High statistics measurement of the positron fraction in primary cosmic rays of 0.5-500 GeV with the alpha magnetic spectrometer on the international space station

L Accardo; M Aguilar; D Aisa; B Alpat; A Alvino; G Ambrosi; K Andeen; L Arruda; N Attig; P Azzarello; A Bachlechner; F Barao; A Barrau; L Barrin; A Bartoloni; L Basara; M Battarbee; R Battiston; J Bazo; U Becker; M Behlmann; B Beischer; J Berdugo; B Bertucci; G Bigongiari; V Bindi; S Bizzaglia; M Bizzarri; G Boella; W de Boer; K Bollweg; V Bonnivard; B Borgia; S Borsini; M J Boschini; M Bourquin; J Burger; F Cadoux; X D Cai; M Capell; S Caroff; G Carosi; J Casaus; V Cascioli; G Castellini; I Cernuda; D Cerreta; F Cervelli; M J Chae; Y H Chang; A I Chen; H Chen; G M Cheng; H S Chen; L Cheng; A Chikanian; H Y Chou; E Choumilov; V Choutko; C H Chung; F Cindolo; C Clark; R Clavero; G Coignet; C Consolandi; A Contin; C Corti; B Coste; Z Cui; M Dai; C Delgado; S Della Torre; M B Demirköz; L Derome; S Di Falco; L Di Masso; F Dimiccoli; C Díaz; P von Doetinchem; W J Du; M Duranti; D D'Urso; A Eline; F J Eppling; T Eronen; Y Y Fan; L Farnesini; J Feng; E Fiandrini; A Fiasson; E Finch; P Fisher; Y Galaktionov; G Gallucci; B García; R García-López; H Gast; I Gebauer; M Gervasi; A Ghelfi; W Gillard; F Giovacchini; P Goglov; J Gong; C Goy; V Grabski; D Grandi; M Graziani; C Guandalini; I Guerri; K H Guo; D Haas; M Habiby; S Haino; K C Han; Z H He; M Heil; R Henning; J Hoffman; T H Hsieh; Z C Huang; C Huh; M Incagli; M Ionica; W Y Jang; H Jinchi; K Kanishev; G N Kim; K S Kim; Th Kirn; R Kossakowski; O Kounina; A Kounine; V Koutsenko; M S Krafczyk; S Kunz; G La Vacca; E Laudi; G Laurenti; I Lazzizzera; A Lebedev; H T Lee; S C Lee; C Leluc; G Levi; H L Li; J Q Li; Q Li; Q Li; T X Li; W Li; Y Li; Z H Li; Z Y Li; S Lim; C H Lin; P Lipari; T Lippert; D Liu; H Liu; M Lolli; T Lomtadze; M J Lu; Y S Lu; K Luebelsmeyer; F Luo; J Z Luo; S S Lv; R Majka; A Malinin; C Mañá; J Marín; T Martin; G Martínez; N Masi; F Massera; D Maurin; A Menchaca-Rocha; Q Meng; D C Mo; B Monreal; L Morescalchi; P Mott; M Müller; J Q Ni; N Nikonov; F Nozzoli; P Nunes; A Obermeier; A Oliva; M Orcinha; F Palmonari; C Palomares; M Paniccia; A Papi; M Pauluzzi; E Pedreschi; S Pensotti; R Pereira; R Pilastrini; F Pilo; A Piluso; C Pizzolotto; V Plyaskin; M Pohl; V Poireau; E Postaci; A Putze; L Quadrani; X M Qi; P G Rancoita; D Rapin; J S Ricol; I Rodríguez; S Rosier-Lees; L Rossi; A Rozhkov; D Rozza; G Rybka; R Sagdeev; J Sandweiss; P Saouter; C Sbarra; S Schael; S M Schmidt; D Schuckardt; A Schulz von Dratzig; G Schwering; G Scolieri; E S Seo; B S Shan; Y H Shan; J Y Shi; X Y Shi; Y M Shi; T Siedenburg; D Son; F Spada; F Spinella; W Sun; W H Sun; M Tacconi; C P Tang; X W Tang; Z C Tang; L Tao; D Tescaro; Samuel C C Ting; S M Ting; N Tomassetti; J Torsti; C Türkoğlu; T Urban; V Vagelli; E Valente; C Vannini; E Valtonen; S Vaurynovich; M Vecchi; M Velasco; J P Vialle; V Vitale; G Volpini; L Q Wang; Q L Wang; R S Wang; X Wang; Z X Wang; Z L Weng; K Whitman; J Wienkenhöver; H Wu; K Y Wu; X Xia; M Xie; S Xie; R Q Xiong; G M Xin; N S Xu; W Xu; Q Yan; J Yang; M Yang; Q H Ye; H Yi; Y J Yu; Z Q Yu; S Zeissler; J H Zhang; M T Zhang; X B Zhang; Z Zhang; Z M Zheng; F Zhou; H L Zhuang; V Zhukov; A Zichichi; N Zimmermann; P Zuccon; C Zurbach; AMS Collaboration

