COSMO 09

Session

Dark Matter

7 Sept 2009, 14:15

500/1-001 - Main Auditorium (CERN)

27. Indirect Dark Matter searches with the PAMELA experiment: a wide range cosmic ray observatory

Oscar ADRIANI (Universita' di Firenze and INFN Firenze)

07/09/2009, 14:15

The PAMELA apparatus has been launched in space on June 15, 2006 on the Russian Resurs DK1 satellite, and is continuously taking data since July 2006. The experiment is devoted to the precise and extensive measurements of cosmic ray in space, with main focus on the antiprotons and positrons in the 100 MeV/200 GeV energy range. Primary protons, electrons and light nuclei spectra are also...

28. Indirect dark matter searches with imaging atmospheric Cherenkov telescopes

Emmanuel MOULIN (CEA Saclay, Irfu)

07/09/2009, 14:30

WIMPs annihilations produce very high energy gamma-rays in the final state. These gamma-rays may be detected by imaging atmospheric Cherenkov telescopes. Amongst the plausible targets are the Galactic Center, the center of galaxy clusters, dwarf Sphreroidal galaxies and substructures in Galactic haloes. Recent results from observations of ongoing IACTs will be presented. Constraints on the...

29. Motivations for a New Force in the Dark Sector

Tracy SLATYER (Harvard University)

07/09/2009, 14:45

A new force in the dark sector, with GeV-scale force carriers, can change the expected properties of SUSY WIMP dark matter in significant ways. The annihilation cross section at low velocities is boosted by a Sommerfeld enhancement, perhaps by 2 or 3 orders of magnitude; the WIMP annihilates to the new force carrier, which immediately decays to light particles, bypassing constraints from...

31. Cosmic Rays from Dark Matter Decay

David TRAN (Technical University of Munich)

07/09/2009, 15:00

A series of experiments measuring high-energy cosmic rays have recently reported strong indications for the existence of an exotic source of high-energy electrons and positrons. If interpreted in terms of the decay of dark matter particles, the PAMELA measurements of the positron fraction and the Fermi LAT measurements of the total electron plus positron flux restrict the possible decaying...

30. Galactic evolution and dark matter stability

Francesc FERRER (Washington University in St Louis)

07/09/2009, 15:15

If the dark matter sector in the universe is composed by metastable particles, galaxies and galaxy clusters are expected to undergo significant evolution from high to low redshift. We show that the decay of dark matter, with a lifetime compatible with cosmological constraints, can be at the origin of the observed evolution of the Tully-Fisher relation of disk galaxies and alleviate the problem...

39. Constraints on annihilating Dark Matter from reionization and extragalactic gamma background

Andi HEKTOR (NICPB, Tallin)

07/09/2009, 15:30

The PAMELA, Fermi and HESS experiments (PFH) have shown anomalous excesses in the cosmic positron and electron fluxes. An exciting possibility is that the excesses arises due to annihilating Dark Matter (DM) particles with mass above 700 GeV. We calculate constraints on leptonically annihilating DM using the data of diffuse extragalactic gamma-ray background (EGR) and measurements of the...

37. Constraints on Dark Matter models with large annihilation cross sections from the Early Universe

Fabio IOCCO (IPhT at CEA/Saclay; IAP Paris)

07/09/2009, 15:45

I will show how is it possible to place stringent constraints on high DM self-annihilation cross sections making use of cosmological observables. Current CMB measurements do in fact allow the possibility to limit down to the thermal values for particle masses of few GeV, with constraints that depend only on cosmological paramaters, and are not affected by astrophysical uncertainties. It is...

32. The Constrained NMSSM in the light of a bayesian analysis

Daniel LOPEZ-FOGLIANI (University of Sheffield)

07/09/2009, 16:25

We perform a global exploration of the Constrained Next to Minimal Supersymmetric Standard Model (CNMSSM) using Bayesian statistics. We present an analysis of several observables including collider signatures and predictions for direct detection of dark Matter.

33. Scalar Dark Matter from Inert Doublet Model

Laura LOPEZ-HONOREZ (Universidad Autonoma de Madrid)

07/09/2009, 16:40

The Inert Doublet Model (IDM) provide a rather simple and yet rich extension of the Standard Model for Dark Matter. The dark matter candidate is the lightest neutral scalar of an extra SU(2)_L doublet which is odd under an unbroken Z2 symmetry. It can account for WMAP dark matter for 3 very different mass regimes: the low mass regime with m_dm~10, the middle mass regime with m_dm~m_W, and the...

40. Sterile neutrinos as dark matter

Kalliopi PETRAKI (UCLA)

07/09/2009, 16:55

The discovery of neutrino masses suggests that the Standard Model should be supplemented with new gauge-singlet fermions, the sterile neutrinos. The number and the mass of sterile neutrinos are still undetermined. If one of these fermions has mass of several keV, it can account for the dark matter. Their relic abundance can be produced by several mechanisms. Different mechanisms result to...

34. DAMA/LIBRA and leptonically interacting Dark Matter

Thomas SCHWETZ (Max-Planck-Institute)

07/09/2009, 17:10

The hypothesis that DM has tree-level interactions only with leptons has been proposed as an explanation for the annually modulated scintillation signal in DAMA/LIBRA versus the absence of a signal for nuclear recoils in experiments like CDMS or XENON10. I show that even in such a leptophilic DM scenario there are loop induced DM-nucleus interactions which dominate over DM-electron scattering....

35. A novel determination of the local dark matter density

Riccardo CATENA (SISSA)

07/09/2009, 17:25

We present a novel study on the problem of constructing mass models for the Milky Way, concentrating on features regarding the dark matter halo component. We have considered a variegated sample of dynamical observables for the Galaxy, including several results which have appeared recently, and studied a 7- or 8-dimensional parameter space - defining the Galaxy model - by implementing a...

41. Dark Stars- Dark Matter and shaping the first Stars

Douglas SPOLYAR (Fermi Lab)

07/09/2009, 17:40

We have proposed that the first phase of stellar evolution in the history of the Universe may be Dark Stars (DS), powered by dark matter heating rather than by nuclear fusion. The power source is annihilation of Weakly Interacting Massive Particles (WIMPs). These WIMPs are among the best motivated dark matter (DM) candidates and may be discovered by ongoing direct or indirect detection...

36. Higgs in Space!

Marco TAOSO (University of Padova)

07/09/2009, 17:55

We consider the possibility that the Higgs can be produced in space in dark matter annihilations and its mass determined by measuring the spectrum of gamma ray lines. We provide a simple class of models where the dark matter is a Dirac fermion that couples to a new Z' that dominantly annihilates into top quarks. The class of models under consideration turns out to arise naturally in the...