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Astroparticle physics with AMS-02

Astroparticle physics with AMS-02. Andrei Kounine / MIT on behalf of AMS-02 collaboration ICHEP 2004, Beijing. AMS-02 Experiment. Collect ~10 10 Cosmic Particles (p, D, He, C, …,e,  ) from ~ GV to few TV. Goals: Astroparticle Physics: - Search for Cosmic Antimatter

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Astroparticle physics with AMS-02

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  1. Astroparticle physics with AMS-02 Andrei Kounine / MIT on behalf of AMS-02 collaboration ICHEP 2004, Beijing

  2. AMS-02 Experiment Collect ~1010 Cosmic Particles (p, D, He, C, …,e, ) from ~ GV to few TV. • Goals: • Astroparticle Physics: • - Search for Cosmic Antimatter • - Searches for Dark Matter • Cosmic Ray Astrophysics • … A.Kounine Dark Matter searches with AMS-02 ICHEP 2004

  3. AMS-02 Experiment Tracker : 8 layers of Si strip planes (6 m 2). 27.5 / 52m pitch Resolution: = 10  (bending) and 30  (non bending) Rigidity measurements up to ~3TeV dE/dx ~ Z2 measurement. Conversion of gamma e+e- Time of Flight: 2x2 planes of scintillator hodoscope Resolution T=90-150 ps . Used in Trigger Velocity measurement =L/ct1-ct2 /~0.03 dE/dx measurements Anticoincidence: veto plastic scintillators used in Trigger Magnet: Bdipol =0.86 Tesla I~460A NbTi/copper conductor Size: d=1.2m l=0.8 m; Mass 2.3 t E=5.2MJ stored cooled to 1.8K by superfluid He A.Kounine Dark Matter searches with AMS-02 ICHEP 2004

  4. AMS-02 Experiment Transition Radiation Detector: 20 layers of 6mm straw tubes filled with Xe/Co2 interleaved with fleece radiator (22 mm). dE/dx measurements . Separation e/h ~10 3 - 10 2 p=1-300 GeV Ring Image Cherenkov Detector: radiators (NaF n=1.336 and Aerogel n=1.035) +PMT's  measurement up to 20 GeV/n,/~ 0.01-0.04% Charge measurements Nγ~Z 2 (=0.2) up to Z=26 Electromagnetic Calorimeter: 18 planes of Pb+ scintillator fibers Thickness ~16 Xo and ~ 0.5 nucl. . Energy resolution: dE/E=0.023+0.10/E[GeV] Used in gamma trigger e,g / h separation ~10 3 E=1-1000 GeV A.Kounine Dark Matter searches with AMS-02 ICHEP 2004

  5. AMS-02 Detector Performance ECAL resolution: ΔE/E=0.023+0.10/E(GeV) Angular resolution Energy resolution MC Data Data A.Kounine Dark Matter searches with AMS-02 ICHEP 2004

  6. AMS-02 Detector Performance Tracker resolution: Spatial resolution Rigidity resolution Data MC A.Kounine Dark Matter searches with AMS-02 ICHEP 2004

  7. Search for Antimatter • ThePrimordial Antimattercontent of the Universe is unknown. • ~100 MeV g flux excludes wide antimatter regions up to 20-100 Mpc • Sakharov’s 3 Principles of Baryogenesis : • Baryon Number Violation (not confirmed….) • C and CP Violation (strong….) • Deviation from Thermal Equilibrium • … but alternative models predict distant Antimatter local domains ! • Single anti-He Cosmic Rays nucleus  Strong Evidence for Large Anti-matter Domains in the Universe A.Kounine Dark Matter searches with AMS-02 ICHEP 2004

  8. Search for Antimatter Model-independent AMS-01 limit AMS-02 will probe antimatter domains to the edge of Universe A.Kounine Dark Matter searches with AMS-02 ICHEP 2004

  9. “Standard Cosmology” • Dark Energy – 73 % of critical density • Matter – 27 % of critical density • Matter breakdown:– 0.5 % Stars – 4.4 % Barions – 22 % CDM • We do not know what CDM is: – Super Symmetry: LSP – Low Scale Gravity: KK particles – SuperWIMP: Graviton, Gravitino – … A.Kounine Dark Matter searches with AMS-02 ICHEP 2004