doi:10.1103/PhysRevLett.113.121101

High statistics measurement of the positron fraction in primary cosmic rays of 0.5-500 GeV with the alpha magnetic spectrometer on the international space station

Phys Rev Lett. 2014 Sep 19;113(12):121101. doi: 10.1103/PhysRevLett.113.121101. Epub 2014 Sep 18.

Authors

L Accardo¹, M Aguilar², D Aisa³, B Alpat¹, A Alvino¹, G Ambrosi¹, K Andeen⁴, L Arruda⁵, N Attig⁶, P Azzarello⁷, A Bachlechner⁸, F Barao⁵, A Barrau⁹, L Barrin¹⁰, A Bartoloni¹¹, L Basara¹², M Battarbee¹³, R Battiston¹⁴, J Bazo¹, U Becker¹⁵, M Behlmann¹⁵, B Beischer⁸, J Berdugo², B Bertucci³, G Bigongiari¹⁶, V Bindi¹⁷, S Bizzaglia¹, M Bizzarri³, G Boella¹⁸, W de Boer⁴, K Bollweg¹⁹, V Bonnivard⁹, B Borgia²⁰, S Borsini¹, M J Boschini²¹, M Bourquin²², J Burger¹⁵, F Cadoux²², X D Cai¹⁵, M Capell¹⁵, S Caroff²³, G Carosi¹⁵, J Casaus², V Cascioli¹, G Castellini²⁴, I Cernuda², D Cerreta³, F Cervelli²⁵, M J Chae²⁶, Y H Chang²⁷, A I Chen¹⁵, H Chen¹⁵, G M Cheng²⁸, H S Chen²⁸, L Cheng²⁹, A Chikanian³⁰, H Y Chou²⁷, E Choumilov¹⁵, V Choutko¹⁵, C H Chung⁸, F Cindolo³¹, C Clark¹⁹, R Clavero³², G Coignet²³, C Consolandi¹⁷, A Contin³¹, C Corti¹⁷, B Coste¹⁴, Z Cui²⁹, M Dai³³, C Delgado², S Della Torre²¹, M B Demirköz³⁴, L Derome⁹, S Di Falco²⁵, L Di Masso³, F Dimiccoli¹⁴, C Díaz², P von Doetinchem¹⁷, W J Du²⁹, M Duranti¹, D D'Urso¹, A Eline¹⁵, F J Eppling¹⁵, T Eronen¹³, Y Y Fan³⁵, L Farnesini¹, J Feng²³, E Fiandrini³, A Fiasson²³, E Finch³⁰, P Fisher¹⁵, Y Galaktionov¹⁵, G Gallucci³⁶, B García², R García-López³², H Gast⁸, I Gebauer⁴, M Gervasi¹⁸, A Ghelfi⁹, W Gillard²⁷, F Giovacchini², P Goglov¹⁵, J Gong³⁷, C Goy²³, V Grabski³⁸, D Grandi²¹, M Graziani³⁹, C Guandalini³¹, I Guerri¹⁶, K H Guo⁴⁰, D Haas²², M Habiby²², S Haino⁴¹, K C Han⁴², Z H He⁴⁰, M Heil⁴³, R Henning¹⁵, J Hoffman²⁷, T H Hsieh¹⁵, Z C Huang⁴⁰, C Huh⁴⁴, M Incagli²⁵, M Ionica¹, W Y Jang⁴⁴, H Jinchi⁴², K Kanishev¹⁴, G N Kim⁴⁴, K S Kim⁴⁴, Th Kirn⁸, R Kossakowski²³, O Kounina¹⁵, A Kounine¹⁵, V Koutsenko¹⁵, M S Krafczyk¹⁵, S