signals and we
focus in particular on the ability of radio and microwave
experiments to provide stringent and direct probes of the
nature of DM matter.
|
|
Speaker
|
Cirelli
Marco
|
|
Institution
|
SphT – CEA/Saclay
|
|
Title
|
Minimal Dark
Matter
|
|
Abstract
|
I present a simple model of Dark Matter in terms of a WIMP that has gauge
interactions only (a property that assures automatically the stability of the
particle, for suitable choices of quantum numbers) and discuss its
phenomenology and astrophysical signatures.
|
|
Speaker
|
Cuoco
Alessandro
|
|
Institution
|
Institute for
Physics and
Astronomy, University of Aarhus
|
|
Title
|
The Signature of
Large Scale
Structure on the Very High Energy Gamma-Ray Sky
|
|
Abstract
|
If the diffuse extragalactic gamma ray emission traces the
large scale structures of the universe, peculiar anisotropy
patterns are expected in the gamma ray sky. In particular, because of
the cutoff distance introduced by the absorption of 0.1-10 TeV
photons on the infrared/optical background, prominent correlations
with the local structures within a range of few hundreds Mpc
should be present. We provide detailed predictions of the signal
based on the PSCz map of the local universe. We also use mock N-body
catalogues complemented with the halo model of structures to study
some statistical features of the expected signatures. The results
are largely independent from cosmological details, and depend
mostly on the index of correlation (or bias) of the sources with
respect to the large scale distribution of galaxies. For instance,
the predicted signal in the case of a quadratic correlation (as it
may happen for a dark matter annihilation contribution to the
diffuse gamma flux) differs substantially from a linear
correlation case, providing a complementary tool to unveil the
nature of the sources of the diffuse gamma ray emission. The
chances of the present and future space and ground based
observatories to measure these features are discussed.
|
|
Speaker
|
De
Mitri Ivan
|
|
Institution
|
Università del
salento and INFN,
Lecce
|
|
Title
|
First results
from the ARGO-YBJ
experiment
|
|
Abstract
|
Very high energy gamma ray astronomy and cosmic ray physics
are among the main scientific goals of the ARGO-YBJ
experiment. The detector, which is located in Tibet (China)
at 4300 m a.s.l., is a full coverage Extensive Air Shower
array consisting of a carpet of Resistive Plate Chambers
(RPC) of about 7000 m2. The high altitude and the full
coverage ensure a very low energy threshold (few hundreds of
GeV for primary photons), while the detector time resolution
(sigma_t ≈1ns) gives a good pointing accuracy, thus allowing
a high sensitivity to gamma-ray sources, with a field of
view of more than 2 sr and a duty cycle close to hundred
percent.
The detector layout, performance and location, offer a
unique possibility to make a detailed study of several
properties of the hadronic component of the cosmic ray flux
in the 1-1000 TeV primary energy range. In particular, the
topological structure of the shower, the lateral
distribution, the energy spectrum and the space and time
flux modulations can be measured with high sensitivity.
Moreover, the use of a full coverage detector with a high
space granularity gives detailed images of the shower front,
that can be used to test different hypotheses on the cosmic
ray interaction model, the shower development in the
atmosphere, and particle physics at very high energies.
|
|
Speaker
|
Donato
Fiorenza
|
|
Institution
|
University of
Torino
|
|
Title
|
Dark Matter in
Cosmic Ray
|
|
Abstract
|
I discuss the antimatter cosmic fluxes produced by
supersymmetric dark matter annihilation in the Galactic halo.
Propagation properties for charged particles originating in
the halo will be treated. I will also how the present/next
generation of instruments will be able to disentangle an exotic
contribution against the astrophysical background of antiprotons,
antideuterons and positrons, thus unraveling the presence of a
particle dark halo in the Milky Way.
|
|
Speaker
|
Das
Santabrata
|
|
Institution
|
ARCSEC, Sejong
University, South
Korea
|
|
Title
|
Propagation of
UHE protons
through a magnetized
large scale
structure
|
|
Abstract
|
The propagation of UHECRs is affected by the intergalactic
magnetic fields that were produced during the course of the
large scale structure formation of the universe. We adopt a
novel model where the large scale extragalactic magnetic
fields (EGMF) are estimated from local dynamic properties of
the gas flows in hydrodynamic simulations of a concordance
$\Lambda$CDM universe. With the model magnetic fields, we
calculate the deflection angle, time delay and energy
spectrum of protons with $E > 10^{19}$ eV that are injected
at cosmological sources and then travel through the large
scale structure of the universe, losing the energy due to
interactions with the cosmic background radiation.
Implications of this study on the origin of UHECRs are
discussed.
|
|
Speaker
|
Descamps
Freija
|
|
Institution
|
University of
Ghent
|
|
Title
|
Feasibility study
for acoustic
neutrino detection in ice:
the South Pole
Acoustic Test
Setup.
|
|
Abstract
|
The target volume needed for detection of the predicted
small cosmogenic neutrino flux is a few orders of magnitude
larger than the instrumented volumes of the Cherenkov
neutrino telescopes currently under construction. Combining
this optical technique with new instrumentation that is
sensitive to the radio and acoustic signatures of an UHE
neutrino interaction would allow for a larger sensitive
volume at reasonable cost. The South Pole Acoustic Test
Setup (SPATS) has been built to evaluate the acoustic
characteristics of the Antarctic ice in the 10 to 100 kHz
frequency range so that the feasibility and specific design
of an acoustic neutrino detection array at South Pole can be
evaluated. SPATS consists of three vertical strings that
have been deployed in the upper 400 meter of the Antarctic
ice cap in January 2007, using the upper part of IceCube
holes. Each of them has 7 stages, consisting of one
transmitter and one sensor module. An overview of the SPATS
detector and first results will be presented.
|
|
Speaker
|
Diemand
Juerg
|
|
Institution
|
UCSC
|
|
Title
|
Evolution of Dark
Matter
Structures
|
|
Abstract
|
Supercomputer simulations now allow to follow the formation and evolution of
CDM halos and some of their subhalos. I will discuss recent results from the "Via
Lactea" run: It samples a Milky Way scale halo with over 200 million particles
and resolves over 10'000 subhalos and sub-subhalos. The mass in substructure
has still not converged, i.e. it is growing with better numerical resolution. This
wealth of structure has implications for direct and indirect dark matter
detection, stellar streams, disk heating, gravitational lensing and for
comparisons to the Local Group dwarf galaxy population.
|
|
Speaker
|
Dobler
Gregory
|
|
Institution
|
Harvard University
|
|
Title
|
The WMAP Haze
Excess and WIMP
Annihilations
|
|
Abstract
|
The WMAP "haze" is an extended region of excess microwaves towards the
Galactic Center relative to known ISM emissions. I will first present the results of
our analysis of the morphological and spectral features of the haze. From there,
I will show that they are consistent with synchrotron emission from an injection
of high energy electrons/positrons sourced by ~500 GeV neutralino DM
annihilations with thermal relic cross section in the galactic DM halo with a
rho~r-1.2 density profile and no boost factor. Halo annihilations of this type
have significant consequences for present and future indirect observations such
as PAMELA and GLAST.
|
|
Speaker
|
Ergin
Tulun
|
|
Institution
|
University of
Massachusetts, USA
|
|
Title
|
TeV Gamma-ray
Astronomy with the
VERITAS Array
|
|
Abstract
|
The Very Energetic Radiation Imaging Telescope Array System
(VERITAS) is an array of four imaging atmospheric Cherenkov
telescopes designed for gamma-ray astronomy above 100 GeV.
VERITAS is located at the Whipple Observatory at Mt. Hopkins
in southern Arizona, USA, and the first telescope has been
operating since the beginning of 2005. Observations in full
array mode started in April 2007. The recent status on
initial observations and results from data recorded from
several different potential gamma-ray sources will be presented.
|
|
Speaker
|
Fargion Daniele
|
|
Institution
|
Physics Department, Rome Univ.
1, La Sapienza
|
|
Title
|
Neutrino and SUSY signals by
airshowering
beyond the edge
|
|
Abstract
|
The UHECR must contain both GZK neutrino component as well
as PeV energy Antineutrino electron signals. They might
interact in air and produce air-showers at atmosphere edges.
Also UHE neutralino and Gluinos might induce such inclined
airshowers. Finally UHE neutrino tau may skim the Earth and
lead to up-ward Tau Air-showers beyond the Earth edge.
