Diapositive 1

1
Search for Gamma Rays from LKP Dark Matter in
the UED framework with GLASTa
E.Nussb, J.Cohen-Tanugic and A.Lionettod on
behalf of GLAST DM Exotic Physics WG
eric.nuss_at_lpta.in2p3.fr Outlook 1/
GLAST mission - status 2/ KK Dark Matter with
the LAT 3/ Conclusions ahttp//glast.gsfc.nasa
.gov bLPTA Montpellier II University cSLAC
Stanford University dPhysics Department INFN
Roma Tor Vergata
Preliminary Results
2
GLAST and the LAT detector
I
GBM 10 keV - 25 MeV LAT 20 MeV - 300 GeV
3
Large Area Telescope Overview (PI P.Michelson)
4
LAT cosmic ray run
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Candidate Gamma-ray Event in First LAT Flight
Tower
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GLAST mission status
gt All elements of the GLAST mission have
completed the fabrication phase and are well
into integration. gt LAT, GBM, and spacecraft
assembly complete by mid 2006. gt Delivery of
the instruments for observatory integration
spring/summer 2006. gt Observatory integration
and test summer 2006 through summer CY07.
Short term activities for the collaboration
gt Data Challenge 2 March-gtMay 2006 gt
Beam tests at CERN in summer/autumn 2006
October 2005 16 Tower on the LAT
November 2005 ACD on the LAT
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Kaluza-Klein Dark Matter in (minimal) UED
II
SM in D 5 with 1 compactified extra-dimension
(over S1/Z2 with S1 radius R) Every SM field
(bulk field) possess a KK tower 1-loop level
computation shows that the LKP is well
approximated by the first KK mode of the
hypercharge gauge boson B(1)a aReference
papers Servant, Tait Nucl.Phys.B650391-
419,2003, Bergstrom et al. Phys.Rev.Lett.94131301
,2005
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Limit from Relic Density
WMAP results W CDM h2 0.12 0.02 ? 0.5
TeV mB(1) 1 TeV (depending on the
coannihilation channels) One loop gg-chanels
are avaible in minimal UED models as through
but are out of reach for GLAST due to
mB(1) 0.5 TeV constraint.
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B(1) main annihilation channels
Unlike the supersymmetric case, charged lepton
production is not helicity suppressed and it is
the dominant annihilation channel for masses
0.5 TeV. We assume the branching ratios
computed in Servant, Tait (agree with Bergstrom
et al) Charged fermion production
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Continuum Gamma Ray Flux
We assume a NFW profile with a boost factor
b, centered at Galactic Center The differential
g-ray flux from the GC is NB J(DW )
0.13 105 b for DW 10-5 sr and ?totv
3 10-26 cm3 s-1 for 800 GeV KK DM
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Gamma Rays from LKP
Total number of photons per B(1)B(1)
annihilation where the sum is over all
processes that contribute to primary and
secondary gamma rays with Bf the corresponding
branching ratio. In the following analysis we
have considered both the primary and secondary
g-ray production
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Secondary Contribution
Hadronization and/or fragmentation of q-qbar
final states We include semihadronic decays of
t leptons (fairly hard spectrum) Fornengo et
al Phys.Rev.D70103529,2004 ?
parametrization of dNgqt/dE for a center of
mass energy 1 TeV. We neglect gauge and
Higgs bosons final states.
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Flux from Secondary Contribution
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Gamma Ray Flux Contributions
Total flux contribution from LKP of mB(1)
0.8 TeV and with a boost factor b 200
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Spectral Shapes
Comparison between different spectral shapes
primary and secondary contribution
mSUGRA and E-2 spectra vs LKP
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GLAST simulations
gt Whole sky 'realistic' simulation (DC2 IRF) gt
One Year observations, 30 deg radius FOV Galactic
Center centered
Diffuse background based on GALPROP code (Point
source substracted)
Dark Matter NFW profile, mB(1) 500 GeV
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Preliminary GLAST Sensitivity
We simulated a 1 year map of the sky with a NFW
profile for a LKP with mB(1) 500 GeV For
Ethrs 5 GeV and DW 0.84 sr (30 deg radius
FOV) the total integrated flux leads to
5 s significance ? for NFW profile and 500 GeV
LKP leads to a boost factor of 20 is needed
to reach the 5 sensitivity
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Conclusions
III
gt Our (preliminary) computation indicates that,
in the energy range Eg gt 5 GeV, GLAST could
detect g-rays from GC via LKP annihilations
with moderate boost factors gt Connection with
ground based Cherenkov arrays (continuum and
gamma ray lines) is needed to disantangle KK
signal from standard astrophysical signal (
E-2 spectra) gt But this result strongly depends
on the background model (need of a
precise estimate) gt Major conference, first
GLAST Symposium, being planned for February
2007 at Stanford. International
Organizing Committee formed. gt GLAST is planned
to be launched in 2007 from the Kennedy Space
Center