Kunz⁴, G La Vacca⁴⁵, E Laudi³, G Laurenti³¹, I Lazzizzera¹⁴, A Lebedev¹⁵, H T Lee³⁵, S C Lee³⁵, C Leluc²², G Levi³¹, H L Li³⁵, J Q Li³⁷, Q Li³⁷, Q Li¹⁵, T X Li⁴⁰, W Li⁴⁶, Y Li²², Z H Li²⁸, Z Y Li³⁵, S Lim²⁶, C H Lin³⁵, P Lipari¹¹, T Lippert⁶, D Liu³⁵, H Liu³⁷, M Lolli³¹, T Lomtadze²⁵, M J Lu¹⁴, Y S Lu²⁸, K Luebelsmeyer⁸, F Luo²⁹, J Z Luo³⁷, S S Lv⁴⁰, R Majka³⁰, A Malinin⁴⁷, C Mañá², J Marín², T Martin¹⁹, G Martínez², N Masi³¹, F Massera³¹, D Maurin⁹, A Menchaca-Rocha³⁸, Q Meng³⁷, D C Mo⁴⁰, B Monreal¹⁵, L Morescalchi²⁵, P Mott¹⁹, M Müller⁸, J Q Ni⁴⁰, N Nikonov⁴, F Nozzoli¹, P Nunes⁵, A Obermeier⁸, A Oliva², M Orcinha⁵, F Palmonari³¹, C Palomares², M Paniccia²², A Papi¹, M Pauluzzi³, E Pedreschi²⁵, S Pensotti¹⁸, R Pereira⁴⁸, R Pilastrini³¹, F Pilo²⁵, A Piluso³, C Pizzolotto¹, V Plyaskin¹⁵, M Pohl²², V Poireau²³, E Postaci³⁴, A Putze²³, L Quadrani³¹, X M Qi⁴⁰, P G Rancoita²¹, D Rapin²², J S Ricol⁹, I Rodríguez², S Rosier-Lees²³, L Rossi¹⁰, A Rozhkov¹⁵, D Rozza²¹, G Rybka¹⁵, R Sagdeev⁴⁹, J Sandweiss³⁰, P Saouter²², C Sbarra³¹, S Schael⁸, S M Schmidt⁶, D Schuckardt⁴, A Schulz von Dratzig⁸, G Schwering⁸, G Scolieri¹, E S Seo⁴⁷, B S Shan⁴⁶, Y H Shan⁴⁶, J Y Shi³⁷, X Y Shi¹⁵, Y M Shi⁵⁰, T Siedenburg⁸, D Son⁴⁴, F Spada¹¹, F Spinella²⁵, W Sun¹⁵, W H Sun¹⁵, M Tacconi¹⁸, C P Tang⁴⁰, X W Tang²⁸, Z C Tang²⁸, L Tao²³, D Tescaro³², Samuel C C Ting¹⁵, S M Ting¹⁵, N Tomassetti⁹, J Torsti¹³, C Türkoğlu³⁴, T Urban¹⁹, V Vagelli⁴, E Valente²⁰, C Vannini²⁵, E Valtonen¹³, S Vaurynovich¹⁵, M Vecchi²³, M Velasco², J P Vialle²³, V Vitale¹, G Volpini⁵¹, L Q Wang²⁹, Q L Wang³³, R S Wang⁵⁰, X Wang¹⁵, Z X Wang⁴⁰, Z L Weng¹⁵, K Whitman¹⁷, J Wienkenhöver⁸, H Wu³⁷, K Y Wu³⁵, X Xia², M Xie¹⁵, S Xie⁵⁰, R Q Xiong³⁷, G M Xin²⁹, N S Xu⁴⁰, W Xu⁵², Q Yan²⁸, J Yang²⁶, M Yang²⁸, Q H Ye⁵⁰, H Yi³⁷, Y J Yu³³, Z Q Yu²⁸, S Zeissler⁴, J H Zhang³⁷, M T Zhang⁴⁰, X B Zhang⁴⁰, Z Zhang⁴⁰, Z M Zheng⁴⁶, F Zhou¹⁵, H L Zhuang²⁸, V Zhukov⁸, A Zichichi³¹, N Zimmermann⁸, P Zuccon¹⁵, C Zurbach⁵³; AMS Collaboration