These events might be present in TeV telescope records by
different signatures: Splitting Cherenkov lights,
Correlation between UHECR and gamma active sources, delayed
air-showering clustered along Gamma TeV-GeV sources. We
enlist the novel way to see the sky at horizons and the
surprising imprint of rising UHE Neutrino and UHE SUSY
Astronomy.
|
|
Speaker
|
Finkbeiner Douglas
|
|
Institution
|
Harvard-Smithsonian Center for
Astrophysics
|
|
Title
|
Observable consequences of
eXciting Dark
Matter (XDM)
|
|
Abstract
|
I will discuss the astrophysical implications of the "Exciting Dark
Matter" theory (XDM; Finkbeiner & Weiner 2007). XDM refers to a class
of theories in which a WIMP has an internal degree of freedom that can
be excited by collisions, and de-excites by emitting an e+e-
pair (via an intermediate virtual boson). The net result is that WIMP
kinetic energy is converted into pairs. There are multiple possible
realizations of this scenario, but all have similar astrophysical
consequences: (i) a substantial e+e- signal in the center of the
Galaxy (as observed by CGRO/OSSE and Integral/SPI) and in other
galaxies and clusters, (ii) heating the inner tens of kpc of
galaxy clusters -- possibly enough to balance X-ray cooling, and (iii)
enhanced BH accretion in the most massive clusters at early
times.Because XDM WIMPs do not couple directly to e+e-, but rather
couple via a (~1-1000 MeV) intermediate boson, XDM annihilation is
then also expected to result in a hard e+e-/neutrino spectrum, and the
(unusually hard) indirect synchrotron and gamma-rays from those e+e-
interacting with the interstellar medium.
|
|
Speaker
|
Filippini Jeffrey
|
|
Institution
|
University of California -
Berkeley
|
|
Title
|
Status and prospects of the
Cryogenic Dark
Matter Search
|
|
Abstract
|
The Cryogenic Dark Matter Search (CDMS) seeks to detect the
interactions of dark matter WIMPs using simultaneous
measurements of ionization and athermal phonons in
semiconductor detectors. Based on a run of 74.5 live days
with 12 detectors at the Soudan Underground Laboratory, CDMS
has excluded spin-independent WIMP-nucleon cross sections
greater than 1.6e-43 cm2 for a 60 GeV/c2 WIMP within the
standard halo model. The collaboration had been running its
full complement of 30 detectors at Soudan since October 2006
and is in the process of analyzing its first run in this
configuration. The collaboration is also engaged in the
development of SuperCDMS, an extension of our technology to
larger detector masses which will be very complementary to
searches for new physics at the LHC. I will outline the
current status and future directions of the CDMS experiment.
|
|
Speaker
|
Fairbairn Malcolm
|
|
Institution
|
CERN
|
|
Title
|
The HR diagram of WIMP burning
stars
|
|
Abstract
|
I will present work detailing the effects upon stellar
evolution of WIMP accretion onto stars. In particular I will
focus on the change in the HR diagram of stars in regions of
high WIMP density and how it can constrain the density and
properties of dark matter.
|
|
Speaker
|
Fairbairn Malcolm
|
|
Institution
|
CERN
|
|
Title
|
Stable massive particles at
colliders
|
|
Abstract
|
I will review the zoo of stable massive particles which
might be produced at the LHC and their possible implications
for cosmology and astrophysics.
|
|
Speaker
|
Feinstein Fabrice
|
|
Institution
|
LPTA / Université Montpellier
II/IN2P3/CNRS
|
|
Title
|
H.E.S.S. phase II
|
|
Abstract
|
H.E.S.S. in its phase I is the most sensitive gamma ray
Cherenkov telescope currently operating with a 100 GeV
threshold. The construction of the H.E.S.S. phase II
telescope has started in 2006. First light is foreseen in
2009. Its 28 m diameter mirror will allow observations down
to 20 GeV, giving a useful overlap with the GLAST satellite
sensitive range. In the steroscopic mode with the four 13 m
diameter mirrors of phase I, the sensitivity will be
increased by a factor 2 and the angular resolution improved,
while the threshold will be 50 GeV.
I will review the design, the status of construction and the
expected performances of HESS II.
|
|
Speaker
|
Green Anne
|
|
Institution
|
University of Nottingham
|
|
Title
|
Dark matter substructure
|
|
Abstract
|
WIMP direct and indirect detection signals both depend on the dark
matter distribution on sub-galactic scales. I will discuss the
microphysics of WIMPs in the early Universe and the properties of the
first, smallest WIMP microhalos to form. I will then overview the
dynamical processes which these microhalos are subject to, the
current state of our understanding of these processes and the
implications for experiments.
|
|
Speaker
|
Gabici Stefano
|
|
Institution
|
MPIK - Heidelberg
|
|
Title
|
Searching for galactic cosmic
ray pevatrons
with
multi-TeV gamma rays and
neutrinos
|
|
Abstract
|
We discuss the possibility of observing ultra high energy
cosmic ray sources in high energy gamma rays. Protons
propagating away from their accelerators produce secondary
electrons during interactions with cosmic microwave
background photons. These electrons start an electromagnetic
cascade that results in a broad band gamma ray emission. We
show that in a magnetized Universe
(B > 10-12 G) such emission is likely to be too extended to
be detected above the diffuse background. A more promising
possibility comes from the detection of synchrotron photons
from the extremely energetic secondary electrons. Although
this emission is produced in a rather extended region of
size ~ 10Mpc, it is expected to be point-like and detectable
at GeV energies if the intergalactic magnetic field is at
the nanogauss level.
|
|
Speaker
|
Gilmore Rudy
|
|
Institution
|
University of California,
santa Cruz
|
|
Title
|
The Extragalactic Background
Light and
Absorption
in Gamma Ray Spectra
|
|
Abstract
|
Recent state-of-the-art semi-analytic models (SAMs) can now
accurately model the history of galaxy formation and
evolution. These SAMs utilize a 'forward evolution'
approach and include all of the important processes for
determining photon emission from galaxies, such as cooling
and shock heating of gas, galaxy mergers, star formation and
aging, supernova and AGN feedback, and the reprocessing of
light by dust. I will be presenting our group's latest
prediction of the extra-galactic background light based on
this work and will discuss the implications for the
attenuation of VHE gamma rays from distant sources due to
pair-production. These results will be compared to recent
limits placed on the EBL by observations of TeV blazar
spectra by experiments such as H.E.S.S. The implications
for reconstructing the intrinsic spectra of distant TeV
blazars will be addressed. Additionally, by including in
this model estimates of far-UV emission from quasars and
star-forming galaxies, as determined by the latest
constraints on ionizing flux, I will discuss the prospects
for detecting attenuation in the spectrum of high-redshift
gamma-ray sources by the upcoming GLAST experiment.
|
|
Speaker
|
Giocoli Carlo
|
|
Institution
|
University of Padova
|
|
Title
|
Hierarchical formation of the
Milky Way with micro-solar mass resolution
|
|
Abstract
|
In the hierarchical picture the dark matter halos grow as
consequence of repeated merging events.
The satellites that merge with the main branch of the
merging-history-tree of a present-day halo, can survive as
substructures. According to the extended-Press & Schechter
theory, I will discuss how to built up a merger-tree of a
Milky Way-size dark matter halo with micro solar mass
resolution. Will be also discussed the gamma-ray emission
from this population.
|
|
Speaker
|
Goodman Jordan
|
|
Institution
|
University of Maryland,
College Park
|
|
Title
|
HAWC – A Wide Field TeV
Observatory
|
|
Abstract
|
The HAWC (High Altitude Water Cherenkov) observatory is a
next generation EAS detector based upon technology that was
developed and proven with the Milagro detector. HAWC will
have ~15 times the sensitivity of Milagro while retaining a
~2sr field of view and ~95% duty cycle. When completed, HAWC
will be sensitive to gamma-ray induced air showers from 100
GeV to 100 TeV with a median energy around 1 TeV. After two
years of operation HAWC will have surveyed the entire of the
northern sky with a sensitivity below 35mCrab and will be
able to see transient signals of 1 Crab at 5σ in a single
day. HAWC will have unprecedented sensitivity to diffuse
sources and the capability to map out diffuse emission in
the galaxy. In this talk, the design, performance and
capabilities of the HAWC observatory will be discussed.
|
|
Speaker
|
Guetta Dafne
|
|
Institution
|
OAR – Osservatorio di Roma
|
|
Title
|
High energy emission from internal shocks in Gamma Ray Bursts
|
|
Abstract
|
In this talk I will give some prediction of the high energy
emission that can be produced in the internal shock scenario
and the possibility that this will be detected by present
and future detectors like AGILE and GLAST.
Internal shocks may be responsible both of the prompt
emission and of the flares superimposed on the afterglow
X-ray lightcurves.
The detection of this high energy (GeV) emission will allow
to disentangle between different models.
|
|
Speaker
|
Hambye Thomas
|
|
Institution
|
Service de Physique Theorique
|
|
Title
|
TeV effects of neutrino seasaw model
|
|
Abstract
|
In the context of the 3 basic seesaw neutrino mass models, we present a
systematic study of possible processes induced at low scale (renormalization of
the Standard Model parameter effects, rare leptonic decays, W and Z decays,etc).
