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Detection and measurement of g rays with the AMS02 detector

Detection and measurement of g rays with the AMS02 detector. Simonetta Gentile Università di Roma La Sapienza, INFN. on behalf of AMS Collaboration. Outline. AMS detector g detection performances: Energy resolution Angular resolution Physics: Dark matter g

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Detection and measurement of g rays with the AMS02 detector

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  1. Detection and measurement of g rays with the AMS02 detector Simonetta Gentile Università di Roma La Sapienza, INFN on behalf of AMS Collaboration Simonetta Gentile XX ECRS ,Lisbon, 5th September, 2006

  2. Outline • AMS detector • g detection performances: • Energy resolution • Angular resolution • Physics: Dark matter g • Minimal Supersymmetric Standard Model • Conclusions Simonetta Gentile XX ECRS ,Lisbon, 5th September, 2006

  3. The Alpha Magnetic Spectrometer • Designed to take data on International Space Station for more than 3 years. • Full assembled in 2008 • Study of charged particles and nuclei with rigidity 0.5 GV– few TV • Direct search for antimatter (antihelium) • Indirect search for • Dark Matter . Total statistics expected above 10 10 events Simonetta Gentile XX ECRS ,Lisbon, 5th September, 2006

  4. Dimensions 3m x 3mx3m,7 t • Large acceptance ~ 0.5m2sr. • 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 M.L. Arruda Poster Simonetta Gentile XX ECRS ,Lisbon, 5th September, 2006

  5. Simonetta Gentile XX ECRS ,Lisbon, 5th September, 2006

  6. Superconducting Magnet Flux Return Coils B B Dipole Coils He Vessel 2500 Liters Superfluid He BL2 = 0.9 Tm2 Simonetta Gentile XX ECRS ,Lisbon, 5th September, 2006

  7. Silicon Tracker • Rigidity (DR/R< 2%up20 • GeV Protons) with Magnet • Signed Charge (dE/dx) • 8 Layers in 5 planes, ~6.7m2 • Pitch (Bending): 110 mm(coord. res. 10 mm) • Pitch (Non-Bending): 208mm (coord. res. 30 mm ) • Charge magnitude up Z ~26 Simonetta Gentile XX ECRS ,Lisbon, 5th September, 2006

  8. Electromagnetic Calorimeter • 3D sampling calorimeter • 9 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- e p 10-3 p Rejection with 95% e Efficiency Via Shower Profile 1 GeV - 1 TeV Simonetta Gentile XX ECRS ,Lisbon, 5th September, 2006

  9. Electromagnetic Calorimeter ECAL (E)/E ~ 3% @ 100 GeV e- Simonetta Gentile XX ECRS ,Lisbon, 5th September, 2006

  10. Photons in AMS: Two complementary modes Single photon mode: detection In the electromagnetic calorimeter. Criteria: “electromagnetic shape” No activity in the rest of detector Conversion mode: g conversion In upstream layers of the detector Criteria:very small invariant mass, no TRD Activity in top layer, no particle activity in the rest of detector Simonetta Gentile XX ECRS ,Lisbon, 5th September, 2006

  11. E/E~ 3% @100 GeV   e+ + e-  EM Shower 6% Single PhotonMode  EM Shower 3% θ~ 0.02 o @100 GeV  EM Shower 1.0o   e+ + e- 0.02o Conversion Mode  e+ + e- Performances -raysdetection • 2 complementary modes for photon detection Simonetta Gentile XX ECRS ,Lisbon, 5th September, 2006

  12. Performances -raysdetection Effective Area of Tracker and ECAL Tracker Tracker ECAL ECAL Cos(incident angle) • Acceptance ECAL (TRK) ~ 5 (3)·10-2 m2·sr from 10 GeV. • Proton rejection 105 ; e - ~ 104 Simonetta Gentile XX ECRS ,Lisbon, 5th September, 2006

  13. Test beam (conversion mode) • Test beam with electrons (producing g up to 7 GeV). • Dominant systematic multiple scattering of electrons Simonetta Gentile XX ECRS ,Lisbon, 5th September, 2006

