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Title: Recent Results from Phobos

Abstract

The PHOBOS detector is one of four heavy ion experiments at the Relativistic Heavy Ion Collider at Brookhaven National Laboratory. In this paper we will review some of the results of PHOBOS from the data collected in p+p, d+Au and Au+Au collisions at nucleon-nucleon center-of-mass energies up to 200 GeV. Evidence is found of the formation of a very high energy density and highly interactive system, which can not be described in terms of hadrons, and has a relatively low baryon density. There is evidence that the system formed is thermalized to a certain degree. Scaling with the number of participants and extended longitudinal scaling behavior are also observed in distributions of produced charged particles.

Authors:
; ; ; ; ; ; ; ;  [1];  [2]; ; ; ; ; ; ; ; ; ;  [3]
  1. University of Illinois at Chicago, Chicago, IL 60607-7059 (United States)
  2. Argonne National Laboratory, Argonne, IL 60439-4843 (United States)
  3. Brookhaven National Laboratory, Upton, NY 11973-5000 (United States) (and others)
Publication Date:
OSTI Identifier:
21054847
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 884; Journal Issue: 1; Conference: 6. Latin American symposium on nuclear physics and applications, Iguazu (Argentina), 3-7 Oct 2005; Other Information: DOI: 10.1063/1.2710611; (c) 2007 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
73 NUCLEAR PHYSICS AND RADIATION PHYSICS; BROOKHAVEN RHIC; CENTER-OF-MASS SYSTEM; DENSITY; DEUTERON REACTIONS; DISTRIBUTION; ENERGY DENSITY; GEV RANGE; GOLD 197 REACTIONS; GOLD 197 TARGET; MULTIPARTICLE SPECTROMETERS; MULTIPLE PRODUCTION; NUCLEONS; PARTICLE IDENTIFICATION; PROTON REACTIONS; PROTON-PROTON INTERACTIONS; REVIEWS; SCALING LAWS

Citation Formats

Garcia, Edmundo, Betts, R. R., Garcia, E., Halliwell, C., Hofman, D. J., Hollis, R. S., Iordanova, A., Sagerer, J., Smith, C. E., Back, B. B., Baker, M. D., Barton, D. S., Carroll, A., Chai, Z., George, N., Hauer, M., Holzman, B., Pak, R., Seals, H., and Sedykh, I. Recent Results from Phobos. United States: N. p., 2007. Web. doi:10.1063/1.2710611.
Garcia, Edmundo, Betts, R. R., Garcia, E., Halliwell, C., Hofman, D. J., Hollis, R. S., Iordanova, A., Sagerer, J., Smith, C. E., Back, B. B., Baker, M. D., Barton, D. S., Carroll, A., Chai, Z., George, N., Hauer, M., Holzman, B., Pak, R., Seals, H., & Sedykh, I. Recent Results from Phobos. United States. doi:10.1063/1.2710611.
Garcia, Edmundo, Betts, R. R., Garcia, E., Halliwell, C., Hofman, D. J., Hollis, R. S., Iordanova, A., Sagerer, J., Smith, C. E., Back, B. B., Baker, M. D., Barton, D. S., Carroll, A., Chai, Z., George, N., Hauer, M., Holzman, B., Pak, R., Seals, H., and Sedykh, I. Mon . "Recent Results from Phobos". United States. doi:10.1063/1.2710611.
@article{osti_21054847,
title = {Recent Results from Phobos},
author = {Garcia, Edmundo and Betts, R. R. and Garcia, E. and Halliwell, C. and Hofman, D. J. and Hollis, R. S. and Iordanova, A. and Sagerer, J. and Smith, C. E. and Back, B. B. and Baker, M. D. and Barton, D. S. and Carroll, A. and Chai, Z. and George, N. and Hauer, M. and Holzman, B. and Pak, R. and Seals, H. and Sedykh, I.},
abstractNote = {The PHOBOS detector is one of four heavy ion experiments at the Relativistic Heavy Ion Collider at Brookhaven National Laboratory. In this paper we will review some of the results of PHOBOS from the data collected in p+p, d+Au and Au+Au collisions at nucleon-nucleon center-of-mass energies up to 200 GeV. Evidence is found of the formation of a very high energy density and highly interactive system, which can not be described in terms of hadrons, and has a relatively low baryon density. There is evidence that the system formed is thermalized to a certain degree. Scaling with the number of participants and extended longitudinal scaling behavior are also observed in distributions of produced charged particles.},
doi = {10.1063/1.2710611},
journal = {AIP Conference Proceedings},
number = 1,
volume = 884,
place = {United States},
year = {Mon Feb 12 00:00:00 EST 2007},
month = {Mon Feb 12 00:00:00 EST 2007}
}
  • A selection of experimental results from the PHOBOS Collaboration relevant for probing high-energy nuclear collisions with high transverse momentum particles is presented. The inclusive yields of charged particles and comparisons between nuclear and elementary collisions already reveal a large amount of parton energy loss in the hot and dense medium created in heavy ion collisions. Remarkable scaling and factorization features are observed, unifying the data taken at various collision energies, centralities and nuclear sizes. To further analyze the nature of the energy loss, a measurement of pseudorapidity ({Delta}{eta}) and azimuthal angle ({Delta}{phi}) correlations between high transverse momentum charged hadrons (p{submore » T} > 2.5 GeV/c) and all associated charged particles is presented at both short-range (small {Delta}{eta}) and long-range (large {Delta}{eta}) over a continuous detector acceptance covering -4 < {Delta}{eta} < 2. Various near- and away-side features of the correlation structure are discussed as a function of centrality in Au+Au collisions at {radical}s{sub NN} = 200 GeV. The results provide new information about the longitudinal ({Delta}{eta}) extent of the near-side 'ridge' structure, first observed by the STAR Collaboration over a narrower {eta} range. In central Au+Au collisions the ridge structure extends to at least {Delta}{eta} = 4, and its strength completely diminishes as collisions become more peripheral.« less
  • No abstract prepared.
  • No abstract prepared.
  • We present new results from the PHOBOS experiment at RHIC on event-by-event fluctuations of particle multiplicities and angular distributions in nucleus-nucleus collisions at RHIC. Our data for Au+Au collisions at {radical}(s{sub NN}) = 200 GeV show that at a level of 10-4 or less, no rare, large-amplitude fluctuations in the total multiplicity distributions or the shape of the pseudorapidity distributions are observed. We however find significant short-range multiplicity correlations in these data, that can be described as particle production in clusters. In Cu+Cu collisions, we observe large final-state azimuthal anisotropies {nu}2. A common scaling behavior for Cu+Cu and Au+Au formore » these anisotropies emerges when fluctuations in the initial state geometry are taken into account.« less