We determine under which conditions such processes could be large enough to
be observable in a near future.
|
|
Speaker
|
Hill Gary
|
|
Institution
|
University of Wisconsin, Madison
|
|
Title
|
Diffuse high-energy neutrino searches in AMANDA-II
and IceCube: results and future prospects
|
|
Abstract
|
With the analysis of AMANDA-II data and the partial
completion of the IceCube neutrino detector at the south
pole, the field of high-energy neutrino astronomy
continues its exciting progress. The AMANDA-II data
collected during the period 2000-03 have been analysed in
a search for a diffuse flux of high-energy extra-
terrestrial neutrinos from the sum of all sources in the
universe. With no excess of events seen, a 90% confidence
level upper limit on an E-2 flux of E2 Phi < 7.4 x 10-8
GeV cm-2 s-1 sr-1 was obtained. The astrophysical
implications of this bound and of others obtained for
specific models (including atmospheric charm) will be
discussed. First results from the IceCube 9 string array,
and detection prospects for the currently operating 22
string array will be discussed.
|
|
Speaker
|
Hooper Dan
|
|
Institution
|
Fermilab
|
|
Title
|
High energy neutrinos from
extragalactic
sources
|
|
Abstract
|
Neutrino astronomy is rapidly reaching the level of sensitivity thought to be
required to observe the first high energy and ultra-high energy neutrinos from
extragalactic sources, including gamma ray bursts, active galactic nuclei and
starburst galaxies. I will summarize the experimental and theoretical status of
this rapidly developing field and discuss what we can learn from the first
detections of high energy cosmic neutrinos.
|
|
Speaker
|
Horiuchi Shunsaku
|
|
Institution
|
University of Tokyo
|
|
Title
|
Dark matter annihilation from
cosmological IMBH
|
|
Abstract
|
We explore contributions to the extragalactic gamma-ray
background from neutralino dark matter pair-annihilations,
from dark matter density enhancements surrounding
intermediate-mass black holes (IMBHs). These enhancements,
termed minispikes, are thought to be formed during the
formation of IMBHs. Focusing on two IMBH formation
scenarios, we take into account later minispike depletion
processes and sum contributions from a cosmological
distribution of IMBHs with maintained minispikes. We show
that as a result contributions are increased by 1 to 3
orders. We also determine the dark matter annihilation
spectra into monochromatic gamma-rays, which may provide a
potential `smoking-gun' signature of neutralino dark matter
in the gamma-ray background.
|
|
Speaker
|
Ichikawa Kazuhide
|
|
Institution
|
Institute for Cosmic Ray
Research
|
|
Title
|
Energy budget of cosmic rays, magnetic fields and radio background
|
|
Abstract
|
We consider energy budget of cosmic rays and magnetic fields assuming the
magnetic field would leak into intergalactic space with the cosmic rays. Then, we
compute the radio background produced by cosmic ray electrons in that
magnetic fields and compare with the observed radio background.
|
|
Speaker
|
Jouvenot Fabrice
|
|
Institution
|
University of Liverpool
|
|
Title
|
Sensitivity of a cubic-kilometre deep-sea neutrino
telescope - KM3NeT - to galactic sources
|
|
Abstract
|
A future km3-scale neutrino telescope in the Mediterranean
Sea, offers the possibility to significantly constrain
models of cosmic ray propagation in the galaxy as well as
the acceleration mechanisms involved in their production
within astrophysical sources.
|
|
Speaker
|
Kashti Tamar
|
|
Institution
|
Weizmann Institute of Science
|
|
Title
|
Flavoring Astrophysical Neutrinos: Flavor Ratios Depend on Energy
|
|
Abstract
|
Electromagnetic (and adiabatic) energy losses of pions and
muons modify the flavor ratio (measured at Earth) of
neutrinos produced by pion decay in astrophysical sources.
We saw that the flux ratio, $\Phi_{\nu_e}:\Phi_
{\nu_\mu}:\Phi_{\nu_\tau}$, is modified from 1:1:1 at low
energy to 1:1.8:1.8 at high energy. The transition occurs
over 1-2 decades of nuetrino energy, and is correlated with
a modification of the neutrino spectrum. For gamma-ray
bursts, e.g., the transition is expected at ~100 TeV, and
may be detected by km-scale neutrino telescopes.
Measurements of the transition energy and energy-width will
provide unique probes of the physics of the sources. Pion
and muon energy losses also affect the ratio of $\bar\nu_e$
flux to total neutrino flux, which may be measured at the W-
resonance (6.3 PeV): It is modified from 1/6 (1/15) at low
energy to 1/9 (practically 0) at high energy for neutrinos
produced in pp ($p\gamma$) interactions.
|
|
Speaker
|
Kocharovsky Vladimir
|
|
Institution
|
Institute of Applied Physics
RAS
|
|
Title
|
The converter acceleration mechanism for potential
sources of ultra-high energy cosmic rays
|
|
Abstract
|
We consider particle acceleration in relativistic shocks or
shear flows, which are most likely sources of ultra-high
energy cosmic rays. We compare acceleration mechanisms and
show that the converter mechanism, suggested recently (Phys.
Rev. D 68 (2003) 043003, ASS 297 (2005) 21-30), is the least
sensitive to the geometry of the magnetic field in
accelerators and can routinely operate up to cosmic-ray
energies close to the fundamental limit. The converter
mechanism utilizes multiple conversions of charged particles
into neutral ones (protons to neutrons) and back by means of
photon-induced reactions or inelastic nucleon-nucleon
collisions. It outperforms the standard diffusive shock
acceleration in Active Galactic Nuclei, Gamma-Ray Bursts,
and microquasars. The main advantages of the converter
mechanism in such environments are that it greatly
diminishes particle losses downstream and avoids the
reduction in the energy gain factor. We also analyze the
properties of gamma-ray and neutrino radiation, which
accompanies acceleration of particles via the converter
mechanism and can provide an evidence for the latter. In
particular, we point out the fact that the opening angle of
the radiation beam-pattern is energy dependent, which is
relevant to the observability of the cosmic-ray sources as
well as to their timing properties.
|
|
Speaker
|
Kotera Kumiko
|
|
Institution
|
Institut d'Astrophysique de
Paris
|
|
Title
|
Inhomogeneous magnetic fields and the Second Knee
in the cosmic ray spectrum
|
|
Abstract
|
There seems to be a consensus among various experiments on
the existence of the Second Knee around E=3x1017 eV in the
cosmic ray spectrum. This feature could be the signature of
the end of the galactic component and the emergence of the
extra-galactic one, provided that the latter cuts off at
low energies.
Recent analytical calculations have shown that this cut-off
could be naturally explained by a "magnetic horizon" effect
(Lemoine 2005,Berezinsky & Gazizov, 2006): low energy
protons diffuse on extra-galactic magnetic fields and cannot
reach the observer within a given time.
We study the influence of inhomogeneous magnetic fields on
the magnetic horizon, using a newly written original
semi-analytical propagation code. Our results indicate that,
at a fixed value of the volume averaged <B>, the amplitude
of the low energy cut-off is mainly controled by the
strength of magnetic fields in the voids of the large scale
structure distribution. Our simulations also enable us to
constrain some crucial parameters: <B> should be greater
than 0.3 nG and not exceed 10 nG for a source density
n_s=10^(-5) Mpc^(-3).
|
|
Speaker
|
Kowalski Marek
|
|
Institution
|
Humboldt University
|
|
Title
|
Searching for high-energy neutrino transient sources
|
|
Abstract
|
Transient high-energy neutrino sources, such as Gamma-Ray Bursts (GRBs)
and core-collapse Supernovae (SNe) are predicted to be, constitute both
chance and challenge. I will briefly discuss the astrophysical motivation for
high-energy neutrinos from SNe and GRBs and some of the consequences
(chances) their detection would have for astrophysics and particle-physics.
We then turn to the observational challenge. A novel search strategy will be
discussed, which consists of complementing large neutrino telescopes (such
as IceCube) with optical follow-up observations. By searching for GRB
afterglows or rising SN lightcurves through optical follow-up observations,
one can significantly improve the perspectives for the detection of such
sources. We describe first steps towards the creation of a global network of
optical telescopes for follow-up observations of neutrino events and discuss
its prospects.
|
|
Speaker
|
Kryvdyk Volodymyr
|
|
Institution
|
National Taras Shevchenko University of Kiev
|
|
Title
|
Cosmic ray and GRB from collapsing star
|
|
Abstract
|
Cosmic ray acceleration and the non-thermal radiation from
the magnetized collapsing stars with the initial dipole
magnetic fields are considered. The analysis of particles
dynamics and its acceleration in the stellar magnetosphere
under collapse show that the collapsing stars can by
powerful sources of cosmic rays. The fluxes of cosmic rays
from collapsing stars depend on its magnetic field and the
initial particle spectrum in the magnetospheres. The
collapsing stars can by also powerful sources of non-
thermal radiation produced by the interaction of charged
particles with the magnetic field. This radiation can be
observed as GRB.
|
|
Speaker
|
Laffranchi Marco
|
|
Institution
|
ETH Zurich
|
|
Title
|
The ArDM, a ton-scale liquid argon experiment for
direct detection of Dark Matter
|
|
Abstract
|
The ArDM project aims at developing and operating large noble liquid
detectors to search for direct evidence of Weakly Interacting Massive Particles
(WIMP) as Dark Matter in the universe. The initial goal is to design, assemble
and operate an approximately 1 ton liquid argon prototype to demonstrate
the feasibility of a ton-scale experiment with the required performance to
efficiently detect and sufficiently discriminate backgrounds for a successful
WIMP detection. Our design addresses the possibility to independently detect
ionization and scintillation signals. In this talk, the concept of the detector
and the status of the construction are described.
