Das AMS-Experiment Auf der Suche Science nach Dunkler Materie on the ISS im Weltraum
AMS
January 5, 2007
Stefan Schael, RWTH Aachen
S.C.C. Ting
D. Clowe et al., astro-ph/0608407
Density fluctuations
The standard cosmological model
CMB + SDSS + 2dFGRS: !b h 2 = 0.0227 ± 0.008
(M. Tegmark, MIT)
!c h 2 = 0.120 ± 0.005 ! " = 0.70 ± 0.03 ! m = 0.30 ± 0.03 H 0 = 69.6 ± 2.4 h = H 0 / 100 km s #1 Mpc #1 (astro-ph-0507503)
The standard cosmological model In this model the Universe is: •
spatially flat, homogeneous and isotropic on large scales
•
composed of • radiation, ordinary matter (electrons, protons, neutrons and neutrinos)
•
→4.4%
•
cold dark matter, which we know nothing about.
→23%
•
dark energy. which we know less than nothing about.
→73%
Galaxies and large scale structures grew gravitationally from tiny, nearly scale-invariant adiabatic Gaussian fluctuations which we know nothing about.
Dark Matter Searches AMS
e+, p, D, … Charged particles
γ,ν Antares, Km3, … Amanda, Icecube
GLAST CANGAROO, HESS, MAGIC, Veritas, …
Colliders
FNAL, LHC, ILC
Direct detection Ge
WIMP
Dama, CDMS, GENIUS, CRESST, Edelweiss, …
Ge, Si
~20% energy Ionization
Liquid Xe
Heat
Al2O3, LiF ~100% energy
cryogenic detectors
Light
NaI, Xe
~few % energy
CaWo4, BGO
Physics of AMS γ,ν Hubble, Chandra, GLAST, JWST, JDEM Discoveries: (1) Pulsar, (2) Microwave, (3) Binary Pulsars, (4) X Ray sources, solar neutrinos (5) Dark Matter, Dark Energy
…… WHIPPLE, HESS, VERITAS,
…
The highest energy particles are in Cosmic Rays AMS will perform accurate measurements of energetic cosmic rays (0.1 GeV to 2 TeV)
HiRes
AUGER
SUPER K
Physics of Charged Cosmic Rays
π
µ
e
1 9 4 7 : Disco very o f p io ns C. Po w ell 1 9 1 2 : Disco very o f Co sm ic Rays V. Hess
1 9 3 2 : Disco very o f p o sitro n C. D. And erso n
Discoveries of 1 9 3 6 : Muon ( μ) 1 9 3 8 : 1 0 1 5 eV CR 1 9 4 9 : Kaon ( K) 1 9 4 9 : Lam b d a ( Λ) 1 9 5 2 : Xi ( Ξ) 1 9 5 3 : Sig m a ( Σ) AMS is the first precision magnetic spectrometer in Space
•
Primary particles by supernovae explosions, …
•
Secondary particles from nuclear interactions.
•
Diffusion parameters determined from sec./prim. ratios, e.g. B/C ratio
•
Halo size determined from radioactive isotopes e.g. 10Be/9Be ratio (τ(10Be)=1.6 106 yr)
Galactic Diffuse γ−rays
Inner Galaxy : Significance ≥ 5 σ
EGRET All-Sky Map ApJ, 613, 962 (2004)
#4/14
SUSY Dark Matter candidate: Neutralino • •
MSSM and R-parity => Stable DM candidate: the LSP Preferred candidate: The Neutralino
! i = N i,1 B! + N i,2 W!3 + N i,3 H! 10 + N i,4 H! 20
Higgs (h, H, A, H±) m1/ 2 = 350 GeV " m ! = 144 GeV
squarks & sleptonen gaugino
MSSM Parameter: m 0 , m1/2 , tan ! , sign( µ ), A0
•
From astrophysics and cosmology we get: !CDM h 2 = 0.120 ± 0.005
BR(B ! X s" )exp = (3.39
+0.30 ) $10 #4 #0.27
BR(B ! X s" )SM = (3.70 ± 0.30) $10 #4
tan ! = 50, µ > 0, A0 = 0
m1/ 2 = 350 GeV " m ! = 144 GeV
DM Annihilation in Supersymmetry χ
f χ
~
f χ
f
χ
f χ
χ
A
χ
W χ±
f χ
f Z
χ
f ≈37 gammas
Z χ0
W
χ
Z
Dominant χ + χ ⇒ A ⇒ b bbar quark pair
B-Fragmentation known! Hence Spectra of Positrons, Gammas and Antiprotons known!
