Measurement of single electron event anisotropy in Au+Au collisions at √s_NN=200 GeV

Abstract

The transverse momentum dependence of the azimuthal anisotropy parameter v₂, the second harmonic of the azimuthal distribution, for electrons at midrapidity (|η|<0.35) has been measured with the PHENIX detector in Au+Au collisions at √s_NN=200 GeV. The measurement was made with respect to the reaction plane defined at high rapidities (|η|=3.1-3.9). From the result we have measured the v₂ of electrons from heavy flavor decay after subtraction of the v₂ of electrons from other sources such as photon conversions and Dalitz decay from light neutral mesons. We observe a nonzero single electron v₂ with a 90% confidence level in the intermediate-p_T region. The precision of the present data set does not permit us to conclude definitively that heavy quarks exhibit thermalization with the transverse flow of the bulk matter.