Year: 2005
Type: article
Abstract: We present the results obtained by the BRAHMS experiment at the Relativistic Heavy Ion Collider (RHIC) for three colliding systems, namely: Au + Au , d + Au and p + p at [Formula: see text]. The main focus here is to give an overview of the main results on the reaction dynamics and on the properties of hot and high energy density matter produced in utra-relativistic heavy ion collisions. Measurement of particle production, particle spectra over a large rapidity interval as well as high pt measurements related to nuclear modification in Au + Au and d + Au collision are discussed. The observed number of charged particles produced per unit of rapidity at the central rapidity region indicates that a high energy density (> 5 GeV/fm3) system is created at the initial stage of the Au + Au reaction. From the particle spectra we deduced significant radial expansion (β ≈ 0.75) which is consistent with the large initial energy density. For Au + Au at η = 0 we observe the suppression of the high p T particles as compared to the elementary collisions, whereas for the d + Au reaction the Cronin type enhancement is observed. We also discuss to what extent these results can be taken as evidence for the quark gluon plasma (QGP). Finally, we present the nuclear modification effects in d + Au reaction as a function of rapidity and consider whether the observed suppression at forward rapidities constitutes sufficient evidence for a possible precursor state to the QGP, i.e. the Color Glass Condensate (CGC).
Authors: Paweł Staszel, I. Arsene, I. G. Bearden, D. Beavis, C. Besliu, B. Budick, H. Bøggild, C. Chasman, C. H. Christensen, P. Christiansen, J. Cibor, R. Debbe, E. Enger, J. J. Gaardhøje, M. Germinario, K. Hagel, H. Ito, A. Jipa, J. I. Jørdre, F. Jundt, C. E. Jørgensen, R. Karabowicz, E. J. Kim, T. Kozik, T. M. Larsen, J. H. Lee, Y. K. Lee, S. Lindal, R. Lystad, G. Løvhøiden, Z. Majka, A. Makeev, M. Mikelsen, M. Murray, J. Natowitz, B. Neuman, B. S. Nielsen, D. Ouerdane, R. Pł aneta, F. Rami, C. Ristea, O. Ristea, D. Röhrich, B. H. Samset, D. Sandberg, S. J. Sanders, R. A. Sheetz, P. Staszel, T. S. Tveter, F. Videbæk, R. Wada, Z. Yin, I. S. Zgura
Institutions: University of Copenhagen, Jagiellonian University, University of Bucharest, Brookhaven National Laboratory, New York University, Institute of Nuclear Physics, Polish Academy of Sciences, University of Oslo, Texas A&M University, University of Kansas, University of Bergen, Johns Hopkins University
Language: English
Subfield: Nuclear and High Energy Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W2763643311