|
|
Speaker
|
Leisos Antonis
|
|
Institution
|
Hellenic Open University
|
|
Title
|
A sea top infrastructure for calibrating an underwater
neutrino telescope
|
|
Abstract
|
The HEllenic LYceum Cosmic Observatories Network-
HELYCON collaboration is constructing a network of
detector stations distributed over three extended
geographical areas. The goal of HELYCON is to observe
Extensive Air Showers and to collect data corresponding to
the flux, the direction and possible correlations between
very energetic cosmic rays. In this report the design, the
construction and the performance of a prototype detector
array is presented. The results of a feasibility study on
the use of HELYCON detectors for the calibration of the
Mediterranean neutrino telescope, KM3NeT, are also
presented.
|
|
Speaker
|
Levine Ilan
|
|
Institution
|
Indiana University South Bend
|
|
Title
|
COUPP, A Dark Matter Search Experiment Using Superheated Liquids
|
|
Abstract
|
COUPP - The Chicagoland Observatory for Underground Particle
Physics (E961 at Fermilab) is a search experiment using
moderately superheated heavy liquids in a bubble chamber as
a WIMP dark matter target. I will discuss the experimental
technique, the data taken with a 2.2 kg test chamber, and
the progress toward ~67 kg modules currently under
construction.
|
|
Speaker
|
Liolios Anastasios
|
|
Institution
|
Aristotele University of
Thessaloniki
|
|
Title
|
The search for the direct detection of solar axions by CAST experiment
|
|
Abstract
|
We describe the present status of the CERN Axion Solar
Telescope (CAST), an experiment dedicated to the direct
detection of solar axions. The results from the CAST phase
I, with vacuum inside the magnet bores, gave an upper
limit on the axion-photon coupling of ga < 8.8×10-11 GeV-1
for ma < 0.02 eV, the best experimental limit so far by
nearly an order of magnitude. In order to extend CAST
sensitivity to higher axion rest masses, the experimental
setup was upgraded (CAST phase II) in order to operate
with the magnet bores filled with a buffer gas (4He at
first and later on 3He). In order to fully exploit the
discovery potential of the experiment, CAST plans to
expand its solar axion rest mass sensitivity towards
higher masses and lower its energy threshold.
|
|
Speaker
|
Lionetto Andrea
|
|
Institution
|
INFN Roma Tor Vergata
|
|
Title
|
Dark Matter in Models with Anomalous U(1)
|
|
Abstract
|
The appearence of extra anomalous U(1) gauge groups is a
generic prediction of many string inspired scenario.
We study in this framework the possible dark matter
candidate and we give an overview of the direct and indirect
detection prospects.
|
|
Speaker
|
Lisanti Mariangela
|
|
Institution
|
SLAC, Stanford University
|
|
Title
|
Unification and Dark Matter in a Minimal Scalar Extension of the Standard Model
|
|
Abstract
|
The six Higgs doublet model is a minimal extension of the Standard Model (SM)
that addresses dark matter and gauge coupling unification. Another Higgs
doublet in the 5 representation of a discrete symmetry group, such as
S_6, is added to the SM. The lightest components of the 5-Higgs are neutral,
stable and serve as dark matter so long as the discrete symmetry is not broken.
Direct and indirect detection signals, as well as collider signatures are
discussed. The five-fold multiplicity of the dark matter decreases its mass and
typically helps make the dark matter more visible in upcoming experiments.
|
|
Speaker
|
Longo Francesco
|
|
Institution
|
University of Trieste and INFN
Trieste
|
|
Title
|
Gamma-ray astrophysics with
GLAST
|
|
Abstract
|
The Gamma ray Large Area Space Telescope (GLAST) is the
next-generation high energy gamma-ray astronomy mission,
scheduled for launch in late 2007. The observatory is
composed by two instruments. The Large Area Telescope (LAT)
will survey the sky in the energy range from 20 MeV to >300
GeV, while the GLAST Burst Monitor (GBM) will monitor
gamma-ray bursts and other transients in the 10 keV to 25
MeV range. The LAT's high angular resolution, large
effective area and broad field of view provide nearly two
orders of magnitude increase in sensitivity over previous
missions. With such unprecedented capability, GLAST will
increase our understanding of the high energy emission of
black holes and active galaxies, pulsars and supernova
remnants, gamma-ray bursts, solar flares and diffuse
sources. Many of its science investigations will benefit
from coordinated, multiwavelength observations. In
particular, GLAST LAT will be the only instrument sensitive
in a common energy range with ground based TeV telescopes.
The GLAST team welcomes cooperative efforts from observers
in all wavebands to maximize its scientific return. In
particular I will review the current status of the
observatory and the LAT instrument performance, with special
emphasis on GLAST's broad science objectives and the
connection with TeV instruments.
|
|
Speaker
|
Maccione Luca
|
|
Institution
|
SISSA - Trieste
|
|
Title
|
Diffuse gamma-ray and neutrino
emissions of
the Galaxy
|
|
Abstract
|
We construct simulated maps of the expected neutrino and
gamma-ray emissions above 1 TeV due to the hadronic
scattering of cosmic rays (CR) with the interstellar medium
(ISM). We estimate the spatial distribution of primary
nuclei by solving numerically the diffusion equation. We
consider several models of the galactic magnetic field (GMF)
finding no significant dependence of our results on the
uncertainties involved. Assuming that CR sources are
supernova remnants, we use a distribution of those objects
as estimated from observations of pulsars and progenitor
stars. For the ISM distribution, we adopt most recent data
both for the atomic and molecular hydrogen. Due to the major
uncertainties in the determination of hydrogen maps, we
compare predictions obtained with different models. With
respect to previous results, we find the neutrino and
gamma-ray emissions to be more peaked along the galactic
plane (GP) and in the galactic centre, improving
significantly the perspectives of a detection. We compare
our predictions with present experimental limits for both
gamma-rays and neutrinos and show that air shower array
experiments may soon be able to detect the gamma-ray
emission from the GP. Finally, we discuss the perspectives
that a km3-size neutrino telescope based in the North
hemisphere has to measure the diffuse emission from the
inner Galaxy.
|
|
Speaker
|
Marcowith Alexandre
|
|
Institution
|
LPTA Montpellier, France
|
|
Title
|
The Fermi acceleration process in astrophysical shocks
|
|
Abstract
|
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The Fermi acceleration of energetic particles in
astrophysical shock fronts appears as a key process to
explain the extreme cosmic ray energies that may be produced
in different astrophysical sources. The efficiency of the
Fermi process mostly relies on the properties of the
turbulence that develops in the up- and down-stream flows.
This work concerns about the consequences of a strong
magnetic field amplification in the shock precursor through
the excitation of the MHD turbulence by the streaming of
accelerated cosmic rays. Estimates on the turbulence
spectrum, anisotropy and coherence length up-stream, the
effect of relaxation and scale compression down-stream,
necessary to properly account for the particle transport,
are investigated using analytical and numerical
calculations. The recent X and gamma-ray observations of
supernova remnants and also gamma-ray burst are used to
discuss and constrain the previous theoretical investigation.
|
|
Speaker
|
Margiotta Anna
|
|
Institution
|
INFN and Università di Bologna
|
|
Title
|
The ANTARES neutrino telescope
|
|
Abstract
|
The ANTARES collaboration is building an underwater
telescope for high energy neutrinos in the Mediterranean
Sea, 40 km off the French coasts. The final detector will
consist of 900 photomultipliers (PMTs) arranged in a 3-
dimensional array of 12 lines, at a depth of about 2500 m
and will be completed by January 2008.
In March 2006, the first line was successfully connected
to the deep undersea junction box. Presently, 5 lines are
connected and continuously sending data to the shore
station. With its 375 PMTs, ANTARES is already the largest
underwater neutrino telescope in the world.
In this talk, the status of the experiment and preliminary
results will be reported.
|
|
Speaker
|
Marsella Giovanni
|
|
Institution
|
Dip.Ingegneria
dell'Innovazione – Università
del Salento - Lecce
|
|
Title
|
Time structure in shower longitudinal development
with ARGO-YBJ detector
|
|
Abstract
|
ARGO-YBJ is a full coverage layer of Resistive Plate
Counters (RPCs) covering
an area of about 5.800 m2 installed at the Yanbaijing
Laboratory (Tibet, P.R.
China) at 4.300 m a.s.l. The detector reads out and
digitizes the space and time
information with a high granularity (56x62 cm2 pads and 1
ns accuracy in time
measurements) making it a unique device for a detailed
study of atmospheric
shower characteristics. This peculiarity allows a wide
range of cosmic ray physics
in the energy range between 300 GeV and 100 TeV. A study
on shower phenomenology
and time structure in shower longitudinal development with
ARGO-YBJ detector is
presented.
|
|
Speaker
|
Matsumoto Shigeki
|
|
Institution
|
Tohoku University
|
|
Title
|
Cosmology of Gravitino LSP Scenario with Right-Handed Sneutrino NLSP
|
|
Abstract
|
We consider supersymmetric model with right-handed (s)
neutrinos where the neutrino masses are purely Dirac type.
