Cosmic Rays: AMS Experiment Javier Berdugo (CIEMAT, Madrid) October - PowerPoint PPT Presentation

Cosmic Rays: AMS Experiment Javier Berdugo (CIEMAT, Madrid) October 11 th 2018 Frontiers of Astroparticle Physics. La Palma

Cosmic rays 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 P. Mertsch arXiv: 1012.4239 [astro-ph.HE] Sci. Amer. 276 (1997) 44 2

Antiparticles in Cosmic Rays and Dark Matter The collision of cosmic rays with interstellar medium (ISM) produces antiparticles (e + , p, D, …) p, He + ISM  antiparticles + …          p, He EARTH ISM antiparticles The collision of dark matter particles will produce additional antiparticles  +   antiparticles + … 3

Positrons in Cosmic Rays e + /(e + + e - ) m  =800 GeV m  =400 GeV I. Cholis et al., arXiv:0810.5344 e ± energy [GeV] 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; 4 M. Pato, M. Lattanzi and G. Bertone, JCAP 1012 (2010) 020.

Flux of antiparticles in cosmic rays Precision measurements of antiparticles requires long exposure time with detectors with large acceptance and percent level precision. Experiments operating outside the atmosphere and capable to measure simultaneously the spectra of the different cosmic ray components. 5

Space based cosmic ray experiments O. Adriani et al. Nature 458 (2009) PAMELA: Launched on June 15 th 2006 Baikonur Cosmodrome (Kazakhstan) Image: http://wizard.roma2.infn.it/pamela/html/resurs.html M. Ackerman et al. Phys. Rev. Lett. 108 (2012) 011103 FERMI Launched on June 11, 2008 6 Image credit: NASA/Jerry Cannon, Robert Murray

Space-born Cosmic Ray Experiments in operation AMS, started May 2011 CALET, started August 2015 DAMPE, started December 2015 ISS CREAM, started August 2017 7 7

5m x 4m x 3m 7.5 tons Silicon layer TRD 1 TOF 1, 2 Magnet Silicon layers and 2 - 8 Veto Counters TOF 3, 4 RICH Silicon layer 9 ECAL Acceptance: 0.5 m 2 sr 08/07/2014 8

AMS is an international collaboration based at CERN FINLAND UNIV. OF TURKU RUSSIA NETHERLANDS ITEP ESA-ESTEC KURCHATOV INST. GERMANY NIKHEF FRANCE RWTH-I. Aachen LUPM MONTPELLIER KIT-KARLSRUHE KOREA LAPP ANNECY LPSC GRENOBLE CER EWHA MIT USA N= KYUNGPOOK NAT.UNIV. CHINA TURKEY DOE- CALT (Beijing) NASA IEE (Beijing) METU, ANKARA JSC IHEP (Beijing) SWITZERLAND NLAA (Beijing) BUAA(Beijing) ETH-ZURICH PORTUGAL UNIV. OF GENEVA SJTU (Shanghai) MEXICO LAB. OF INSTRUM. LISBON SEU (Nanjing) UNAM SYSU (Guangzhou) ITALY SDU (Jinan) ASI IROE FLORENCE TAIWAN SPAIN INFN & UNIV. OF BOLOGNA ACAD. SINICA (Taipei) CIEMAT - MADRID INFN & UNIV. OF MILANO-BICOCCA CSIST (Taipei) I.A.C. CANARIAS. INFN & UNIV. OF PERUGIA NCU (Chung Li) INFN & UNIV. OF PISA NCKU (Tainan) INFN & UNIV. OF ROMA BRAZIL INFN & UNIV. OF TRENTO IFSC – SÃO CARLOS INSTITUTE OF PHYSICS 9 It took 650 physicists and engineers 17 years to construct AMS 9

Ground Tests and Calibrations Space Qualification (EMI and TV at ESTEC) TVT Chamber: P < 10 -9 bar Ambient temperature: -90 o C to 40 o C Test Beam at CERN (Calibration) 1,762 positions and angles with p, e + , e − , pion beams from 10 to 400 GeV/c 10 10

Positron measurement with AMS Signal identification from 2D template fit in ( ∧ TRD - ∧ CC ) plane 237<|R|<290 GV 11

Positron fraction in cosmic rays with AMS 12

Latest AMS results on positron and electron fluxes Energy range from 0.5 GeV to 1 TeV 250 25 ] ] 2 2 GeV 28.1 million electrons GeV -1 -1 200 20 sr sr -1 -1 s s -2 -2 [m [m 150 15 3 3 E E - + e e F F 100 10 1.9 million positrons 50 5 Energy [GeV] 0 0 1 10 100 1000 13

