Measurement of azimuthal anisotropy of hadrons in Au+Au collisions from the beam energy scan program by the PHENIX experiment at RHIC

Abstract

The elliptic flow as given by the second term of the Fourier series for the azimuthal distribution of particles with respect to the event plane is believed to carry information on the initial geometrical anisotropy. The large azimuthal anisotropy of the particle emission was observed in heavy ion collisions at RHIC in 2001. In Au+Au = 200 GeV collisions, the elliptic flow of identified charged hadrons was found to scale with the number of constituent quarks, which may be an indication of the flow of constituent quarks in the QGP phase. An event plane detector, RxPN, was installed in the PHENIX experiment in 2007, in order to improve the resolution of the event plane determination. The RxPN detector was also used to make accurate measurements of the elliptic flow at lower collision energies, where the transition of the QGP might be explored. The latest elliptic flow measurement for identified hadrons in Au+Au collisions from the beam energy scan program at the PHENIX will be presented and discussed.