Andrei Kounine / MITon behalf of AMS-02 collaboration
ICHEP 2004, BeijingICHEP 2004, Beijing
Astroparticle physics with AMS-02
Goals:
•Astroparticle Physics:
- Search for Cosmic Antimatter
- Searches for Dark Matter
• Cosmic Ray Astrophysics
• …
AMS-02 ExperimentAMS-02 Experiment
A.Kounine Dark Matter searches with AMS-02 ICHEP 2004
Collect ~1010 Cosmic Particles (p, D, He, C, …,e, ) from ~ GV to few TV.
AMS-02 ExperimentAMS-02 Experiment
Anticoincidence: veto plastic scintillators used in Trigger
Time of Flight: 2x2 planes of scintillator hodoscopeResolution T=90-150 ps .
Used in Trigger Velocity measurement L/ct1-ct2 /0.03 dE/dx measurements
Tracker : 8 layers of Si strip planes (6 m 2). 27.5 / 52pitchResolution: = 10 (bending) and 30 (non bending)
Rigidity measurements up to ~3TeVdE/dx ~ Z2 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 storedcooled to 1.8K by superfluid He
A.Kounine Dark Matter searches with AMS-02 ICHEP 2004
AMS-02 ExperimentAMS-02 Experiment
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 X
o and ~ 0.5
nucl. .
Energy resolution: dE/E=0.023+0.10/E[GeV]Used in gamma triggere, / h separation ~10 3 E=1-1000 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 ~10 3 - 10 2 p=1-300 GeV
A.Kounine Dark Matter searches with AMS-02 ICHEP 2004
AMS-02 Detector PerformanceAMS-02 Detector Performance
A.Kounine Dark Matter searches with AMS-02 ICHEP 2004
Data MC Data
ECAL resolution:
Energy resolution Angular resolution
ΔE/E=0.023+0.10/E(GeV)
AMS-02 Detector PerformanceAMS-02 Detector Performance
A.Kounine Dark Matter searches with AMS-02 ICHEP 2004
MC
Data
Tracker resolution:
Spatial resolution Rigidity resolution
• The Primordial Antimatter content of the Universe is unknown.
• ~100 MeV flux excludes wide antimatter regions up to 20-100 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 AntimatterSearch for Antimatter
A.Kounine Dark Matter searches with AMS-02 ICHEP 2004
Search for AntimatterSearch 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”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 MatterSUSY Dark Matter
• SYSY postulates spin partners for all known particles
• MSSM best CDM candidate – neutralino : 01 – LSP
010
1 e+ e- – suppressed by spin
010
1 WW, ZZ, – vanishing coupling for Bino
Plausible signature – low energy anti-protons and anti-deuterons:
010
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 MatterKaluza-Klein Dark Matter
Cheng, Feng, Matchev (2002)
Graviton/Gravitino Dark MatterGraviton/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 = mWIMP – msWIMP
Feng, Rajaraman, Takayama (2003)
gravitino graviton
msWIMP = 0.1, 0.3, 1 TeV (from below)
Dark Matter SearchesDark 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: AntiprotonsDark Matter Searches: Antiprotons
Background Primary antiprotons from Background Primary antiprotons from
SUSY SUSY χχ annihilation annihilation
A.Kounine Dark Matter searches with AMS-02 ICHEP 2004
Dark Matter Searches: AntiprotonsDark Matter Searches: Antiprotons
After 3 years of runningAfter 3 years of running
Background rejection:
p/p- > 106 and e-/p- 103-104
A.Kounine Dark Matter searches with AMS-02 ICHEP 2004
Dark Matter Searches: Anti-deuteronDark Matter Searches: Anti-deuteron
More promising than antiprotons
A.Kounine Dark Matter searches with AMS-02 ICHEP 2004
Dark Matter Searches: PositronsDark Matter Searches: Positronsee++ AMS02-spectrum after 3 years of data taking: AMS02-spectrum after 3 years of data taking: • p/e+ and e-/e+ background rejection: 104-106
• 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 130.3 GeV
Dark Matter Searches: PositronsDark 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: Dark Matter Searches: PhotonsPhotons
A.Kounine Dark Matter searches with AMS-02 ICHEP 2004
Diffusion flux
Extra-galactic flux
MC
MC
mSUGRA results: Integrated flux from GC as a function of m 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
Dark Matter Searches: PhotonsDark Matter Searches: Photons
A.Kounine Dark Matter searches with AMS-02 ICHEP 2004
AMS prospectsAMS 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