Abstract
The chiral magnetic wave (CMW) has been theorized to propagate in the
Quark-Gluon Plasma formed in high-energy heavy-ion collisions. It could cause a
finite electric quadrupole moment of the collision system, and may be observed
as a dependence of elliptic flow, $v_{2}$, on the asymmetry between positively
and negatively charged hadrons, $A_{\rm ch}$. However, non-CMW mechanisms, such
as local charge conservation (LCC) and hydrodynamics with isospin effect, could
also contribute to the experimental observations. Here we present the STAR
measurements of elliptic flow $v_{2}$ and triangular flow $v_{3}$ of charged
pions, along with $v_{2}$ of charged kaons and protons, as functions of $A_{\rm
ch}$ in Au+Au collisions at $\sqrt{s_{\rm NN}}$ = 200 GeV. The slope parameters
of $\Delta v_{2}$($A_{\rm ch}$) and $\Delta v_{3}$($A_{\rm ch}$) are reported
and compared to investigate the LCC background. The similarity between pion and
kaon slopes suggests that the hydrodynamics is not the dominant mechanism. The
difference between the normalized $\Delta v_{2}$ and $\Delta v_{3}$ slopes,
together with the small slopes in p+Au and d+Au collisions at $\sqrt{s_{\rm
NN}}$ = 200 GeV, suggest that the CMW picture remains a viable interpretation
at RHIC.