We discuss cosmology based on such a scenario, paying
particular attention to the case that the gravitino is the
LSP while the right-handed sneutrino is the next-LSP. It
will be shown that the cosmological constraints on the
gravitino-LSP scenario (in particular, those from the big-
bang nucleosynthesis) are drastically relaxed in such a
case. We will also show that the dark matter abundance
reproduced by the LHC experiment will provide us important
information for the small scale structure problem in our
galaxy.
|
|
Speaker
|
McKay Douglas
|
|
Institution
|
University of Kansas
|
|
Title
|
Neutrino telescopes, cross
sections and fluxes
|
|
Abstract
|
When UHE neutrino events are observed, the physics of sources (flux) must be
separated from the physics of detection (cross sections). We propose several
simple diagnostics that suggest the cross section and flux can be cleanly
disentangled. We show the simple picture holds up for a wide range of
energy behaviors and normalizations of flux and cross section. We illustrate
the application of the ideas to several present and future telescope
configurations.
|
|
Speaker
|
McKinsey Dan
|
|
Institution
|
Yale University
|
|
Title
|
First results from the XENON10 direct dark matter search
|
|
Abstract
|
The XENON10 experiment at Gran Sasso National Laboratory uses a 15 kg
dual phase xenon time projection chamber to search for dark matter in the
form of weakly interacting massive particles (WIMPs). The detector measures
simultaneously the scintillation and the ionization produced by radiation in
pure liquid xenon, to discriminate signal from background down to 4.5 keV
nuclear recoil energy. Ionization electrons are extracted into the xenon vapor
where they produce a large proportional scintillation signal in a grid
assembly. Both prompt and proportional scintillation light are detected by
PMT arrays on the top and bottom of the active liquid xenon volume. The
distribution of proportional scintillation light in the top PMT array can be
used to achieve xy position resolution, while the ionization drift time gives
position resolution in the z direction. This allows the definition of a low-
background fiducial volume. A blind analysis of 58.6 live days of data,
acquired between October 6, 2006 and February 14, 2007, and using a
fiducial mass of 5.4 kg, excludes previously unexplored parameter
space, setting a new 90% C.L. upper limit for the WIMP-nucleon spin-
independent cross-section of 8.8E-44 cm2 for a WIMP mass of 100 GeV, and
4.5E-44 cm2 for a WIMP mass of 30 GeV.
|
|
Speaker
|
Mena Olga
|
|
Institution
|
INFN Sez. di Roma - “La
Sapienza”
|
|
Title
|
Ultrahigh-energy neutrino flux
as a probe of
large extra dimension
|
|
Abstract
|
A suppression in the spectrum of ultrahigh-energy (UHE, $\gtrsim
10^{18}$~eV) neutrinos will be present in extra-dimensional scenarios,
due to enhanced neutrino-antineutrino annihilation processes with the
supernova relic neutrinos. In this scenario, neutrinos can not be
responsible for the highest energy events observed in the UHE cosmic
ray spectrum. A direct implication of these extra-dimensional
interactions would be the absence of UHE neutrinos in ongoing and
future neutrino observatories, such as in ANITA and ARIANNA neutrino
telescopes.
|
|
Speaker
|
Mezzetto Mauro
|
|
Institution
|
INFN – Sezione di Padova
|
|
Title
|
HARP results on pion
production on carbon,
nitrogen and oxygen
|
|
Abstract
|
Motivated by the importance of the measurement of proton and
pions interactions on carbon, nitrogen and oxygen for tuning
hadronic interaction models used in neutrino flux and
extensive air shower simulations, we analyze pion production
in proton and pion reactions on C, N2 and O2 up to 12GeV/c
measured by the fixed target experiment HARP at CERN-PS.
We present momentum spectra of positive and negative pions
and compare them with predictions of frequently used
hadronic interaction models.
|
|
Speaker
|
Michelson Peter
|
|
Institution
|
Stanford University
|
|
Title
|
The Gamma-ray Large Area Space
telescope
|
|
Abstract
|
The Gamma ray Large Area Space Telescope (GLAST) is the
next-generation high energy gamma-ray astronomy mission,
scheduled for launch in Fall 2007. The observatory
comprises two instruments. The Large Area Telescope (LAT)
will survey the sky with unprecedented sensitivity in the
energy range from 20 MeV to >300 GeV, while the GLAST
Burst Monitor (GBM) will monitor gamma-ray bursts and
other transients in the 5 keV to 25 MeV range. The LAT s
high angular resolution, large effective area, and broad
field of view provide nearly two orders of magnitude
increase in sensitivity over previous missions. GLAST
promises major advances in our knowledge and understanding
of the high energy emission of black holes and active
galaxies, pulsars and supernova remnants, gamma-ray
bursts, and diffuse sources. All GLAST data will be
public after the first year of observation. With many of
its science investigations benefiting greatly from
coordinated, multiwavelength observations, the GLAST team
welcomes cooperative efforts from observers in all
wavebands to maximize scientific return. In this talk I
will summarize the current status of the observatory
testing and instrument performance, as well as review the
mission's broad science reach.
|
|
Speaker
|
Moskalenko Igor
|
|
Institution
|
Stanford University
|
|
Title
|
Matter and antimatter in Cosmi
Ray
|
|
Abstract
|
The fraction of antimatter in cosmic rays (CR), positrons,
antiprotons, and yet-to-be-discovered antinuclei, is small,
however it can provide us with unique information on our
Galactic environment. Most of the antimatter in CRs,
positrons and antiprotons, is produced in energetic
interactions of CR nuclei, primarily protons, with
interstellar gas. The spectra of these "secondary" particles
depends on the Galactic CR proton distribution as well as
the conditions in the interstellar medium, such as the
spectrum of interstellar turbulence, distribution of the
interstellar radiation and magnetic fields, gas density, the
Galactic wind, etc. Their propagation in the heliosphere
depends on the solar modulation. Contrary to other CR
species, the production spectra of secondary positrons and
antiprotons depend mostly on the ambient proton spectrum;
this enables us to study the effects of their propagation in
the interstellar medium and in the heliosphere. The
production of secondary CRs is also intimately related to
that of the Galactic diffuse emission, which dominates the
gamma-ray sky; the gamma rays deliver information directly
from distant locations, thus enabling us to study the
Galactic CR distribution independent of propagation effects.
Additionally, the spectra of CR positrons and antiprotons,
and diffuse gamma rays, could contain signatures of exotic
ph.
|
|
Speaker
|
Holger Motz
|
|
Institution
|
Antares Collaboration
|
|
Title
|
Dark Matter Sensitivity of
ANTARES
|
|
Abstract
|
The ANTARES neutrino telescope is under construction in the
Mediterranean Sea near Toulon. The telescope is built to
search for astrophysical neutrino point sources and for
neutrinos created in self-annihilation of Dark-Matter
particles. A likely source of such neutrino emission would
be the Sun, where Dark-Matter particles are expected to
accumulate. Predictions of the neutrino flux originating
from the Sun have been made based on the minimal
Supergravity (mSugra) model including the effect of neutrino
oscillations. Within mSugra the lightest supersymmetric
particle, if a neutralino, is a possible candidate for cold
Dark Matter. The neutrino flux from the Sun is given for a
large range in the mSugra parameter space. Using the general
features of ANTARES in the energy range from 10 GeV to 400
GeV the anticipated exclusion limits for indirect neutralino
detection have been calculated.
|
|
Speaker
|
Carlos Munoz
|
|
Institution
|
Universidad Autonoma de Madrid
& IFT
|
|
Title
|
A comparison between direct
and indirect dark
matter
|
|
Abstract
|
|
|
Speaker
|
Murase Kotha
|
|
Institution
|
Yukawa Institute for
Theoretical Physics
|
|
Title
|
High Energy Neutrino Emission
from Gamma-Ray
Bursts
|
|
Abstract
|
Gamma-ray bursts (GRBs) are the most violent phenomena in
the universe. In the internal-external shock scenarios,
protons may be accelerated as well as electrons. Through
the photomeson or pp reactions, such high energy protons
can produce high energy neutrinos, which may be detected
by large Cherenkov detectors such as IceCube in the
future. Since proton acceleration in GRBs has not been
confirmed, these possibilities are interesting, and
important in order to reveal the connection between GRBs
and ultra-high-energy cosmic-rays.
We have numerically evaluated high energy neutrino
background from GRBs for various scenarios. We discuss
neutrino bursts associated with prompt emission and
neutrino flashes associated with flares. In addition,
neutrino emission during the late phase is also discussed.
We also discuss possible high energy neutrino background
from POP3 GRBs.
|
|
Speaker
|
Nakamori Takeshi
|
|
Institution
|
Kyoto University
|
|
Title
|
Status of the CANGAROO-III
|
|
Abstract
|
The CANGAROO-III telescope system for very-high-energy
gamma-ray
astrophysics consists of four 10-m atmospheric Cherenkov
telescopes located near Woomera, South Australia.