Affiliations

¹ INFN-Sezione di Perugia, I-06100 Perugia, Italyx.
² Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas, CIEMAT, E-28040 Madrid, SpainC.
³ INFN-Sezione di Perugia, I-06100 Perugia, Italyx and Università di Perugia, I-06100 Perugia, Italy.
⁴ Institut für Experimentelle Kernphysik, Karlsruhe Institute of Technology, KIT, D-76128 Karlsruhe, GermanyB.
⁵ Laboratório de Instrumentação e Física Experimental de Partículas, LIP, P-1000 Lisboa, Portugal.
⁶ Jülich Supercomputing Centre and JARA-FAME, Research Centre Jülich, D-52425 Jülich, GermanyA.
⁷ DPNC, Université de Genève, CH-1211 Genève 4, Switzerland and INFN-Sezione di Perugia, I-06100 Perugia, Italyx.
⁸ I. Physics Institute and JARA-FAME, RWTH Aachen University, D-52056 Aachen, Germanyu.
⁹ Laboratoire de Physique Subatomique et de Cosmologie, LPSC, Université Grenoble-Alpes, CNRS/IN2P3, F-38026 Grenoble, France.
¹⁰ European Organization for Nuclear Research, CERN, CH-1211 Geneva 23, Switzerland.
¹¹ INFN-Sezione di Roma 1, I-00185 Roma, Italyx.
¹² Laboratoire d'Annecy-Le-Vieux de Physique des Particules, LAPP, IN2P3/CNRS and Université de Savoie, F-74941 Annecy-le-Vieux, France and INFN-TIFPA and Università di Trento, I-38123 Povo, Trento, Italyx.
¹³ Space Research Laboratory, Department of Physics and Astronomy, University of Turku, FI-20014 Turku, Finland.
¹⁴ INFN-TIFPA and Università di Trento, I-38123 Povo, Trento, Italyx.
¹⁵ Massachusetts Institute of Technology, MIT, Cambridge, Massachusetts 02139, USA.
¹⁶ INFN-Sezione di Pisa, I-56100 Pisa, Italyx and Università di Pisa, I-56100 Pisa, Italy.
¹⁷ Physics and Astronomy Department, University of Hawaii, 2505 Correa Road, WAT 432, Honolulu, Hawaii 96822, USA.
¹⁸ INFN-Sezione di Milano-Bicocca, I-20126 Milano, Italyx and Università di Milano-Bicocca, I-20126 Milano, Italy.
¹⁹ NASA, National Aeronautics and Space Administration, Johnson Space Center, JSC, and Jacobs-Sverdrup, Houston, Texas 77058, USA.
²⁰ INFN-Sezione di Roma 1, I-00185 Roma, Italyx and Università di Roma La Sapienza, I-00185 Roma, Italy.
²¹ INFN-Sezione di Milano-Bicocca, I-20126 Milano, Italyx.
²² DPNC, Université de Genève, CH-1211 Genève 4, Switzerland.
²³ Laboratoire d'Annecy-Le-Vieux de Physique des Particules, LAPP, IN2P3/CNRS and Université de Savoie, F-74941 Annecy-le-Vieux, France.
²⁴ CNR-IROE, I-50125 Firenze, Italy.
²⁵ INFN-Sezione di Pisa, I-56100 Pisa, Italyx.
²⁶ Department of Physics, Ewha Womans University, Seoul 120-750, KoreaE.
²⁷ National Central University, NCU, Chung-Li, Tao Yuan 32054, Taiwany.
²⁸ Institute of High Energy Physics, IHEP, Chinese Academy of Sciences, Beijing 100039, Chinaw.
²⁹ Shandong University, SDU, Jinan, Shandong 250100, China.
³⁰ Physics Department, Yale University, New Haven, Connecticut 06520, USA.
³¹ INFN-Sezione di Bologna, I-40126 Bologna, Italyx and Università di Bologna, I-40126 Bologna, Italy.
