Latest results of the AMS Experiment NCTS Annual

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Latest results of the AMS Experiment NCTS Annual Theory Meeting NCTS, Dec. 06, 2016

Latest results of the AMS Experiment NCTS Annual Theory Meeting NCTS, Dec. 06, 2016 Yuan-Hann Chang National Central University

Special colloquium by AMS spokesman Samuel Ting Thursday, Dec. 8, 2016, 17: 00 -18:

Special colloquium by AMS spokesman Samuel Ting Thursday, Dec. 8, 2016, 17: 00 -18: 00 at CERN (Midnight in Taiwan) “The First Five Years of the Alpha Magnetic Spectrometer on the International Space Station” Webcast available

AMS is a space-borne magnetic spectrometer which measures the ridigidty, energy, charge and velocity

AMS is a space-borne magnetic spectrometer which measures the ridigidty, energy, charge and velocity of cosmic ray particles precisely 1 TRD ransition Raditaion detector Time-of-Flight Counter TOF 2 3 -4 Tracker 5 -6 7 -8 TOF Silicon Tracker RICH Magnet 9 ECA L /3 Electromagnetic Ring-Image Cerenkov detector

AMS was launched to the ISS by Shuttle Endeavor on May 16, 2011 4

AMS was launched to the ISS by Shuttle Endeavor on May 16, 2011 4

AMS Research In 5 years on ISS, AMS has collected >85 billion charged cosmic

AMS Research In 5 years on ISS, AMS has collected >85 billion charged cosmic rays. It is a very precise particle physics detector. The data was analysed by at least two independent international teams 5

I. Search for Dark Matter • Positron fraction • Electron and positron spectrum •

I. Search for Dark Matter • Positron fraction • Electron and positron spectrum • Antiproton to proton ratio

Search for the Dark Matter through its annihilation product: Positrons and Antiprotons in the

Search for the Dark Matter through its annihilation product: Positrons and Antiprotons in the cosmic rays.

Collision of “ordinary” Cosmic Rays produce e+, p… Annihilation of Dark Matter (neutralinos, )

Collision of “ordinary” Cosmic Rays produce e+, p… Annihilation of Dark Matter (neutralinos, ) will produce additional e+, p + e+ + … M. Turner and F. Wilczek, Phys. Rev. D 42 (1990) 1001 Physics Result 1: Measurement of the Positron Fraction 6. 8 million e+, e− events AMS-02 data on ISS 6. 8 million e± events, PRL 110, 141102 (2013) m =800 Ge. V The excess of positrons is measured by the positron fraction: e+/(e+ + e−) s odel Dark er M Matt m =400 Ge. V 0. 1 Collision o f Cosmic R ays Dark Matter model based on I. Cholis et al. , ar. Xiv: 0810. 5344 10 Energy (Ge. V) 102 PRL 110, 141102 (2013) 8

Results on the Positron Fraction from 11 million e± Editor’s Suggestion III. The energy

Results on the Positron Fraction from 11 million e± Editor’s Suggestion III. The energy beyond which it ceases to increase. e+ /(e+ + e-) II. The rate of increase with energy compared with models + + + … e m =800 Ge. V IV. Anisotropy m =400 Ge. V I. The energy at which it begins to increase. e +, e - from Collision o f Cosmic Ra ys V. The rate at which it falls beyond the turning point. e± energy [Ge. V] 9

I. The energy at which it begins to increase 10

I. The energy at which it begins to increase 10

(ii)The rate of increase with energy. non-existence of sharp structures.

(ii)The rate of increase with energy. non-existence of sharp structures.

III. The energy beyond which it ceases to increase 12

III. The energy beyond which it ceases to increase 12

Positron fraction V. The 2024 data beyond the Maximum. MC simulation Data by 2024

Positron fraction V. The 2024 data beyond the Maximum. MC simulation Data by 2024 Pulsars Maximum 265± 22 Ge. V M = 1 Te. V Collision of cosmic rays I. Cholis and D. Hooper, Phys. Rev. D 88 (2013) 023013 J. Kopp, Phys. Rev. D 88 (2013) 076013 e± energy [Ge. V] 13

Latest result based on 20 million e+, e- events Positron Fraction Comparison with theoretical

Latest result based on 20 million e+, e- events Positron Fraction Comparison with theoretical Models AMS 2016 M = 1 Te. V Collis ion of Cosm ic Ray s Model based on J. Kopp, Phys. Rev. D 88 (2013) 076013 e± energy [Ge. V] 14

Significance IV. The anisotropy The fluctuations of the positron ratio e+/e− are isotropic. Galactic

Significance IV. The anisotropy The fluctuations of the positron ratio e+/e− are isotropic. Galactic coordinates (b, l) The anisotropy in galactic coordinates C 1 is the dipole moment Current value (d) Anisotropy of e+/e- Pulsars Isotropy Anisotropy on e+/e- : Projected dipole measurement Pulsar Model : D. Hooper, P. Blasi & P. D. Serpico, JCAP 0901(2009) Data taking to 2024, will allow to explore anisotropies of 1% 15

