Directed Flow of Identified Particles in Au+Au Collisions at √SNN=200 GeV at RHIC
STAR’s measurements of directed flow (v[subscript 1]) around midrapidity for π[superscript ±], K[superscript ±], K[subscript S][superscript 0], p, and p̅ in Au+Au collisions at √s[subscript NN]=200 GeV are presented. A negative v[subscript 1](y) slope is observed for most of produced particles (π[s...
| Main Authors: | , , , , , , , , , |
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| Other Authors: | |
| Format: | Article |
| Language: | en_US |
| Published: |
American Physical Society
2012
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| Online Access: | http://hdl.handle.net/1721.1/71605 https://orcid.org/0000-0002-5515-4563 https://orcid.org/0000-0001-5839-707X https://orcid.org/0000-0002-9107-6312 |
| Summary: | STAR’s measurements of directed flow (v[subscript 1]) around midrapidity for π[superscript ±], K[superscript ±], K[subscript S][superscript 0], p, and p̅ in Au+Au collisions at √s[subscript NN]=200 GeV are presented. A negative v[subscript 1](y) slope is observed for most of produced particles (π[superscript ±], K[superscript ±], K[subscript S][superscript 0], and p̅ ). In 5%–30% central collisions, a sizable difference is present between the v[subscript 1](y) slope of protons and antiprotons, with the former being consistent with zero within errors. The v[subscript 1] excitation function is presented. Comparisons to model calculations (RQMD, UrQMD, AMPT, QGSM with parton recombination, and a hydrodynamics model with a tilted source) are made. For those models which have calculations of v1 for both pions and protons, none of them can describe v[subscript 1](y) for pions and protons simultaneously. The hydrodynamics model with a tilted source as currently implemented cannot explain the centrality dependence of the difference between the v[subscript 1](y) slopes of protons and antiprotons. |
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