  10. SUSY Dark Matter • SYSY postulates spin partners for all known particles • MSSM best CDM candidate – neutralino : 01 – LSP 0101  e+ e- – suppressed by spin 0101  WW,ZZ,  – vanishing coupling for Bino Plausible signature – low energy anti-protons and anti-deuterons: 0101  bb , W+W-, ZZ, Z, H+H-, ...  p– ,anti-D, e+, , +X High energy electrons and photons is also a possibility. A.Kounine Dark Matter searches with AMS-02 ICHEP 2004

  11. Kaluza-Klein Dark Matter • Low Scale Quantum Gravity (Extra Dimensions) generically predict Kaluza-Klein bosons with mass n/R. • BB  e+ e-- dominant channel (~20%) Cheng, Feng, Matchev (2002) A.Kounine Dark Matter searches with AMS-02 ICHEP 2004

  12. Graviton/Gravitino Dark Matter msWIMP = 0.1, 0.3, 1 TeV (from below) • Heavy WIMPs exist in early universe only. • They decay slowly to non-interacting sWIMPs • Signature: photons from decays: WIMP  sWIMP • Decay time is sensitive to Dm = mWIMP – msWIMP graviton gravitino Feng, Rajaraman, Takayama (2003) A.Kounine Dark Matter searches with AMS-02 ICHEP 2004

  13. Dark Matter Searches • AMS-02 is a general purpose particle detector: • p- : Excess at Low Energy and spectrum distortion • at High Energy • D- : Excess at Low Energy • e + :Structure in Spectra above few GeV •  :Energy Spectra differ from “power laws” A.Kounine Dark Matter searches with AMS-02 ICHEP 2004

  14. Background Primary antiprotons from SUSY χ annihilation Dark Matter Searches: Antiprotons 7 models A.Kounine Dark Matter searches with AMS-02 ICHEP 2004

  15. Dark Matter Searches: Antiprotons Background rejection: p/p- > 106 and e-/p- 103-104 After 3 years of running A.Kounine Dark Matter searches with AMS-02 ICHEP 2004

  16. Dark Matter Searches: Anti-deuteron More promising than antiprotons A.Kounine Dark Matter searches with AMS-02 ICHEP 2004

  17. Dark Matter Searches: Positrons e+ AMS02-spectrum after 3 years of data taking: • p/e+ and e-/e+ background rejection: 104-106 • Excellent energy resolution. • ~30% stat error at 300 GeV, ~1% stat error at 50 GeV. A.Kounine Dark Matter searches with AMS-02 ICHEP 2004

  18. Dark Matter Searches: Positrons • Precise data extended to higher energies will be provided by AMS Based on the work of E.A. Balts et al. 99 m  130.3 GeV m  336 GeV A.Kounine Dark Matter searches with AMS-02 ICHEP 2004

  19. Dark Matter Searches: Photons MC Diffusion flux MC Extra-galactic flux A.Kounine Dark Matter searches with AMS-02 ICHEP 2004

  20. Dark Matter Searches: Photons mSUGRA results: Integrated flux from GC as a function of mc in the Focus Point scenario (large m0 values), for two NFW halo profile parameterizations. R0 = 8.0 kpc, r0 = 0.3 GeV/cm3, a = 20 kpc R0 = 8.5 kpc, r0 = 0.4 GeV/cm3, a = 4 kpc A.Kounine Dark Matter searches with AMS-02 ICHEP 2004

  21. AMS prospects • Launch ready – September 2007 as of now AMS launch is foreseen for end of 2007 - beginning 2008 • • AMS-02 will collect data for 3-5 years on ISS: • Antimatter search with a sensitivity 10-9 • Dark Matter content in various channels (p-, D-, e+,) • High statistics cosmic ray measurements • -Astrophysics • Exotics, … A.Kounine Dark Matter searches with AMS-02 ICHEP 2004

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