Galaxy = Super B-Fabrik with rate 1040 x B-Factory
AMS-01: STS-91 1998 Flight Results
•
Energy Range: 100 MeV/n102 1-300 GeV acceptance: 0.5m2sr Choosen configuration for 60 cm height: 20 Layers each existing of: • 22 mm fibre fleece • Ø 6 mm straw tubes filled with Xe/CO2 80%/20% 12 layers in the bending plane 2 x 4 layers in the non-bending plane
Straw Module
Straw tube proportional counter modules: •Straw tubes: 72 µm multilayer aluminium kapton foil, Ø 6 mm , 0.8 ÷ 2.0 m length • Wire: tungsten anode wire, 30 µm Ø, tension ≈ 100 g • Gas mixture: Xe / CO2 (80% / 20%) • Operating HV ~ 1380 V → Gasgain of ~ 3000 • 1 Module → 16 Straws, 100 µm mechanical accuracy • 328 Modules → 5248 Straws
TRD Test Beam Results I • • •
20 layer TRD detector in the test beam at CERN in 2000 we have recorded 3 million events providing signals for protons, electrons, muons and pions at energies from 5-250 GeV Muon events have been used for an intercalibration of the individual straws to a relative accuracy of 2%.
ep+
single layer !
TRD Testbeam Results
TRD single Straw Test to select 5248 good straws
TRD Flight Hardware
AMS-02 Transition Radiation Detector
Performance of the AMS-02 Transition Radiation Detector. Published in Nucl.Instrum.Meth.A558:526-535,2006.
Anti-Protons
Test b eam 1 5 8 GeV/n
M. Battaglia et al., hep-ex/0106207
Post-LEP CMSSM Benchmarks for Supersymmetry M. Battaglia et al., hep-ph/0112013 F
E
M
M
K
H L
J
I B
D
G
A
C
Blue region allowed WMAP, etc. At benchmarks “K” & “M” Supersymmetric particles are not visible at the LHC, but are accessible to AMS.
Benchmark “M” (not accessible to LHC) AMS spectra with Mχ = 840 GeV
K
Zusammenfassung •
Wir haben indirekte Evidenz für die Existenz von Dunkler Materie auf ganz verschiedenen Längenskalen:
!CDM h 2 = 0.120 ± 0.005 !b h 2 = 0.0227 ± 0.0008 •
Wir beobachten Anomalien in den Spektren der kosmischen Höhenstrahlung, die wir mit der Annihilation von Dunkler Materie erklären könnten.
•
Innerhalb der nächsten 5 Jahre erwarten wir Antworten von: –
Beschleuniger Experimenten: Tevatron (2008)
–
Experimenten zur direkten Suche: CMDS, Edelweis, CRESST, XENON, ...
–
Experimenten zur indirekten Suche: • Im Weltraum: PAMELA, GLAST, AMS-02 • Neutrino-Exp.: IceCube, ANTARES • Cherenkov-Teleskope: HESS, MAGIC
J.J Beatty et al., PRL 93 (2004) 241102 PAMELA error > 30%
10 events PAMELA projection A SUSY Model (LSP of 91 GeV) (Projection)
y06K304b
#6/14
Modes of Neutralino Annihilations : tanβ=10 χ1
f
t
χ1
∼ f χ1
χ1
Z0 f
χ1
t
W+ (Z0)
∼ τ
χ1 ∼ τ
χ± (χn0) τ
χ1 W- (Z0)
γ
#7/14
Modes of Neutralino Annihilations : tanβ=53 χ1
b
A0 χ1
b 2
m f ( N1 N 3( 4) ' m * $ ) % " tan ! mW & mA #
#8/14
χ2 : e+/(e++e-) Only tanβ=10
tanβ=30
tanβ=40
χ2 : γ−rays Only n.d.f = 12
tanβ=50
tanβ=52