We have been observing southern-sky objects since March
2004. Here we report the status of the system and recent
results of CANGAROO-III observations.
|
|
Speaker
|
Nishimura Hironobu
|
|
Institution
|
Kyoto University
|
|
Title
|
NEWAGE – A direction-sensitive
direct
darkmater search
|
|
Abstract
|
We developed a three-dimensional gaseous tracking device
for a direct direction-sensitive dark matter search. Our
device, we call “micro-TPC” consists of a pixel-type two-
dimensional imaging device which has 768*768 anodes with a
pitch of 0.4 mm and an 100MHz readout system. It is able to
detect the deposit energy and 3D-tracks of charged
particles with a position resolution of sub mm so that it
has a potential to detect the tracks of recoil nuclei
scattered by WIMPs with enough energy and angular
resolution. Furthermore this device can be reject more than
99.99% gamma-ray event by using the information of dE/dx.
We had already operated this device at a surface laboratory
by using 0.2 atm carbon-tetrafluoride(CF4) gas with a
fidutial volume of 21*24*31 cm3 and set the first limit
on the spin-dependent WIMP-proton cross section by a
direction-sensitive method. As a next step we installed it
in the Kamioka Observatory and started operating it.
I will introduce our device and its performance and report
the first underground result of WIMP.
|
|
Speaker
|
Ohnishi Munehiro
|
|
Institution
|
Institute for Cosmic Ray
Research, The
University of Tokyo
|
|
Title
|
Gamma-ray Observation with the Tibet ASgamma Experiment: Present and Future
|
|
Abstract
|
The Tibet air shower array, which has an effective area of
37,000 m2, has been in operation since 1999 at Yangbajing
in Tibet, China at an altitude of 4,300 m above sea level.
We are planning to add a large muon detector array to it and
to improve its sensitivity to cosmic gamma rays with
energies around 100 TeV by discriminating them from
background cosmic-ray hadrons. In this workshop, we will
report on the observation of multi-TeV gamma rays from the
Cygnus region and the Crab Nebula with the present Tibet air
shower array. In addition the possibility of detection of
gamma rays in the 100 TeV energy region in our field of view
will be discussed, based on the improved sensitivity of our
future air shower array.
|
|
Speaker
|
Paneque David
|
|
Institution
|
SLAC/Kipac
|
|
Title
|
Prospects of GLAST to study
blazars
|
|
Abstract
|
.........................................
|
|
Speaker
|
Pastushenko Vladimir
|
|
Institution
|
..............................
|
|
Title
|
Elementary particles, Quantum
Theory of the
Relativity
|
|
Abstract
|
After creation of the Special Theory of the Relativity, the
theory of gravitation in the General Theory of the Relativity
has been created. After creation of the Quantum Theory of
the Relativity, the theory of Quantum Gravitation has been
created. The special case of Quantum Gravitation is the
General Theory of the Relativity and the theory of Electro-
strong Interaction. The special case of the theory of Electro-
strong Interaction is equations of Maxwell.
|
|
Speaker
|
Pavlidou Vasiliki
|
|
Institution
|
University of Chicago
|
|
Title
|
Cosmology and Low-energy
Astrophysics with
Gamma-ray Observations
|
|
Abstract
|
The spectral shape of gamma-ray emission from extragalactic
sources and the extragalactic gamma-ray background in the
GeV and TeV bands encode information about the cosmic star
formation rate, the cosmological distribution and evolution
of active and normal galaxies, as well as about the
properties of the dark matter particle. I will discuss how
we can improve our theoretical understanding of the
spectral shape of guaranteed contributions (those of normal
galaxies and blazars) to the gamma-ray background and how
we can use this understanding in combination with gamma-ray
observations in the GLAST era as an independent constraint
on cosmologically relevant quantities such as the cosmic
star formation rate.
|
|
Speaker
|
Pieri Lidia
|
|
Institution
|
INAF & INFN - Padova
|
|
Title
|
Indirect Detection of clumps
inside the Milky
Way
|
|
Abstract
|
Within the Cold Dark Matter scenario of structure formation,
assuming the dark matter is composed by common candidates
such as supersymmetric particles, the smallest bound
structures have masses as low as 10-6. High-resolution
N-body experiments have shown that a large fraction of these
small structures survive hierarchical clustering and can be
found within the halo of our own Galaxy. These clumps are
expected to boost up significantly the expected annihilation
signal. In this work we perform a thorough analysis of the
prospects for indirect detection of these objects with
GLAST-like experiments, exploring different prescriptions
for the formation and evolution of dark matter clumps, and
allowing the sub-halos shape parameters to vary within the
range currently allowed by numerical simulations. Our
results show that an experiment like GLAST can detect the
annihilation signal if the subhalo mass distribution within
our Galaxy is as clumpy as in the more optimistic, yet not
unrealistic, cases we have explored. We also show that the
annihilation signal comes preferably from the top-massive
rather than the many lightest sub-Galactic clumps.
|
|
Speaker
|
Rodejohann Werner
|
|
Institution
|
Max-Planck-Institute for
Nuclear Physics
|
|
Title
|
Neutrino Mixing and Neutrino
Telescopes
|
|
Abstract
|
Measuring flux ratios of ultra-high energy neutrinos is an
alternative method to determine the neutrino mixing angles
and the CP phase delta. We study general properties of the
relevant neutrino mixing probabilities and obtain explicit
formulae of various flux ratios for neutrinos from pion,
neutron and muon-damped sources. We expand the probabilities
and flux ratios in terms of two small parameters: those are
U_{e3} and the deviation from maximal atmopsheric neutrino
mixing. The first order correction of this expansion is
found to be universal. We investigate which flux ratio from
which source is best suited for measuring certain neutrino
parameters. We also analyze how precise the initial flavor
composition should be known to obtain useful results.
|
|
Speaker
|
Rott Carsten
|
|
Institution
|
Pennsylvania State University
|
|
Title
|
Search for extremely high
energy neutrinos with IceCube
|
|
Abstract
|
Extremely high energy (EHE) cosmic neutrinos (E>10^19eV) are
expected to carry important information about particle
acceleration mechanisms in the universe and the origin of
EHE cosmic-rays. IceCube, currently under construction at
the South Pole, will instrument a volume of one cubic
kilometer by 2011 using 70-80 strings each having 60 digital
optical modules attached to them. The IceCube experiment is
uniquely designed to detect these highly energetic
astrophysical neutrino events. As the neutrino cross-section
increases with energy, the mean free path of neutrinos in
the EHE region becomes shorter than the Earth radius, which
implies that these neutrino events would reach the detector
from the horizon or above. Using detailed Monte Carlo
simulations we show that these EHE signatures can be
distinguished from background atmospheric muon bundles. We
present a search for these events in the data sample
recorded during 2006 using the nine string detector and
discuss improvements in the ongoing analysis of the 2007
dataset collected with 22 strings. We focus in particular on
track and energy reconstruction for these events.
|
|
Speaker
|
Rott Carsten
|
|
Institution
|
Pennsylvania State University
|
|
Title
|
Study of the potential of the IceCube array for
reconstruction of low energy events
|
|
Abstract
|
The IceCube Neutrino Telescope is currently under
construction at the geographic South Pole and will
instrument a volume of one cubic kilometer by 2011. It
currently consists of 22 strings with 60 Digital Optical
Modules each. The AMANDA detector is now fully integrated
into IceCube and provides a more densely spaced sub-array
surrounded by the IceCube strings. IceCube is a multipurpose
detector and its sensitivity extends within a wide energy
range. In this work we will present the study of low energy
fully and partially contained events. As most of the energy
of these events is deposited inside the array, energy can be
more reliably reconstructed. These events are especially
interesting for atmospheric neutrino studies, where
IceCube's sensitivity lies above the range accessible by
other atmospheric neutrino detectors. Furthermore the
analysis of starting tracks is not limited to muon neutrinos
from the northern hemisphere. In this talk we explore
IceCube's physics potential and present reconstruction
methods for this class of events.
|
|
Speaker
|
Salati Pierre
|
|
Institution
|
LAPTH – Université de Savoie
|
|
Title
|
The antiproton cosmic ray signal at TeV energies
|
|
Abstract
|
A new generation of upcoming space-based experiments will soon start to
probe the spectrum of cosmic ray antiparticles with an unprecedented
accuracy and, in particular, will open up a window to energies much higher
than those accessible so far. It is thus timely to carefully investigate the
expected antiparticle fluxes at high energies. Here, we perform such an
analysis for the case of antiprotons. We consider both standard sources as
the collision of other cosmic rays with interstellar matter, as well as exotic
contributions from dark matter annihilations in the galactic halo. Up to
energies well above 100 GeV, we find that the background flux in antiprotons
is almost uniquely determined by the existing low-energy data on various
cosmic ray species; for even higher energies, however, the uncertainties in
the parameters of the underlying propagation model eventually become
significant. We also show that if the dark matter is composed of particles with
masses at the TeV scale, which is naturally expected in extra-dimensional
models as well as in certain parameter regions of supersymmetric models,
the annihilation flux can become comparable to - or even dominate - the
antiproton background at the high energies considered here.