AMS Positron cosmic ray anisotropy Astrophysical point sources like pulsars will imprint a higher anisotropy on the arrival directions of energetic positrons than a smooth dark matter halo. The anisotropy in galactic coordinates C 1 is the dipole moment positrons Isotropic Map Amplitude of the dipole anisotropy on positrons for 16 < E < 350 GeV δ < 0.019 (95% C.I.) 14

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 Models based on very different assumptions describe observed trends of a single measurement. Simultaneous description of several precision measurements is difficult in the framework of a single model 15

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) ) ⦁ 1.9 million positrons 1.2 TeV Dark Matter + Collision of Cosmic Rays 16

(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 17

(e + + e – ) AMS data: comparison with other detectors 18

Antiprotons in Cosmic rays 10 -2 Dark matter + Antiproton / proton ratio Collision of 10 -3 cosmic rays with ISM Dark matter 10 -4 10 -5 10 -6 Donato et al., Kinetic energy [GeV] PRL 102, 071301 (2009) 10 -7 1 10 1000 100 The Antiproton Flux is ~10 -4 of the Proton Flux. A percentage precision experiment requires background rejection close to 1 in a million 19

Antiproton measurement with AMS Signal identification from 2D template fit in ( ∧ TRD - ∧ CC ) plane 175<|R|<211 GV p e χ2 /d.f. = 138/154 p 20

Antiproton-to-Proton Flux Ratio Show no rigidity dependence above 60 GV M. Aguilar et al. Phys. Rev. Lett. 117 (2016) 091103 p 3.49  10 5 events • AMS-02 o PAMELA 21

Collision of cosmic rays with interstellar medium: G.Giesen, et. al., JCAP 09 (2015) 023 R.Kappl, et. al., JACP 10(2015) 034 C.Evoli et. al., JCAP 12 (2015) 039 22

Primary and secondary cosmic ray Understanding the origin, acceleration and propagation of CR require the knowledge of the chemical composition over a wide energy range PDG, Phys. Rev. D86, 010001 (2012) A. Obermeier et al. Astrophys. J. 742 (2011) 14 08/07/2014 23

Primary and secondary Cosmic Rays Comparison with earlier measurements M. Aguilar et al. Phys. Rev. Lett. 119 (2017) 251101 M. Aguilar et al. Phys. Rev. Lett. 120 (2018) 021101 24 24

Primary and secondary Cosmic Rays with AMS 25

Secondary/Primary Flux Ratios = KR Δ 200 GV 200 GV 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 26

Nitrogen Cosmic Rays M. Aguilar et al. Phys. Rev. Lett. 121 (2018) 051103 Φ N = Φ NP + Φ NS = ( 0.090±0.002 ) ×Φ O + ( 0.62±0.02 ) ×Φ B 25 AMS AMS a) F F F S P ] Φ N = Φ NP + Φ NS = + N N N 1.7 20 F ´ F F S ´ F P = 0.09 ; = 0.62 GV N O N B -1 sr 15 -1 s -2 [ m Secondary Component 10 2.7 R ´ 5 N F Primary Component ~ Rigidity R [GV] ´ 3 ´ 3 2 2 27 3 4 5 10 20 10 2 10 10 2 10 27

3 He/ 4 He abundancies Preliminary data, refer to upcoming AMS PRL publication 28

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 29

Anti Deuterons in Cosmic rays Anti Deuterons have been proposed as an almost background free channel for Dark Matter indirect detection D from annihilation of Dark Matter Flux [(m 2 sr s GV) -1 ] D from collisions of 10 -6 ordinary cosmic rays 10 -8 10 -10 Rigidity [GV] 1 4 10 40 100  Dark Matter model:  Collisions of CR model K. Blum et al., Phys. Rev. D 96 (2017) 103021) F. Donato et al., Phys. Rev. D, 62 (2000) 043003 The Anti Deuterons Flux is < 10 -4 of the Antiproton Flux. Additional background rejection 30

Anti-deuterons have never been observed in space BESS results (COSPAR 2018) 31 31

Anti-Deuteron Search with AMS 32

Anti-Deuteron Search prospects 33

Anti-Helium Search with AMS Z First anti-Helium event in the cosmos: Y Momentum = 33.1 ± 1.6 GeV/ c = -1.97 ± 0.05 Charge = 2.93 ± 0.36 GeV/ c 2 Mass Mass ( 3 He) = 2.83 GeV/c 2 X Date: 2011-269:11:19:32 34

3 He flux models from collisions of cosmic rays K. Blum et al., Phys. Rev. D 96 , 103021 (2017) model variations factor of ~300 Kinetic Energy/nucleon There are large uncertainties in models to ascertain the origin of 3 He The rate of anti-helium is ~1 in 100 million helium. We have also observed two 4 He candidates. More events are necessary to ensure that there are no backgrounds. 35