Balance Functions from Au+Au Collisions at √{sNN} = 7.7 to 200 GeV
Abstract
We present balance functions from Au+Au collisions at √{sNN} = 7.7 to 200 GeV measured at STAR and compare with recent results for Pb+Pb collisions at √{sNN} = 2.76 TeV. We find that the balance function narrows as the collisions become more central and as the incident energy increases, which is consistent with the concept of delayed hadronization of a deconfined quark-gluon plasma (QGP). We also present balance functions for π+π- pairs, K+K- pairs, p p pairs, and pK- pairs from central Au+Au collisions at √{sNN} = 200 GeV. We compare to a model that relates these balance functions to the correlations of up, down, and strange quarks in the QGP created in central Au+Au collisions at √{sNN} = 200 GeV. Our results are consistent with two waves of charge creation in time, one early in the collision ( 1 fm/ c) and a second at hadronization ( 5 - 10 fm/ c). We find that the densities of up, down, and strange quarks in the QGP extracted from the model comparison are consistent with current lattice gauge calculations.
- Publication:
-
APS Division of Nuclear Physics Meeting Abstracts
- Pub Date:
- September 2014
- Bibcode:
- 2014APS..DNP.FJ005W