|
|
Speaker
|
Sakurai Nobyuki
|
|
Institution
|
ICRR, University of Tokyo
|
|
Title
|
Telescope Array Experiment
|
|
Abstract
|
Telescope Array (TA) is a EAS detector which is now building
in the western desert in Utah, USA. In order
to estimate the performance of TA, a detailed detector
simulation is being developed in Java. The number
of particles produced during the development of the EAS
shower with various inclinations is calculated by
COSMOS code. The detection efciency of each detector is
evaluated by using the various calibration data
and the results of GEANT4 simulation. And it is taken into
account in estimating the signal. The analysis
methods of the EAS data are also being developed using TA
simulation. This report describes the structure of
our simulation code, the analysis methods and the TA
performance estimation based on our simulation.
|
|
Speaker
|
Savchenko Volodymyr
|
|
Institution
|
BITP, Kiev Ukraine
|
|
Title
|
Sterile Neutrino Warm Dark
Matter constraints
fron
XMM-Newton M31 observations
|
|
Abstract
|
We derive constraints on parameters of a radiatively
decaying warm dark matter particle, e.g., the mass and
mixing angle for a "sterile" neutrino, using XMM-Newton
MOS spectra of the Andromeda galaxy (M31). We show that the
observation of its outer parts can provide nearly the
bigger amount of DM flux, although the X-ray
signal from the outer parts is much less than that from the
central part. This makes better constraints on sterile
neutrino complementary to earlier results that used M31
on-center observations. Our limits are comparable and even
better to the best existing constraints.
|
|
Speaker
|
Senami Masato
|
|
Institution
|
ICRR, University of Tokyo
|
|
Title
|
Dark matter abundance in
universal extra
dimension models
|
|
Abstract
|
Relic abundance of dark matter is investigated in the
minimal universal extra dimension model and the extension
with right-handed neutrinos. The relic abundance in the
minimal universal extra dimension model will be improved by
the recent WMAP data and precise tree cross sections,
compared to my recent result, hep-ph/0605280. Contribution
from KK right-handed neutrino will also be mentioned.
|
|
Speaker
|
Siegal-Gaskins
Jennifer
|
|
Institution
|
University of Chicago
|
|
Title
|
Do tidal stremas constrain
dark matter
substructure?
|
|
Abstract
|
In recent years a number of tidal streams have been observed
in the Milky Way, and it has been suggested that the
existence of coherent tidal streams is incompatible with the
abundance of dark matter substructure predicted by
lambda-CDM models. We investigate whether current and
upcoming observations may constrain dark matter models by
examining the conditions under which coherent tidal streams
can arise. We select a wide range of orbital paths in host
galaxy models similar to the Milky Way, and simulate the
disruption of a self-gravitating satellite on these orbits
in both a smooth dark matter halo and one with substructure.
In general, we find that the presence of substructure has a
less significant effect on the resulting tidal debris than
the orbital path of the satellite in a given host model, and
conclude that the predicted level of substructure is
consistent with current observations. We discuss the
ability of upcoming experiments to probe the distribution of
dark matter on these scales.
|
|
Speaker
|
Smith Nigel
|
|
Institution
|
STFC Rutherford Appleton
Laboratory
|
|
Title
|
Direct Dark Matter Searches
|
|
Abstract
|
Relic abundance of dark matter is investigated in the
minimal universal extra dimension model and the extension
with right-handed neutrinos. The relic abundance in the
minimal universal extra dimension model will be improved by
the recent WMAP data and precise tree cross sections,
compared to my recent result, hep-ph/0605280. Contribution
from KK right-handed neutrino will also be mentioned.
|
|
Speaker
|
Sparvoli Roberta
|
|
Institution
|
University
of Rome
Tor Vergata and INFN Roma
|
|
Title
|
Cosmic
Ray
measurements with space telescope PAMELA: a status report
|
|
Abstract
|
The PAMELA apparatus is designed to study charged particles
in the cosmic radiation over a wide energy range with
unprecedent statistics. The instrument was launched into
space on the 15th of June 2006 and, after a short period of
satellite operation, has been continuously acquiring data.
The scientific objectives addresses by the mission are the
measurement of the antiprotons and positrons spectra in
cosmic rays, the hunt for anti-nuclei as well as the
determination of electron and light nuclei fluxes from
hydrogen to oxygen up to several hundreds of GeV.
This talk will present the potentiality of PAMELA instrument
in cosmic ray measurements. The status of the experiment
approximately 1 year after launch will also be discussed.
|
|
Speaker
|
Spiering Christian
|
|
Institution
|
DESY
|
|
Title
|
Matter
|
|
Abstract
|
Tunka-133, a large EAS Cherenkov array with about 1 km2
sensitive area, is being installed in the Siberian Tunka
Valley, 50 km from Lake Baikal. This is a successor of the
Tunka-25 array operated over several years at he same
location. Tunka-133 will permit a detailed study of
the cosmic ray energy spectrum and mass composition in the
energy range PeV-EeV. The array will consist of 19
clusters, each composed of 7 optical stations. The first
cluster started operation in October 2006. We describe the
data acquisition system, status of the array after summer
2007 and present preliminary results from data taken with
the first cluster.
|
|
Speaker
|
Taylor Andrew
|
|
Institution
|
Max-Planck-Institut fuer
Kernphysik
|
|
Title
|
High-Energy Neutrinos from
Astrophysical
Accelerators
of Cosmic Ray Nuclei
|
|
Abstract
|
Ongoing experimental efforts to detect cosmic sources of
high energy neutrinos are guided by the expectation that
astrophysical accelerators of cosmic ray protons would also
generate neutrinos through interactions with ambient matter
and/or photons. However there will be a reduction in the
predicted neutrino flux if cosmic ray sources accelerate not
only protons but also significant number of heavier nuclei,
as is indicated by recent air shower data. We consider
plausible extragalactic sources such as active galactic
nuclei, gamma-ray bursts and starburst galaxies and demand
consistency with the observed cosmic ray composition and
energy spectrum at Earth after allowing for propagation
through intergalactic radiation fields. This allows us to
calculate the expected neutrino fluxes from the sources,
normalised to the observed cosmic ray spectrum. We find that
the likely signals are still within reach of next generation
neutrino telescopes such as IceCube.
|
|
Speaker
|
Totani Tomonori
|
|
Institution
|
Kyoto University
|
|
Title
|
The Past High Activity of the
Galactic Center
and the 511 keV Annihilation Line Emission
|
|
Abstract
|
There are several lines of evidence that the SMBH at the
Galacticcenter had higher activities in the past than at
present. Here I showthat these lines of evidence can
quantitatively and consistently be explained if the mean
accretion rate during the past ~107 yrs has been ~10^{3-4}
times higher than the current rate, by the picture of
radiatively inefficient accretion flow (RIAF) and associated
outflow that has been successfully applied to Sgr A*. I
argue that this increased rate and its duration are
theoretically reasonable in the Galactic center environment,
while the accretion rate suddenly dropped about 300 years
ago most likely because of the shell passage of the
supernova remnant Sgr A East. Then I show that a significant
amount of positrons should have been created around the
event horizon during the higher activity phase, and injected
into ISM by the outflow. The predicted positron production
rate and propagation distance are close to those required to
explain the observed 511 keV annihilation line emission from
the Galactic bulge, giving a natural explanation for this
enigmatic radiation.
|
|
Speaker
|
Trotta Roberto
|
|
Institution
|
Oxford University Astrophysics
|
|
Title
|
Prospects for direct dark
matter detection in
the CMSSM
|
|
Abstract
|
I will preent an up-to-date analysis of the Constrained
MSSM, performed using Bayesian inference techniques that
allow for the first time to derive constraints that take
into account all sources of uncertainties and all relevant
data, from accelerator bounds to cosmological and
astrophysical observations.
I will discuss prospects of direct dark matter detections
and forecasts for the most probable regions for the
neutralino scattering cross sections, showing that a direct
detection is feasible with the next generation of dark
matter searches. The complementarity of direct searches
with collider searches will be highlighted.
|
|
Speaker
|
Trotta Roberto
|
|
Institution
|
Oxford University Astrophysics
|
|
Title
|
New statistical inference
tools for SUSY
searches
|
|
Abstract
|
The complexity of SUSY models parameter spaces and the
growing amount of data of different nature (from collider
constraints to astrophysical and cosmological observations)
demands the use of more sophisticated statistical tools to
produce model constraints and model predictions.
