1.
Phys Rev Lett
; 113(12): 121101, 2014 Sep 19.
Artículo
en Inglés
| MEDLINE
| ID: mdl-25279616
RESUMEN
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 â¼200 GeV the positron fraction no longer exhibits an increase with energy.