Detection and measurement of g rays with the AMS02 detector Simonetta Gentile Universit di Roma La Sapienza, INFN on behalf of AMS Collaboration

OutlineAMS detector g detection performances:Energy resolutionAngular resolutionPhysics: Dark matter g Minimal Supersymmetric Standard ModelConclusions

The Alpha Magnetic Spectrometer Study of charged particles and nuclei with rigidity 0.5 GV few TV

Direct search for antimatter (antihelium)

Indirect search for Dark Matter .

Designed to take data on International Space Station for more than 3 years. Full assembled in 2008Total statistics expected above 10 10 events

Transition Radiation Detector

Time of Flight scintillator counters

8 layers of Si strips on 5 supporting planes in superconducting magnet

Rich Imaging Cerenkov detector

Electromagnetic calorimeter

Dimensions 3m x 3mx3m,7 tLarge acceptance ~ 0.5m2sr.M.L. ArrudaPoster

Flux Return CoilsDipoleCoilsHe VesselBB2500 Liters Superfluid He Superconducting Magnet

BL2 = 0.9 Tm2

Silicon TrackerRigidity (DR/R < 2% up 20 GeV Protons) with MagnetSigned Charge (dE/dx)8 Layers in 5 planes, ~6.7m2Pitch (Bending): 110 mm (coord. res. 10 mm )Pitch (Non-Bending): 208mm (coord. res. 30 mm )Charge magnitude up Z ~ 26

Electromagnetic Calorimeter10-3 p Rejection with 95% e Efficiency Via Shower Profile1 GeV - 1 TeV pe3D sampling calorimeter9 superlayers of 10 fiber/lead planes each alternate in x and y scintillating fibers viewed by PMT 16.4 X0 radiation length Measure energy (few % resolution) and angle (1 - 0.5 angular resolution) of g, e+,e-

Electromagnetic CalorimeterECAL(E)/E ~ 3% @ 100 GeV e-

Photons in AMS: Two complementary modesConversion mode: g conversionIn upstream layers of the detectorCriteria:very small invariant mass, no TRDActivity in top layer, no particle activity in the rest of detectorSingle photon mode: detectionIn the electromagnetic calorimeter.Criteria: electromagnetic shapeNo activity in the rest of detector

Performances -raysdetection2 complementary modes for photon detection

Performances -raysdetectionEffective Area of Tracker and ECALAcceptance ECAL (TRK) ~ 5 (3)10-2 m2sr from 10 GeV.Proton rejection 105 ; e - ~ 104 ECALECALTrackerTrackerCos(incident angle)

Test beam (conversion mode) Test beam with electrons (producing g up to 7 GeV). Dominant systematic multiple scattering of electrons

OriginEnergy range : 1-300 GeVSources in scope of AMS:Galactic : pulsars, nebulas (VELA, CRAB,)Extra-Galactic : GRBsDiffuse emission : interaction of Charged rays with galactic medium produce (0)Dark Matter R. PereiraPoster

Cosmic Ray FluxesCosmic Rays Composition :p : 88 %He nuclei : 9 %e- : 2 % : < 1% Standard CR spectra follows a "power law" E- with = 2-3

DM signal : exponential cut-off in the spectraNumber of particles inside geometrical acceptance ( assuming 0.45 m2sr )2.8

raysEGRET map E>100 MeV

AMS exposure to galactic gLarger Field of view: 43 GC : ~ 40 daysConversion mode (sel. acc.)Field of View : 23 GC : ~ 15 daysCalorimeter mode (geom. acc.= area x t obs)Revolution : 90

Astrophysical g sources rays emission from Vela PulsarMeasurements and model prediction for diffuse g raysfrom central part of galaxyAMS expectations

Dark MatterOne of the most popular candidates for Dark matter is the neutralino 0, the Lightest Supersymmetric Particle (LSP), neutral, weak-interacting and stable in R-parity conserving SUSY models.

Mixture of superpartners of Higgs boson and W-boson and Z/ bosons (B) Direct detection elastic interaction on nucleus (CDMS, DAMA, EDELWEISS) Indirect detection - Neutralino annihilation 0101 qq , W+W-, ZZ, ... p ,D , (continuum), e+NOT YET OBSERVED!

Gamma rays:They are originated either from annihilation into a final state containing Z or (line signal) or from the decay of other primary annihilation products (continuum signal).Positrons:Primarily from the decay of gauge bosons (e.g.,W+W-) as primary annihilation products; or from heavy quark/lepton decayAntiprotons and antideuterons:Production in WIMP annihilations by hadronization of quark and gluon subproducts.

Possible detectable products from: xx with small physical backgroundsBalloons ray telescopes and satellitesAMSIndirect searches with AMS:detection channels

Dark Matter - ray caseDetection rate (source) : N v 2 (r) dl() d m2LoS SUSYAstrophysics source D M : g Galactic Centre (G. C.)..Nuclear recoils in the dense centerNFW : Navarro-Frenk-White (, , ) = (1, 2, 1) Moore et al. : (, , ) = (1, 1.5, 1.5) Mass densityProfile in our Galaxy

Gamma sensitivity to different DM haloprofilesGamma raysMany experiments will be covering the little known 1-300 GeV range in the next decade.Case considered: Galactic center treated as point source. Favorable conditions to detect or exclude AMSB scenarios; benchmark points of parameter space accesible in case of cuspy profile as well as several KK candidates.

BBMSSM = Minimal SuperSymetric ModelmSUGRA = Minimal SUGRA modelSUGRA = SuperGravity grand unified modelsAMSB = Anomaly Mediated SUSY BreakingA.Jacholkwska et al. Astro-ph/0508349, Phys. Rev D.74 vol 2

Predictions for benchmark fluxesGalactic CentremSUGRA models MC simulationAccelerators & WMAP constraintsVarious DM halo profiles3 years of operationJ. Ellis et al. Eur. Phys. J. C24 (2002) 311A.Jacholkwska et al. Astro-ph/0508349, Phys. Rev D. 74 vol2

ModelBGIKLm98.3153.6143.0571.5187.2m059.0116.0178.0999.0299.0tan 10.20.35.38.247relic0.120.130.130.090.10n (NFW)0.20.10.80.32.1n (NFW cuspy)5.53.524.59.164.7n (Moore)15.810.270.426.2185.4

CONCLUSIONSAMS02 is magnetic spectrometer on International Space Station, ready in 2008: Large Acceptance Long term operation AMS02 will provide:Precise Cosmic Ray elemental and isotopic fluxes in a wide energy rangeDirect search for antimatter (antihelium)Indirect search for Dark Matter (positrons, antiprotrons, gamma).Good g performance detection through conversion and and calorimetric mode:

Angular resolution under ~3 (~0.1) over 10 GeV.Energy resolution ~3 % over 10 GeV

CONCLUSIONSUsing Si-Tracker and EM Calorimeter, AMS-02 will provide new measurements in the range 1-300 GeV .AMS-02 will study several galactic and extragalactic sources as Pulsars, GRBs(At least) constraints in various Cold Dark Models will be provided.

-rays - AMS vs. GLASTSimilarities: Silicon for Tracker, Coverage 1-100 GeVGLAST: quasi-independent detector operation, charged particle vetoing, conversion-optimized

Speak also about Charge-Id up to Z=26, sign from TOF/Tracker, e/p separation between 100-1000 (TOF) and 10000 (ECAL)Before I come to my conclusions