  14.  Origin • Energy range : 1-300 GeV • Sources in scope of AMS: • Galactic : pulsars, nebulas (VELA, CRAB,…) • Extra-Galactic : GRBs • Diffuse  emission : interaction of Charged rays with galactic medium produce  (0) • Dark Matter R. Pereira Poster Simonetta Gentile XX ECRS ,Lisbon, 5th September, 2006

  15. AMS ~1/s AMS ~1/hour AMS ~1/day Cosmic Ray Fluxes • Cosmic 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 spectra Number of particles inside geometrical acceptance ( assuming 0.45 m2sr )2.8 Simonetta Gentile XX ECRS ,Lisbon, 5th September, 2006

  16. 3C279 Cygnus Region Vela Geminga Crab PKS 0528+134 LMC Cosmic Ray Interactions With ISM PSR B1706-44 PKS 0208-512  rays EGRET map E>100 MeV Simonetta Gentile XX ECRS ,Lisbon, 5th September, 2006

  17. 51º latitude AMS exposure to galactic g Revolution : 90’ Conversion mode (sel. acc.) Calorimeter mode (geom. acc.= area x t obs) Larger Field of view: 43⁰ GC : ~ 40 days Field of View : 23º GC : ~ 15 days Simonetta Gentile XX ECRS ,Lisbon, 5th September, 2006

  18. Astrophysical g sources AMS expectations Measurements and model prediction for diffuse g rays from central part of galaxy • rays emission from Vela Pulsar Simonetta Gentile XX ECRS ,Lisbon, 5th September, 2006

  19. Dark Matter • One of the most popular candidates for Dark matter is the neutralino 0, the Lightest Supersymmetric Particle (LSP),neutral, weak-interacting and stablein R-parity conserving SUSY models. NOT YET OBSERVED! • 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 0101 qq , W+W-, ZZ, ... p ,D ,  (continuum), e+ Simonetta Gentile XX ECRS ,Lisbon, 5th September, 2006

  20. Indirect searches with AMS:detection channels Possible detectable products from: xx with small physical backgrounds • Gamma rays: • They are originated either from annihilation into a final state containing Zγ or γγ (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 decay • Antiprotons and antideuterons: • Production in WIMP annihilations by hadronization of quark and gluon subproducts.  ray telescopes and satellites AMS Balloons Simonetta Gentile XX ECRS ,Lisbon, 5th September, 2006

  21. Dark Matter -  ray case Detection rate (source) : N v2(r) dl() d m2     LoS Astrophysics SUSY • source D M : g Galactic Centre(G. C.)….. Nuclear recoils in the dense center Mass density Profile in our Galaxy NFW : Navarro-Frenk-White (, , ) = (1, 2, 1) Moore et al. : (, , ) = (1, 1.5, 1.5) Simonetta Gentile XX ECRS ,Lisbon, 5th September, 2006

  22. Gamma sensitivity to different DM haloprofiles Gamma rays • Many 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. B B MSSM = Minimal SuperSymetric Model mSUGRA = Minimal SUGRA model SUGRA = SuperGravity grand unified models AMSB = Anomaly Mediated SUSY Breaking A.Jacholkwska et al. Astro-ph/0508349, Phys. Rev D.74 vol 2 Simonetta Gentile XX ECRS ,Lisbon, 5th September, 2006

  23. CONCLUSIONS • AMS02 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 range • Direct 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 ~3º(~0.1º) over 10 GeV. • Energy resolution ~3 % over 10 GeV Simonetta Gentile XX ECRS ,Lisbon, 5th September, 2006

  24. CONCLUSIONS • Using Si-Tracker and EM Calorimeter, AMS-02 will provide new  measurements in the range1-300 GeV . • AMS-02 will study several galactic and extragalactic  sources as Pulsars, GRBs… • (At least) constraints in various Cold Dark Models will be provided. Simonetta Gentile XX ECRS ,Lisbon, 5th September, 2006

  25. -rays - AMS vs. GLAST • Similarities: Silicon for Tracker, Coverage 1-100 GeV • GLAST: quasi-independent detector operation, charged particle vetoing, conversion-optimized Simonetta Gentile XX ECRS ,Lisbon, 5th September, 2006

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