학술논문
Results from the BRAHMS experiment at RHIC
Document Type
Article
Author
Collaboration:, D Röhrich for the BRAHMS; Bearden, I G; Beavis, D; Besliu, C; Blyakhman, Y; Brzychczyk, J; Budick, B; Bøggild, H; Chasman, C; Christensen, C H; Christiansen, P; Cibor, J; Debbe, R; Gaardhøje, J J; Germinario, M; Grotowski, K; Hagel, K; Hansen, O; Holm, A; Holme, A K; Ito, H; Jakobsen, E; Jipa, A; Jordre, J I; Jundt, F; Jørgensen, C E; Keutgen, T; Kim, E J; Kozik, T; Larsen, T M; Lee, J H; Lee, Y K; Løvhøiden, G; Majka, Z; Makeev, A; McBreen, B; Murray, M; Natowitz, J; Niels, B S
Source
Journal of Physics G: Nuclear and Particle Physics; July 1, 2002, Vol. 28 Issue: 7 p1841-1851, 11p
Subject
Language
ISSN
09543899; 13616471
Abstract
Results from the BRAHMS Collaboration for the inaugural physics run with the relativistic heavy ion collider (RHIC), Au + Au collisions at &surd;sNN &equal; 130 GeV in the late summer of 2000, and some results of the very first data from the summer of 2001 at &surd;sNN &equal; 200 GeV are presented. Here the main focus is on the determination of the pseudorapidity distribution of charged particles as a function of collision centrality and on the measurement of the antiproton to proton and the K− to K+ ratios as a function of rapidity. The pseudorapidity density at midrapidity reaches dN(ch)/dη &equal; 553 ± 36 for the most central collisions (05&percent;) at &surd;sNN &equal; 130 GeV; the corresponding number for a higher energy is dN(ch)/dη &equal; 632 ± 36, demonstrating an increase in multiplicity of about 14&percent;. The measured antiproton/proton ratios peak at midrapidity around N(&barp;)/N(p) &equal; 0.64 ± 0.06 and drop to 0.41 ± 0.04 at y ≈ 2 for &surd;sNN &equal; 130 GeV reactions; the K− to K+ ratios are 0.90 ± 0.06 (y ≈ 0) and 0.83 ± 0.1 (y ≈ 2.5).