# Beam-Energy Dependence of Directed Flow of Protons, Antiprotons and Pions in Au+Au Collisions

Abstract : Rapidity-odd directed flow($v_1$) measurements for charged pions, protons and antiprotons near mid-rapidity ($y=0$) are reported in $\sqrt{s_{NN}} =$ 7.7, 11.5, 19.6, 27, 39, 62.4 and 200 GeV Au + Au collisions as recorded by the STAR detector at the Relativistic Heavy Ion Collider (RHIC). At intermediate impact parameters, the proton and net-proton slope parameter $dv_1/dy|_{y=0}$ shows a minimum between 11.5 and 19.6 GeV. In addition, the net-proton $dv_1/dy|_{y=0}$ changes sign twice between 7.7 and 39 GeV. The proton and net-proton results qualitatively resemble predictions of a hydrodynamic model with a first-order phase transition from hadronic matter to deconfined matter, and differ from hadronic transport calculations.
Document type :
Journal articles
Domain :

http://hal.in2p3.fr/in2p3-00931159
Contributor : Sylvie Flores <>
Submitted on : Wednesday, January 15, 2014 - 8:01:17 AM
Last modification on : Thursday, February 7, 2019 - 3:18:19 PM

### Citation

L. Adamczyk, W. Borowski, S. Kabana. Beam-Energy Dependence of Directed Flow of Protons, Antiprotons and Pions in Au+Au Collisions. Physical Review Letters, American Physical Society, 2014, 112, pp.162301. ⟨10.1103/PhysRevLett.112.162301⟩. ⟨in2p3-00931159⟩

Record views