In this talk I will present a Bayesian framework for
statistical inference and highlight its computational
efficiency and flexibility of use. The case of the
Constrained MSSM will be explored, discussing present
constraints on the model parameters and predictions for the
LHC and the Tevatron.
|
|
Speaker
|
Tluczykont Martin
|
|
Institution
|
DESY
|
|
Title
|
Performance studies of the
combined AMANDA and
IceCube
Neutrino Telescopes of
opportunity Program
|
|
Abstract
|
The current IceCube telescope consists of 22 operational
detector strings of which 13 were recently deployed during the
polar summer season 2006/2007. The full integration of the
AMANDA detector into IceCube operation was finalized in this
season. This includes hardware synchronisation, combined
triggering, common event building and a combined data
analysis strategy. In this contribution the expected
performance of the detector based on Monte Carlo simulations
of the combined detector will be presented.
|
|
Speaker
|
Tluczykont Martin
|
|
Institution
|
DESY
|
|
Title
|
The Multi Messenger Approach and The MAGIC/IceCube Target
of Opportunity Program
|
|
Abstract
|
Current neutrino detectors are approaching a sensitivity
that allows one to detect Active Galactic Nuclei (AGN) in
their high state. However, the expected signals might be
too weak to result in a significant detection.
One possibility to increase the detection chance is to
combine neutrino observations with the rich information
available from observations in the electromagnetic regime
(Multi Messenger Approach). A directional and time-like
coincidence between one or more neutrino events with
a signal, e.g. in the gamma-ray regime, would increase the
significance of the otherwise possibly too weak neutrino
signal. For a comprehensive analysis of simultaneous
neutrino and gamma-ray data several ingredients are
necessary. This contribution will address some of these
ingredients as well as the ongoing target of opportunity
program, a cooperation between the MAGIC gamma-ray and the
AMANDA/IceCube neutrino telescopes.
|
|
Speaker
|
Taboada Ignacio
|
|
Institution
|
University of California
|
|
Title
|
Neutrinos from GRBs and other high energy transients with IceCube.
|
|
Abstract
|
The search for high energy neutrinos from Gamma Ray Bursts
(GRBs) and other short transient sources of gamma rays or
X-rays is one of the main objectives of IceCube. Several
methods have been proposed to search for short neutrino
transients: Coincident searches with satellites, neutrino
triggered optical follow-up monitoring and time-rolling
searches. We will present the sensitivity and the advantages
of each technique. Some of these techniques have been used
with AMANDA and we will present a summary of the results. We
will show that in few years of operation IceCube has the
capability to discover neutrinos from GRBs/transients or
rule out current theoretical predictions.
|
|
Speaker
|
Taoso Marco
|
|
Institution
|
Università degli Studi di
Padova
|
|
Title
|
Gamma-Rays from Dark Matter Mini-Spikes in M31
|
|
Abstract
|
The existence of a population of wandering Intermediate
Mass Black Holes (IMBHs) is a generic prediction of
scenarios that seek to explain the formation of
Supermassive Black Holes in terms of growth from massive
seeds. The growth of IMBHs may lead to the formation of DM
overdensities called "mini-spikes", recently proposed as
ideal targets for indirect DM searches. Current ground-
based gamma-ray experiments, however, cannot search for
these objects due to their limited field of view, and it
might be challenging to discriminate mini-spikes in the
Milky Way from the many astrophysical sources that GLAST
is expected to observe. We show here that gamma-ray
experiments can effectively search for IMBHs in the nearby
Andromeda galaxy (also known as M31), where mini-spikes
would appear as a distribution of point-sources,
isotropically distributed in a \thickapprox 3^{\circ}
circle around the galactic center. For a neutralino-like
DM candidate with a mass m_{\chi}=150 GeV, up to 20
sources would be detected with GLAST (at 5\sigma, in 2
months). With Air Cherenkov Telescopes such as MAGIC and
VERITAS, up to 10 sources might be detected, provided that
the mass of neutralino is in the TeV range or above.
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Speaker
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Turini Nicola
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Institution
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University of Siena and INFN
Pisa
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Title
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The MAGIC experiment
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Abstract
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The Magic Experiment.
The MAGIC experiment is taking data since fall 2003. It�s
large single dish cherenkov telescope allows to explore VHE
sources at lower energies than the competitors. Situated in
the north hemisphere, in the canary island La Palma, it has
produced measurements on galactic and especially
extragalactic sources. The smaller sensitivity will be soon
increased adding a new clone telescope, named MAGICII. The
search for better light sensors and faster readout
electronics will allow the new system to lower again it�s
energy threshold and enlarge the overlap with the new space
based gamma ray observatories such as GLAST and AGILE.
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Speaker
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Taylor James
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Institution
|
University of Waterloo
|
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Title
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Dark Matter on the Smallest
Scales
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Abstract
|
WIMP dark matter should cluster to form dense, gravitationally bound structures
over a huge range of scales, from the scale of galaxy clusters to the scale of our
solar system. I will discuss novel techniques to model structure formation over
this whole range, and what they have to say about dark matter in the solar neighbourhood.
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Speaker
|
Venters Tonia
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Institution
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University of Chicago
|
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Title
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The Spectral Index Distribution of Blazars and
the Spectral Shape of the Blazar Contribution to the EGRB:
Prospects for GLAST
|
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Abstract
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The intrinsic distribution of spectral indices in GeV
energies of gamma-ray�loud blazars is a critical input in
determining the spectral shape of the unresolved blazar
contribution to the diffuse extragalactic gamma-ray
background, as well as an important test of blazar emission
theories. We present a maximum-likelihood method of
determining the intrinsic spectral index distribution (ISID)
of a population of gamma-ray emitters which accounts for
error in measurement of individual spectral indices, and we
apply it to the case of Energetic Gamma-Ray Experiment
Telescope (EGRET) blazars. We find that the most likely
Gaussian ISID for EGRET blazars has a mean of 2.27 and a
standard deviation of 0.20, much narrower than one would
conclude if measurement error had not been accounted for. We
additionally find some indication that FSRQs and BL Lacs may
have different ISIDs (with BL Lacs being harder). We also
test for spectral index hardening associated with blazar
variability for which we find no evidence. We produce
simulated Gamma-ray Large Area Space Telescope (GLAST)
spectral index datasets and perform the same analyses
finding that with improved number statistics, GLAST data
will help us determine the ISIDs with much improved
accuracy. Should any difference exist between the ISIDs of
BL Lacs and FSRQs or between the ISIDs of blazars in the
quiescent.
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Speaker
|
Wagner Stefan
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Institution
|
LSW
|
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Title
|
Constraints on quantum gravity
from fast TeV
gamma-ray
|
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Abstract
|
A number of models of quantum gravity violate Lorentz
invariance and predict an energy dependence of the speed of
light, leading to a dispersion of signals at high energies
that travel over cosmological distances.
The bright and fast flares observed by the Cherenkov
experiment H.E.S.S. in blazar PKS 2155-304 in summer 2006
provides very tight constraints, especially for high-order
terms and dispersion relations with an energy dependence
that is steeper than linear.
We present spectral timing analysis from this event, derive
the limits on dispersion and discuss the limits on violation
of Lorentz invariance.
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Speaker
|
Williams Dawn
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Institution
|
Pennsylvania State University
|
|
Title
|
Development and prospects for a future extension of the IceCube
array with radio and acoustic detectors
|
|
Abstract
|
Neutrinos in the energy range from 1 PeV to above 1 EeV may
provide a clue
to the origin of the highest-energy cosmic rays. However,
the predicted neutrino fluxes at these energies
are essentially beyond the reach of kilometer-scale
detectors such as IceCube, so non-optical technology is
required for the next generation of neutrino
telescope. Some promising avenues are radio and acoustic
detection. The IceCube
optical array at the South Pole, currently under
construction, offers a unique opportunity
for radio and acoustic instruments to co-deploy with optical
modules without additional drilling. The Askaryan Underice
Radio Array (AURA) began deployment in 2006/7 in new IceCube
holes, with 3
prototype digital radio modules in the ice. I will discuss
the status of the AURA
modules and prospects for future radio deployment in the
South Pole ice. I will briefly discuss the status of
acoustic detection at the South Pole.
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Speaker
|
Williams Dawn
|
|
Institution
|
Pennsylvania State University
|
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Title
|
Prospects for tau neutrino detection in IceCube
|
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Abstract
|
Tau neutrinos produce unique signatures in charged current
interactions because of the relatively short decay time of
the tau. These signatures do not have the atmospheric neutrino
background of muon neutrinos. The classic "double bang"
signature of the charged current interaction and subsequent
tau decay can be resolved by the IceCube neutrino detector
for tau energies above 1 PeV. Partially contained double bangs
and the muonic decay channel of the tau will also produce readily
identifiable signatures with larger effective volume and energy
range than the fully contained double bang. I will discuss
the current prospects for tau neutrino
detection in IceCube.
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Speaker
|
Zhao HongSheng
|
|
Institution
|
Univ. Of St. Andrews
|
|
Title
|
Annihilation signatures of the Bullet Cluster and other moving substructures
|
|
Abstract
|
We model the electrons/positrons produced by dark matter
annihilations in the colliding galaxy cluster system 1E0561
(Bullet). These, confined by the magnetic field, mark a
clear track of the bullet, which passes through the main
cluster with a speed of 3000-5000 km/s. Similar trails
exist for moving subhalos (minihalos) in any x-ray
cluster. These trails are often far away from the galactic
astronomical sources, hence offers an unambiguous proof of
the DM annihilation signal through, e.g., inverse-Compton
scattering of cosmic microwave photons.
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