First Mass-resolved Measurement of High-Energy Cosmic-Ray Antiprotons.
We report new results for the cosmic-ray antiproton-to-proton ratio from 3 to 50 GeV at the top of the atmosphere. These results represent the first measurements, on an event-by-event basis, of mass-resolved antiprotons above 18 GeV. The results were obtained with the NMSU-WIZARD/CAPRICE98 balloon-borne magnet spectrometer equipped with a gas-RICH (Ring-Imaging Cerenkov) counter and a silicon-tungsten imaging calorimeter. The RICH detector was the first ever flown that is capable of identifying charge-one particles at energies above 5 GeV. The spectrometer was flown on 1998 May 28-29 from Fort Sumner, New Mexico. The measured p&d1;/p ratio is in agreement with a pure secondary interstellar production.
Bergström
D
Boezio
M
Carlson
P
Francke
T
Grinstein
S
Khalchukov
F
Suffert
M
Hof
M
Kremer
J
Menn
W
Simon
M
Stephens
SA
Ambriola
ML
Bellotti
R
Cafagna
F
Ciacio
F
Circella
M
De Marzo C
Finetti
N
Papini
P
Piccardi
S
Spillantini
P
Bartalucci
S
Ricci
M
Casolino
M
De Pascale MP
Morselli
A
Picozza
P
Sparvoli
R
Bonvicini
V
Schiavon
P
Vacchi
A
Zampa
N
Mitchell
JW
Ormes
JF
Streitmatter
RE
Bravar
U
Stochaj
SJ