Cosmic Rays: AMS Experiment...Launched on June 11, 2008 Image credit: NASA/Jerry Cannon, Robert...
Transcript of Cosmic Rays: AMS Experiment...Launched on June 11, 2008 Image credit: NASA/Jerry Cannon, Robert...
Cosmic Rays: AMS Experiment Javier Berdugo (CIEMAT, Madrid)
Frontiers of Astroparticle Physics. La Palma October 11th 2018
P. Mertsch arXiv: 1012.4239 [astro-ph.HE]
Cosmic rays are a sample of solar, galactic and extragalactic matter which
includes all known nuclei and their isotopes, as well as electrons, positrons and antiprotons
Cosmic rays
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Sci. Amer. 276 (1997) 44
p, He + ISM antiparticles + …
+ antiparticles + …
EARTH
p, He
antiparticles
ISM
The collision of cosmic rays with interstellar medium (ISM) produces antiparticles (e+, p, D, …)
The collision of dark matter particles will produce additional antiparticles
Antiparticles in Cosmic Rays and Dark Matter
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Positrons in Cosmic Rays
m=800 GeV
I. Cholis et al., arXiv:0810.5344
m=400 GeV
e± energy [GeV]
e+ /
(e+ +
e- )
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M. S. Turner and F. Wilczek, Phys. Rev. D42 (1990) 1001;
J. Ellis, 26th ICRC Salt Lake City (1999) astro-ph/9911440;
H. Cheng, J. Feng and K. Matchev, Phys. Rev. Lett. 89 (2002) 211301;
S. Profumo and P. Ullio, J. Cosmology Astroparticle Phys. JCAP07 (2004) 006;
D. Hooper and J. Silk, Phys. Rev. D 71 (2005) 083503;
E. Ponton and L. Randall, JHEP 0904 (2009) 080;
G. Kane, R. Lu and S. Watson, Phys. Lett. B681 (2009) 151;
D. Hooper, P. Blasi and P. D. Serpico, JCAP 0901 025 (2009) 0810.1527; B2
Y–Z. Fan et al., Int. J. Mod. Phys. D19 (2010) 2011;
M. Pato, M. Lattanzi and G. Bertone, JCAP 1012 (2010) 020.
Precision measurements of antiparticles requires long exposure time
with detectors with large acceptance and percent level precision.
Flux of antiparticles in cosmic rays
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Experiments operating outside the atmosphere and capable to measure
simultaneously the spectra of the different cosmic ray components.
O. Adriani et al. Nature 458 (2009)
M. Ackerman et al. Phys. Rev. Lett. 108 (2012) 011103
PAMELA: Launched on June 15th 2006
Image: http://wizard.roma2.infn.it/pamela/html/resurs.html
Baikonur Cosmodrome (Kazakhstan)
FERMI Launched on June 11, 2008
Image credit: NASA/Jerry Cannon, Robert Murray
Space based cosmic ray experiments
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CALET, started August 2015
ISS CREAM, started August 2017
AMS, started May 2011
DAMPE, started December 2015
Space-born Cosmic Ray Experiments in operation
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5m x 4m x 3m
7.5 tons
TRD
TOF 1, 2
TOF 3, 4
RICH
ECAL
Magnet and
Veto Counters
Silicon layer 1
Silicon layers 2 - 8
Silicon layer 9
Acceptance: 0.5 m2 sr 08/07/2014 8
USA
MEXICO
UNAM
UNIV. OF TURKU
ASI IROE FLORENCE
INFN & UNIV. OF BOLOGNA INFN & UNIV. OF MILANO-BICOCCA INFN & UNIV. OF PERUGIA
INFN & UNIV. OF PISA INFN & UNIV. OF ROMA
INFN & UNIV. OF TRENTO
NETHERLANDS
ESA-ESTEC NIKHEF
RUSSIA
ITEP KURCHATOV INST.
SPAIN
CIEMAT - MADRID I.A.C. CANARIAS.
