P. G. Rancoita

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A precise measurement of the proton flux in primary cosmic rays with rigidity (momentum/charge) from 1 GV to 1.8 TV is presented based on 300 million events. Knowledge of the rigidity dependence of the proton flux is important in understanding the origin, acceleration, and propagation of cosmic rays. We present the detailed variation with rigidity of the(More)
A precision measurement by the Alpha Magnetic Spectrometer on the International Space Station of the positron fraction in primary cosmic rays in the energy range from 0.5 to 350 GeV based on 6.8 × 10(6) positron and electron events is presented. The very accurate data show that the positron fraction is steadily increasing from 10 to ∼ 250  GeV, but, from 20(More)
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(More)
We report on measurements of hadronic and leptonic cross sections and leptonic forwardbackward asymmetries performed with the L3 detector in the years 1993–95. A total luminosity of 103 pb−1 was collected at centre-of-mass energies √ s ≈ mZ and √s ≈ mZ±1.8 GeV which corresponds to 2.5 million hadronic and 245 thousand leptonic events selected. These data(More)
Knowledge of the precise rigidity dependence of the helium flux is important in understanding the origin, acceleration, and propagation of cosmic rays. A precise measurement of the helium flux in primary cosmic rays with rigidity (momentum/charge) from 1.9 GV to 3 TV based on 50 million events is presented and compared to the proton flux. The detailed(More)
Precision measurements by the Alpha Magnetic Spectrometer on the International Space Station of the primary cosmic-ray electron flux in the range 0.5 to 700 GeV and the positron flux in the range 0.5 to 500 GeV are presented. The electron flux and the positron flux each require a description beyond a single power-law spectrum. Both the electron flux and the(More)
The AMS-02 experiment confirms the excess of positrons in cosmic rays (CRs) for energy above 10 GeV with respect to the secondary production of positrons in the interstellar medium. This is interpreted as evidence of the existence of a primary source of these particles. Possible candidates are dark matter or astrophysical sources. In this work we discuss(More)
Knowledge of the rigidity dependence of the boron to carbon flux ratio (B/C) is important in understanding the propagation of cosmic rays. The precise measurement of the B/C ratio from 1.9 GV to 2.6 TV, based on 2.3 million boron and 8.3 million carbon nuclei collected by AMS during the first 5 years of operation, is presented. The detailed variation with(More)
The Alpha Magnetic Spectrometer (AMS-02) is a high energy particle physics experiment that will study cosmic rays in the ∼ 100MeV to 1TeV range and will be installed on the International Space Station (ISS) for at least 3 years. A first version of AMS-02, AMS-01, flew aboard the space shuttle Discovery from June 2 to June 12, 1998, and collected 10 cosmic(More)
M. Acciarri 25 A. Adam 43, O. Adriani 15, M. Aguilar-Benitez 24, S. Ahlen 9, J. Alcaraz 16, A. Aloisio 27, G. Alverson t~ M.G. Alviggi 27, G. Ambrosi 32, Q. An 17, H. Anderhub 46, A.L. Anderson t4, V.P. Andreev 36, T. Angelescu 11, L. Antonov 4~ D. Antreasyan 7, G. Alkhazov 36, P. Arce 24, A. Arefiev 26, T. Azemoon 3, T. Aziz 8, P.V.K.S. Baba iT, P. Bagnaia(More)