Charge-Asymmetry Dependence of Proton Elliptic Flow in 200 GeV Au$+$Au Collisions

The chiral magnetic wave (CMW) is predicted to manifest a finite electric quadrupole moment in the quark-gluon plasma produced in high-energy heavy-ion collisions [1]. This quadrupole moment generates a divergence in the azimuthal anisotropy ($v$2) of positively and negatively charged particles such that $v$2($+)$ \textless $v$2(-). This effect is proportional to the apparent charge asymmetry (Ach) of particles in the same rapidity window. The Ach dependence of $v$2$^{\mathrm{\thinspace }}$has already been observed in the cases of charged pions and kaons [2, 3]. We present preliminary STAR measurements of $v$2$^{\mathrm{\thinspace }}$for protons and anti-protons as a function of Ach$^{\mathrm{\thinspace }}$from $\surd $sNN$^{\thinspace }=$ 200 GeV Au$+$Au collisions for different centrality classes. The results are then compared with the previously reported results of pions and kaons. [1] Y. Burnier, D. Kharzeev, J. Liao and H. Yee, Phys. Rev. Lett. \textbf{107} (2011) 052303. [2] L. Adamczyk, \textit{et al}, Phys. Rev. Lett.?\textbf{114}?(2015) 252302. [3] Q.-Y Shou, Nucl. Phys. A \textbf{931} (2014) 758.