ETH-ZURICH UNIV. OF GENEVA
CALT (Beijing) IEE (Beijing)
IHEP (Beijing) NLAA (Beijing) BUAA(Beijing)
SJTU (Shanghai) SEU (Nanjing)
SYSU (Guangzhou) SDU (Jinan)
EWHA KYUNGPOOK NAT.UNIV.
PORTUGAL
LAB. OF INSTRUM. LISBON
ACAD. SINICA (Taipei) CSIST (Taipei)
NCU (Chung Li) NCKU (Tainan)
TAIWAN
TURKEY
METU, ANKARA
CER
N=
JSC
DOE-
NASA
LUPM MONTPELLIER LAPP ANNECY
LPSC GRENOBLE
FRANCE
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BRAZIL
IFSC – SÃO CARLOS INSTITUTE OF PHYSICS
RWTH-I. Aachen KIT-KARLSRUHE
SWITZERLAND
MIT
KOREA
GERMANY
FINLAND
ITALY
CHINA
AMS is an international collaboration based at CERN
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It took 650 physicists and engineers 17 years to construct AMS
Ground Tests and Calibrations Space Qualification (EMI and TV at ESTEC)
1,762 positions and angles with p, e+, e−, pion beams
from 10 to 400 GeV/c
TVT Chamber: P < 10-9 bar Ambient temperature: -90oC to 40oC
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Test Beam at CERN (Calibration)
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237<|R|<290 GV
Positron measurement with AMS
Signal identification from 2D template fit in (∧TRD - ∧CC ) plane
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Positron fraction in cosmic rays with AMS
1 10 100 1000
Energy [GeV]
0
50
100
150
200
250]2
GeV
-1sr
-1s
-2 [
m3
E-
eF
0
5
10
15
20
25 ]2
GeV
-1sr
-1s
-2 [
m3
E+
eF
Latest AMS results on positron and electron fluxes
28.1 million electrons
1.9 million positrons
Energy range from 0.5 GeV to 1 TeV
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Astrophysical point sources like pulsars will imprint a higher anisotropy on the arrival directions of energetic positrons than a smooth dark matter halo.
positrons Isotropic Map
C1 is the dipole moment
The anisotropy in galactic coordinates
Amplitude of the dipole anisotropy on positrons for 16 < E < 350 GeV δ < 0.019 (95% C.I.)
AMS Positron cosmic ray anisotropy
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Models based on very different assumptions describe observed trends of a single measurement.
Positron flux modeling
Many models proposed to explain the physics origin of the observed behavior
1) Particle origin: Dark Matter 2) Astrophysics origin: Pulsars, SNRs 3) Propagation of cosmic rays
Simultaneous description of several precision measurements is difficult in the framework of a
single model
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⦁ 1.9 million positrons
1.2 TeV Dark Matter + Collision of Cosmic Rays
The positron flux appears to be in agreement with predictions
from a 1.2 TeV Dark Matter model (J. Kopp, Phys. Rev. D 88, 076013 (2013))
(e+ + e–) AMS data: comparison with other detectors
Measuring (e++e–) is much less sensitive to detect the source term due to the large e– background
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(e+ + e–) AMS data: comparison with other detectors
The Antiproton Flux is ~10-4 of the Proton Flux. A percentage precision experiment requires background rejection
close to 1 in a million
Kinetic energy [GeV]
An
tip
roto
n / p
roto
n r
ati
o
Donato et al.,
PRL 102, 071301 (2009)
Dark matter
10-4
10-5
10-6
10-7
10-3
10-2
1 10 100 1000
Dark matter + Collision of
cosmic rays
with ISM
Antiprotons in Cosmic rays
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p
e
p
175<|R|<211 GV
χ2/d.f. = 138/154
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Antiproton measurement with AMS
Signal identification from 2D template fit in (∧TRD - ∧CC ) plane
p 3.49105 events
• AMS-02
o PAMELA
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Antiproton-to-Proton Flux Ratio
M. Aguilar et al. Phys. Rev. Lett. 117 (2016) 091103
Show no rigidity dependence above 60 GV
G.Giesen, et. al., JCAP 09 (2015) 023
