# Quark Matter 2019 - the XXVIIIth International Conference on Ultra-relativistic Nucleus-Nucleus Collisions

3-9 November 2019
Wanda Reign Wuhan Hotel
Asia/Shanghai timezone

## Investigate the possible physics mechanisms of the CMW-like flow signals

5 Nov 2019, 15:40
20m
Ball Room 2 (Wanda Reign Wuhan Hotel)

### Ball Room 2

#### Wanda Reign Wuhan Hotel

Oral Presentation Chirality, vorticity and spin polarization

### Speaker

Haojie Xu (Huzhou University)

### Description

The interplay between the chiral magnetic effect and the chiral separation effect can lead to a collective excitation, a phenomenon called Chiral Magnetic Wave (CMW). Previous measurement of a positive slope for the charge asymmetry ($A_{\rm ch}$) dependence of the $\pi^{+}$ and $\pi^{-}$ flow difference $\Delta v_{2}(A_{\rm ch})\equiv v_{2}^{\pi^{-}}(A_{\rm ch}) - v_{2}^{\pi^{+}}(A_{\rm ch})$, indicated effects that are consistent with the CMW, but firm conclusions have not been established because of possible background contaminations in those measurements. In this work, we study the effects of resonance decays (local charge conservation) and find strong sensitivities of the $\Delta v_{2} (A_{\rm ch})$ slope parameter on kinematics. We then study several main sources of pions in relativistic heavy ion collisions, and find that the competitions among the different $\pi$ sources can yield another linear $A_{\rm ch}$ term due to their multiplicity fluctuations and different $v_{2}$ values. This linear $A_{\rm ch}$ term does not require any $A_{\rm ch}$ dependence in the pion $v_{2}$ from each individual source. We discuss the implications of our findings on the experimental search for the CMW.

### Primary authors

Haojie Xu (Huzhou University) Dr Jie Zhao (Purdue University) Fuqiang Wang (Purdue University (US))

### Presentation Materials

 XuHaojie_CMW.pdf XuHaojie_CMW.PPTX