Results from the PHOBOS Experiment at RHIC (original) (raw)
Related papers
Physical Review C, 2002
The centrality dependence of the charged-particle multiplicity density at mid-rapidity in Pb-Pb collisions at √ s NN = 2.76 TeV is presented. The charged-particle density normalized per participating nucleon pair increases by about a factor of two from peripheral (70-80%) to central (0-5%) collisions. The centrality dependence is found to be similar to that observed at lower collision energies. The data are compared with models based on different mechanisms for particle production in nuclear collisions.
Scaling of charged particle production in d+Au collisions at sNN=200GeV
Physical Review C, 2005
The measured pseudorapidity distributions of primary charged particles over a wide pseudorapidity range of |η| ≤ 5.4 and integrated charged particle multiplicities in d + Au collisions at √ s N N = 200 GeV are presented as a function of collision centrality. The longitudinal features of d+Au collisions at √ s N N = 200 GeV are found to be very similar to those seen in p + A collisions at lower energies. The total multiplicity of charged particles is found to scale with the total number of participants according to N dAu ch = 1 2 Npart N pp ch and the energy dependence of the density of charged particles produced in the fragmentation region exhibits extensive longitudinal scaling.
Charged-Particle Multiplicity near Midrapidity in Central Au+Au Collisions at sNN=56 and 130 GeV
Physical Review Letters, 2000
We present the first measurement of pseudorapidity densities of primary charged particles near mid-rapidity in Au+Au collisions at √ s = 56 and 130 AGeV. For the most central collisions, we find the charged particle pseudorapidity density to be dN/dη| |η|<1 = 408±12(stat) ±30(syst) at 56 AGeV and 555 ± 12(stat) ± 35(syst) at 130 AGeV, values that are higher than any previously observed in nuclear collisions. Compared to proton-antiproton collisions, our data show an increase in the pseudorapidity density per participant by more than 40% at the higher energy.
Physical Review Letters, 2011
The centrality dependence of the charged-particle multiplicity density at mid-rapidity in Pb-Pb collisions at √ s NN = 2.76 TeV is presented. The charged-particle density normalized per participating nucleon pair increases by about a factor of two from peripheral (70-80%) to central (0-5%) collisions. The centrality dependence is found to be similar to that observed at lower collision energies. The data are compared with models based on different mechanisms for particle production in nuclear collisions.
2010
Pseudorapidity distributions of charged particles emitted in Au+AuAu+AuAu+Au, Cu+CuCu+CuCu+Cu, d+Aud+Aud+Au, and p+pp+pp+p collisions over a wide energy range have been measured using the PHOBOS detector at RHIC. The centrality dependence of both the charged particle distributions and the multiplicity at midrapidity were measured. Pseudorapidity distributions of charged particles emitted with ∣eta∣<5.4|\eta|<5.4∣eta∣<5.4, which account for between 95% and 99% of the total charged-particle emission associated with collision participants, are presented for different collision centralities. Both the midrapidity density, dNch/detadN_{ch}/d\etadNch/deta, and the total charged-particle multiplicity, NchN_{ch}Nch, are found to factorize into a product of independent functions of collision energy, sqrtsNN\sqrt{s_{_{NN}}}sqrtsNN, and centrality given in terms of the number of nucleons participating in the collision, NpartN_{part}Npart. The total charged particle multiplicity, observed in these experiments and those at lower energies, assumes a linear dependence of (lnsNN)2(\ln s_{_{NN}})^2(lnsNN)2 over the full range of collision energy of sqrtsNN\sqrt{s_{_{NN}}}sqrtsNN=2.7-200 GeV.
CHARGED PARTICLE MULTIPLICITY DISTRIBUTIONS FROM p+p TO Au+Au COLLISIONS AT RHIC
2006
The distributions of charged particles from heavy ion collisions have been measured by the PHOBOS collaboration. Results from Au+Au collisions at various energies and over a broad range of centrality are presented and discussed. This data are compared to p+p, d+Au and Cu+Cu collisions at the corresponding energy and centrality.
Physical Review Letters, 2010
The centrality dependence of the charged-particle multiplicity density at mid-rapidity in Pb-Pb collisions at √ s NN = 2.76 TeV is presented. The charged-particle density normalized per participating nucleon pair increases by about a factor of two from peripheral (70-80%) to central (0-5%) collisions. The centrality dependence is found to be similar to that observed at lower collision energies. The data are compared with models based on different mechanisms for particle production in nuclear collisions.