A precision measurement by AMS of the positron fraction in primary cosmic rays in the energy range from 0.5 to 500GeV 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 200GeV the positron fraction no longer exhibits an increase with energy.
High Statistics Measurement of the Positron Fraction in Primary Cosmic Rays of 0.5-500GeV 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. d. 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. D. Torre;M. B. Demirkoz;L. Derome;S. D. Falco;L. D. Masso;F. Dimiccoli;C. Diaz;P. v. 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. Garcia;R. Garcia-Lopez;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;T. Kirn;R. Kossakowski;O. Kounina;A. Kounine;V. Koutsenko;M. S. Krafczyk;S. Kunz;G. L. 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. Mana;J. Marin;T. Martin;G. Martinez;N. Masi;F. Massera;D. Maurin;A. Menchaca-Rocha;Q. Meng;D. C. Mo;B. Monreal;L. Morescalchi;P. Mott;M. Muller;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. Rodriguez;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. S. von;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;S. C. C.;S. M. Ting;N. Tomassetti;J. Torsti;C. Turkoglu;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. Wienkenhover;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. - In: PHYSICAL REVIEW LETTERS. - ISSN 0031-9007. - STAMPA. - 113:12(2014), pp. 121101.1-121101.9. [10.1103/PhysRevLett.113.121101]
High Statistics Measurement of the Positron Fraction in Primary Cosmic Rays of 0.5-500GeV with the Alpha Magnetic Spectrometer on the International Space Station
CONTIN, ANDREA;LEVI, GIUSEPPE;PALMONARI, FEDERICO;QUADRANI, LUCIO;ZICHICHI, ANTONINO;
2014
Abstract
A precision measurement by AMS of the positron fraction in primary cosmic rays in the energy range from 0.5 to 500GeV 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 200GeV the positron fraction no longer exhibits an increase with energy.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.