³² Instituto de Astrofísica de Canarias, IAC, E-38205 La Laguna, Tenerife, Spain.
³³ Institute of Electrical Engineering, IEE, Chinese Academy of Sciences, Beijing 100080, China.
³⁴ Department of Physics, Middle East Technical University, METU, 06800 Ankara, Turkeyv.
³⁵ Institute of Physics, Academia Sinica, Nankang, Taipei 11529, Taiwany.
³⁶ European Organization for Nuclear Research, CERN, CH-1211 Geneva 23, Switzerland and INFN-Sezione di Pisa, I-56100 Pisa, Italyx.
³⁷ Southeast University, SEU, Nanjing 210096, China.
³⁸ Instituto de Física, Universidad Nacional Autónoma de México, UNAM, México D.F. 01000, MéxicoD.
³⁹ European Organization for Nuclear Research, CERN, CH-1211 Geneva 23, Switzerland and INFN-Sezione di Perugia, I-06100 Perugia, Italyx.
⁴⁰ Sun Yat-Sen University, SYSU, Guangzhou 510275, China.
⁴¹ National Central University, NCU, Chung-Li, Tao Yuan 32054, Taiwany and Institute of Physics, Academia Sinica, Nankang, Taipei 11529, Taiwany.
⁴² National Chung-Shan Institute of Science and Technology, NCSIST, Longtan, Tao Yuan 325, Taiwan.
⁴³ Massachusetts Institute of Technology, MIT, Cambridge, Massachusetts 02139, USA and Institut für Experimentelle Kernphysik, Karlsruhe Institute of Technology, KIT, D-76128 Karlsruhe, GermanyB.
⁴⁴ CHEP, Kyungpook National University, 702-701 Daegu, Koreaz.
⁴⁵ European Organization for Nuclear Research, CERN, CH-1211 Geneva 23, Switzerland and INFN-Sezione di Milano-Bicocca, I-20126 Milano, Italyx.
⁴⁶ Beihang University, BUAA, Beijing 100191, China.
⁴⁷ IPST, University of Maryland, College Park, Maryland 20742, USA.
⁴⁸ Physics and Astronomy Department, University of Hawaii, 2505 Correa Road, WAT 432, Honolulu, Hawaii 96822, USA and Laboratório de Instrumentação e Física Experimental de Partículas, LIP, P-1000 Lisboa, Portugal.
⁴⁹ East-West Center for Space Science, University of Maryland, College Park, Maryland 20742, USA.
⁵⁰ Shanghai Jiaotong University, SJTU, Shanghai 200030, China.
⁵¹ INFN-Sezione di Milano and Università di Milano, I-20090 Milano, Italy.
⁵² Institute of High Energy Physics, IHEP, Chinese Academy of Sciences, Beijing 100039, Chinaw and Massachusetts Institute of Technology, MIT, Cambridge, Massachusetts 02139, USA.
⁵³ Laboratoire Univers et Particules de Montpellier, LUPM, IN2P3/CNRS and Université de Montpellier II, F-34095 Montpellier, France.

PMID: 25279616
DOI: 10.1103/PhysRevLett.113.121101

Abstract

A precision measurement by AMS of the positron fraction in primary cosmic rays in the energy range from 0.5 to 500 GeV based on 10.9 million positron and electron events is presented. This measurement extends the energy range of our previous observation and increases its precision. The new results show, for the first time, that above ∼200 GeV the positron fraction no longer exhibits an increase with energy.