The Electron and Positron fluxes Φ=CE = 9, 200, 000 Positron Spectrum Electron Spectrum

The Electron and Positron fluxes Φ=CE = 9, 200, 000 Positron Spectrum Electron Spectrum Based on 0. 6 million positron events 600, 000 The electron flux also shows excess above 50 Ge. V. The rise of positron fraction is due to excess of positron, not deficit of electron. 16

Latest results based on 1. 08 million positron events Positron Spectrum AMS 2016 1,

Latest results based on 1. 08 million positron events Positron Spectrum AMS 2016 1, 080, 000 Positrons 17

The antiproton flux and properties of elementary particle fluxes • AMS Dark matter Collisions

The antiproton flux and properties of elementary particle fluxes • AMS Dark matter Collisions of ordina ry cosmic ra y s Models from Donato et al. , PRL 102, 071301 ( 2009 ); mχ = 1 Te. V Antiproton is a complementary probe, it cannot be produced in astrophysical origin like pulsars. A constant p/p ratio is surprising. 18

Unexpected Result: The Spectra of Elementary Particles e+, p, p have identical energy dependence

Unexpected Result: The Spectra of Elementary Particles e+, p, p have identical energy dependence above 60 Ge. V e- does not. A challenge to theory/model: positron and antiproton are secondary cosmic rays with very different production and propagation properties. p p e+ e− 3 x 103 20 19

II. Unveiling the origin and propagation of Cosmic Rays • • e+ + e

II. Unveiling the origin and propagation of Cosmic Rays • • e+ + e Proton Helium Boron Carbon Lithium And their ratios.

e contribution from Astrophysics processes before assessing tributions. d predict not just the positron/antiproton

e contribution from Astrophysics processes before assessing tributions. d predict not just the positron/antiproton flux, but also the er elements. Understanding the cosmic ray acceleration and propagation model is a critical to resolve the mystery of positron excess. Example: R. Cowsik, B. Burch, and T. Madziwa-Nussinov, Ap. J. 786 (2014) 124 (nested leaky box model, positron comes from interstellar collisions. ) Cowsik (2014)

GALPROP program: http: //galprop. standord. edu Every flux measurement contribute to constrain the parameters.

GALPROP program: http: //galprop. standord. edu Every flux measurement contribute to constrain the parameters.

With multiple charge measurement, AMS is an ideal detector to measure the ion spectra

With multiple charge measurement, AMS is an ideal detector to measure the ion spectra in the cosmic rays H He Li C Be B N O F Ne Mg Na Al Si P S Cl Ar K Ca Sc Ti V Cr Mn Fe Ni Co 23

The (e+ + e-) flux The precision AMS measurement of the (e+ + e-)

The (e+ + e-) flux The precision AMS measurement of the (e+ + e-) flux. Energy Range: 0. 5 Ge. V to 1 Te. V 24

Spectral index of (e+ + e-) Φ(e++e−) = C E γ=− 3. 170 ±

Spectral index of (e+ + e-) Φ(e++e−) = C E γ=− 3. 170 ± 0. 008 (stat + syst. ) ± 0. 008 (energy scale) E > 30 Ge. V The (e+ + e-) flux versus the electron or positron energy and the result of a single power law fit above 30. 2 Ge. V. 25

AMS Flux The Proton proton flux • AMS-02 300 million events 26

AMS Flux The Proton proton flux • AMS-02 300 million events 26

Proton Spectrum AMS proton flux The spectrum cannot be described by a single power

Proton Spectrum AMS proton flux The spectrum cannot be described by a single power law. (tr singl ad e p itio ow na er la ssu law f mp it tio n) Single power law is ruled out at 99. 9% confidence level 27

The AMS proton spectrum is in good agreement with the Voyager measurement outside of

The AMS proton spectrum is in good agreement with the Voyager measurement outside of the Solar System when the effect of Solar modulation is properly taken into account

The. Helium helium flux AMS Flux AMS 50 million events • Helium are the

The. Helium helium flux AMS Flux AMS 50 million events • Helium are the 2 nd most abundant cosmic rays and are mostly produced in supernovas. 29

Helium Spectrum AMS Helium Flux 50 million helium nuclei singl Ruled e power law

Helium Spectrum AMS Helium Flux 50 million helium nuclei singl Ruled e power law out a t 99. 9 fit % C. L . Rigidity [GV] 30

The AMS proton/helium flux ratio Protons and helium are both “primary” cosmic rays. Their

The AMS proton/helium flux ratio Protons and helium are both “primary” cosmic rays. Their rigidity ratio has traditionally been assumed to be flat. Theoretical prediction A. E. Vladimirov, I. Moskalenko, A. Strong, et al. , Computer Phys. Comm. 182 (2011) 1156 AMS: this ratio is not flat. 31

