Περίληψη:
Fast secondary particles from interactions of K+ at 70 GeV/c and K- at 110 GeV/c in the BEBC hydrogen bubble chamber are identified by use of the relativistic rise of ionization in argon. The ionization is measured in a large multicell ionization counter system, the External Particle Identifier (EPI). The operation of this hybrid system, the calibration and the procedures of off-line analysis leading to particle identification are described. For a sample of 9283 secondary particles collected in the K+ p experiment, we present the measurements of ionization, and the determination of acceptance and identification efficiencies. The momentum-dependent populations of pions, kaons and protons have been obtained. Track by track identification procedures yielding samples of pions and kaons with a contamination {less-than or approximate} 12% are discussed. A study of the resolution of the EPI in these experimental conditions shows average values in a range of 7.6% to 11% depending on the number of ionization samples remaining after removal of background. These values extrapolate to a value consistent with the 6.6% fwhm measured over the whole device for single particles during calibration with a 50 GeV/c π- beam. © 1983.
Συγγραφείς:
Baruzzi, V.
Carosio, R.
Crijns, F.
Gerdyukov, L.
Goldschmidt-Clermont, Y.
Grant, A.
Johnson, D.
Kröner, F.
Lehraus, I.
Matthewson, R.
Milstene, C.
Nikolaenko, V.
Oren, Y.
Petrovikh, Y.
Ross, R.T.
Sixel, P.
Spyropoulou-Stassinaki, M.
Stergiou, A.
Tejessy, W.
Theocharopoulos, P.
Vassiliadis, G.
Wright, P.R.S.
Zoll, J.
