Balance functions from Au+Au, d+Au, and p+p collisions at {radical}(s{sub NN})=200 GeV

Journal Article · Sun Aug 15 04:00:00 EDT 2010 · Physical Review. C, Nuclear Physics

DOI:https://doi.org/10.1103/PHYSREVC.82.024905· OSTI ID:21419449

Aggarwal, M M; Bhati, A K; Pruthi, N K ^[1]; Ahammed, Z; Dong, X; Grebenyuk, O; Hjort, E; Jacobs, P; Kikola, D P; Kiryluk, J; Klein, S R; Masui, H; Matis, H S; Odyniec, G; Olson, D; Ploskon, M A; Poskanzer, A M; Powell, C B; Ritter, H G; Rose, A ^[2]

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1. Panjab University, Chandigarh 160014 (India)
2. Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)

Balance functions have been measured for charged-particle pairs, identified charged-pion pairs, and identified charged-kaon pairs in Au+Au, d+Au, and p+p collisions at {radical}(s{sub NN})=200 GeV at the Relativistic Heavy Ion Collider using the STAR detector. These balance functions are presented in terms of relative pseudorapidity, {Delta}{eta}, relative rapidity, {Delta}y, relative azimuthal angle, {Delta}{phi}, and invariant relative momentum, q{sub inv}. For charged-particle pairs, the width of the balance function in terms of {Delta}{eta} scales smoothly with the number of participating nucleons, while hijing and urqmd model calculations show no dependence on centrality or system size. For charged-particle and charged-pion pairs, the balance functions widths in terms of {Delta}{eta} and {Delta}y are narrower in central Au+Au collisions than in peripheral collisions. The width for central collisions is consistent with thermal blast-wave models where the balancing charges are highly correlated in coordinate space at breakup. This strong correlation might be explained by either delayed hadronization or limited diffusion during the reaction. Furthermore, the narrowing trend is consistent with the lower kinetic temperatures inherent to more central collisions. In contrast, the width of the balance function for charged-kaon pairs in terms of {Delta}y shows little centrality dependence, which may signal a different production mechanism for kaons. The widths of the balance functions for charged pions and kaons in terms of q{sub inv} narrow in central collisions compared to peripheral collisions, which may be driven by the change in the kinetic temperature.

• OSTI ID: 21419449
• Journal Information: Physical Review. C, Nuclear Physics, Journal Name: Physical Review. C, Nuclear Physics Journal Issue: 2 Vol. 82; ISSN 0556-2813; ISSN PRVCAN
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ACCELERATORS
ATOM COLLISIONS
ATOM-ATOM COLLISIONS
BARYON-BARYON INTERACTIONS
BARYONS
BASIC INTERACTIONS
BOSONS
BROOKHAVEN RHIC
CHARGED PARTICLES
COLLISIONS
CORRELATIONS
DEUTERONS
ELEMENTARY PARTICLES
ELEMENTS
ENERGY RANGE
EXPLOSIONS
FERMIONS
GEV RANGE
GOLD
HADRON-HADRON INTERACTIONS
HADRONS
HEAVY ION ACCELERATORS
INTERACTIONS
KAON-KAON INTERACTIONS
KAONS
MESON-MESON INTERACTIONS
MESONS
METALS
NUCLEON-NUCLEON INTERACTIONS
NUCLEONS
PAIRING INTERACTIONS
PARTICLE INTERACTIONS
PARTICLE PROPERTIES
PARTICLE RAPIDITY
PERIPHERAL COLLISIONS
PION-PION INTERACTIONS
PIONS
PROTON-NUCLEON INTERACTIONS
PROTON-PROTON INTERACTIONS
PSEUDOSCALAR MESONS
STORAGE RINGS
STRANGE MESONS
STRANGE PARTICLES
STRONG INTERACTIONS
TRANSITION ELEMENTS