C.Evoli et. al., JCAP 12 (2015) 039
R.Kappl, et. al., JACP 10(2015) 034
Collision of cosmic rays with interstellar medium:
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Primary and secondary cosmic ray
08/07/2014 23
PDG, Phys. Rev. D86, 010001 (2012)
A. Obermeier et al. Astrophys. J. 742 (2011) 14
Understanding the origin, acceleration and propagation of CR require the
knowledge of the chemical composition over a wide energy range
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Primary and secondary Cosmic Rays Comparison with earlier measurements
M. Aguilar et al. Phys. Rev. Lett. 120 (2018) 021101 M. Aguilar et al. Phys. Rev. Lett. 119 (2017) 251101
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Primary and secondary Cosmic Rays with AMS
Secondary/Primary Flux Ratios = KRΔ
Combining the six ratios,
the secondary over primary flux ratio (B/C, …),
deviates from single power law above 200 GV by 0.13±0.03
Δ[200-3300GV] – Δ[60-200GV] = 0.13±0.03
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0 G
V
20
0 G
V
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[GV]R~
Rigidity
3 4 5 10 20 210 210´23
103
10´2
] 1.7
GV
-1s
r-1
s-2
[ m
2.7
R´
NF
5
10
15
20
25
a) AMS
SNF+P
NF=NF
BF´= 0.62S
NF; OF´= 0.09PNF
Primary Component
Secondary Component
Nitrogen Cosmic Rays
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AMS
ΦN = ΦNP+ΦN
S
ΦN = ΦNP+ΦN
S = (0.090±0.002)×ΦO+(0.62±0.02)×ΦB
M. Aguilar et al. Phys. Rev. Lett. 121 (2018) 051103
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3He/4He abundancies
Preliminary data, refer to upcoming AMS PRL publication
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AMS continous measurement of the e+ and e- flux in the energy range 1 -50 GeV
over 6 years with a time resolution of 27 days.
M. Aguilar et al. Phys. Rev. Lett. 121 (2018) 051102
Anti Deuterons have been proposed as an almost background free channel for Dark Matter indirect detection
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Anti Deuterons in Cosmic rays
The Anti Deuterons Flux is < 10-4 of the Antiproton Flux. Additional background rejection
1 4 10 40 100
10-6
10-8
10-10
Rigidity [GV]
Flu
x [
(m2 s
r s
GV
)-1]
D from collisions of
ordinary cosmic rays
D from annihilation
of Dark Matter
Dark Matter model: F. Donato et al., Phys. Rev. D, 62 (2000) 043003
Collisions of CR model K. Blum et al., Phys. Rev. D 96 (2017) 103021)
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Anti-deuterons have never been observed in space
BESS results (COSPAR 2018)
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Anti-Deuteron Search with AMS
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Anti-Deuteron Search prospects
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Y
Z
X
First anti-Helium event in the cosmos:
Momentum = 33.1 ± 1.6 GeV/c Charge = -1.97 ± 0.05 Mass = 2.93 ± 0.36 GeV/c2
Mass (3He) = 2.83 GeV/c 2
Date: 2011-269:11:19:32
Anti-Helium Search with AMS
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3He flux models from collisions of cosmic rays
There are large uncertainties in models to ascertain the origin of 3He The rate of anti-helium is ~1 in 100 million helium.
We have also observed two 4He candidates. More events are necessary to ensure that there are no backgrounds.
Kinetic Energy/nucleon
model variations factor of ~300
K. Blum et al., Phys. Rev. D 96, 103021 (2017)
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High precision measurements of cosmic rays open new windows to observe unexpected phenomena
There are several large scale detectors in space to study high energy charged cosmic rays:
AMS, CALET, DAMPE, ISS-CREAM exploring a new and exciting frontier in physics research
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