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

Goals: Astroparticle Physics: - Search for Cosmic Antimatter - Searches for Dark Matter Cosmic Ray Astrophysics … AMS-02 Experiment A.Kounine Dark Matter searches with AMS-02 ICHEP 2004 Collect ~10 10 Cosmic Particles (p, D, He, C, …,e,  ) from ~ GV to few TV.

AMS-02 Experiment AMS-02 Experiment Anticoincidence: veto plastic scintillators used in Trigger Time of Flight: 2x2 planes of scintillator hodoscope Resolution  T= ps. Used in Trigger Velocity measurement  L/ct1-ct2  /  0.03  dE/dx measurements Tracker : 8 layers of Si strip planes (6 m 2 ) / 52  pitch Resolution:  = 10  (bending) and 30  (non bending) Rigidity measurements up to ~3TeV dE/dx ~ Z 2 measurement. Conversion of gamma e+e- Magnet: B dipol =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

AMS-02 Experiment Ring Image Cherenkov Detector: radiators (NaF n=1.336 and Aerogel n=1.035) +PMT's  measurement up to 20 GeV/n,  /  % Charge measurements N γ ~Z 2 (  =0.2) up to Z=26 Electromagnetic Calorimeter: 18 planes of Pb+ scintillator fibers Thickness ~16 X o and ~ 0.5 nucl.. Energy resolution: dE/E= /  E[GeV] Used in gamma trigger e,  / h separation ~10 3 E= GeV 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 ~ p=1-300 GeV A.Kounine Dark Matter searches with AMS-02 ICHEP 2004

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

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

Angular Resolution Energy Resolution A.Kounine Dark Matter searches with AMS-02 ICHEP 2004 AMS-02 Detector Performance

The Primordial Antimatter content of the Universe is unknown. ~100 MeV  flux excludes wide antimatter regions up to Mpc Sakharov’s 3 Principles of Baryogenesis : 1. Baryon Number Violation (not confirmed….) 2. C and CP Violation (strong….) 3. 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 Search for Antimatter A.Kounine Dark Matter searches with AMS-02 ICHEP 2004

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

“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

SUSY Dark Matter SYSY postulates spin partners for all known particles MSSM best CDM candidate – neutralino :  0 1 – LSP  0 1  0 1  e + e - – suppressed by spin  0 1  0 1  WW, ZZ,  – vanishing coupling for Bino Plausible signature – low energy anti-protons and anti-deuterons:  0 1  0 1  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

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

Graviton/Gravitino Dark Matter A.Kounine Dark Matter searches with AMS-02 ICHEP 2004 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  m = m WIMP – m sWIMP Feng, Rajaraman, Takayama (2003) gravitino graviton m sWIMP = 0.1, 0.3, 1 TeV (from below)

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

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

Dark Matter Searches: Antiprotons After 3 years of running Background rejection: p/p- > 10 6 and e-/p A.Kounine Dark Matter searches with AMS-02 ICHEP 2004

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

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

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

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

mSUGRA results: Integrated flux from GC as a function of m  in the Focus Point scenario (large m 0 values), for two NFW halo profile parameterizations. R 0 = 8.0 kpc, r 0 = 0.3 GeV/cm 3, a = 20 kpcR 0 = 8.5 kpc, r 0 = 0.4 GeV/cm 3, a = 4 kpc Dark Matter Searches: Photons A.Kounine Dark Matter searches with AMS-02 ICHEP 2004

AMS prospects Launch ready – September 2007 as of now AMS launch is foreseen for end of beginning 2008 AMS-02 will collect data for 3-5 years on ISS: – Antimatter search with a sensitivity – 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