Physics Result 8: The Boron flux 2. 3 million boron nuclei 32

Physics Result 8: The Boron flux 2. 3 million boron nuclei 32

Physics Result 9: The Carbon flux 8. 3 million carbon nuclei 33

Physics Result 9: The Carbon flux 8. 3 million carbon nuclei 33

Flux Ratios: Boron/Carbon and propagation C B Galactic Halo C, N, O, … +

Flux Ratios: Boron/Carbon and propagation C B Galactic Halo C, N, O, … + ISM B + X AMS Galactic Disk Cosmic Rays are commonly modeled as a relativistic gas diffusing through a magnetized plasma. Models of the magnetized plasma predict different behavior for B/C = k Rδ. With the Kolmogorov turbulence model δ = -1/3 is expected, while the Kraichnan theory leads to δ = -1/2. 34

Physics Result 7: The Boron-to-Carbon (B/C) flux ratio 2. 3 million boron nuclei and

Physics Result 7: The Boron-to-Carbon (B/C) flux ratio 2. 3 million boron nuclei and 8. 3 million carbon nuclei

Cows 2. 3 million boron nuclei and 8. 3 million carbon nuclei A single

Cows 2. 3 million boron nuclei and 8. 3 million carbon nuclei A single power law in favor of Kolmogorov model is unexpected. How much room is left for a pure astrophysical explanation of the excess of positron?

Simultaneous agreement between the model and the measured spectra of Proton Anti-Proton Helium Electron

Simultaneous agreement between the model and the measured spectra of Proton Anti-Proton Helium Electron Positron Li, Be, B, C, N, O, … Fe, …. provides very strong constraint to the parameters and the understanding of the Galactic environment (ISM, magnetic field, sources, etc. )

Example of systematical study of cosmic ray propagation: A. E. Vladimirov et. al. ,

Example of systematical study of cosmic ray propagation: A. E. Vladimirov et. al. , The Astrophysical Journal 752: 68 (2012)

Next steps for AMS: Precision measurement of the spectra of more elements in the

Next steps for AMS: Precision measurement of the spectra of more elements in the cosmic rays. This will provide a precise set of data to constrain the cosmic ray models. Next results: Li spectrum

Summary: • Excess in positron and antiproton strongly suggest the existence of an unknown

Summary: • Excess in positron and antiproton strongly suggest the existence of an unknown source. However, we need to know the astrophysical sources with better precision. • To correctly evaluate positron and antiprotons from astrophysical origin, a precise cosmic ray acceleration and propagation model is needed. • AMS measurements of P, He, B, C spectra already provide strong constraints to the existing cosmic ray models. • Measurements of more elements (up to Fe) is being carried out. • New effects to be explained: • The spectra indices break at ~200 Ge. V. • The unexpected p/He ratio. • Positron/antiproton/proton follows the same power law, but not electron. • Continue taking data through the lifetime of the ISS is critical to resolve some of these issues.

AMS will continue taking data through the lifetime of ISS, currently 2024. Do. E

AMS will continue taking data through the lifetime of ISS, currently 2024. Do. E AMS Review Chairman’s Report Barry C Barish October 11, 2016 AMS is a very impressive state-of-the-art particle spectrometer, operating at high efficiency on the International Space Station (ISS). AMS has now been running in a data taking mode for about five years, and has accumulated and published a tremendously impressive array of results on cosmic rays. These precision result have essentially ruled out previously published anomalies that may have indicated new physics. The AMS results on a wide range of cosmic ray yields are truly impressive and provide a very good basis for the committee to evaluate both the present results and the future physics potential of AMS. In addition, the detailed reports on AMS operations have given the committee a good picture of the needs and problems involved in successfully operating the AMS instrument on the International Space Station. … On the question of how much longer AMS should run, considering the unique nature of AMS and the low probability that a comparable instrument will operate in the foreseeable future, the committee concludes that: i) there is an obvious case to support operations through the three-year period covered by the proposal; and ii) there is a strong case for support through 2024, the currently expected operational life of the ISS. 41

Stay Tuned 42

Stay Tuned 42

Positron Fraction Slope [Ge. V-1] Zero crossing 265 ± 22 Ge. V Maximum 265

Positron Fraction Slope [Ge. V-1] Zero crossing 265 ± 22 Ge. V Maximum 265 ± 22 Ge. V e± energy [Ge. V] 43

Proton Spectrum Measurements of the proton spectrum before AMS 44

Proton Spectrum Measurements of the proton spectrum before AMS 44

Helium Spectrum Measurements of helium spectrum before AMS 1. Helium are the 2 nd

Helium Spectrum Measurements of helium spectrum before AMS 1. Helium are the 2 nd most abundant cosmic rays and are mostly produced in supernovas. 2. These were the best data before AMS. 45