May 13 – 19, 2018
Venice, Italy
Europe/Zurich timezone
The organisers warmly thank all participants for such a lively QM2018! See you in China in 2019!

A novel invariant mass method to isolate resonance backgrounds from the chiral magnetic effect

May 16, 2018, 6:30 PM
Sala Casinò, 1st Floor (Palazzo del Casinò)

Sala Casinò, 1st Floor

Palazzo del Casinò

Parallel Talk Chirality, vorticity and polarisation effects Chirality, vorticity and polarisation effects


The Chiral Magnetic Effect (CME) refers to charge separation along a strong magnetic field, due to topological charge fluctuations in QCD. Charge correlation ($\Delta\gamma$) signals consistent with CME have been first observed almost a decade ago. It has also been known since then that the $\Delta\gamma$ was contaminated by a major background from resonance decays coupled with the elliptic flow ($v_{2}$). The invariant mass ($m_{inv}$) dependence of the $\Delta\gamma$ has, rather surprisingly, not been examined until recently [1].

In this talk, we propose differential $\Delta\gamma$ measurements as function of $m_{inv}$. By restricting to high $m_{inv}$, e.g. above 2 GeV/$c^{2}$, one may extract resonance-free CME signal where particle transverse momenta are still relatively low ($\sim$1.2 GeV/$c$). In the low $m_{inv}$ region, the backgrounds show resonance peaks and the CME signal is presumably smooth in $m_{inv}$. These different behaviors can be exploited by a two-component model to extract the CME signal at low $m_{inv}$. We demonstrate the feasibility and effectiveness of this novel method by using the AMPT and toy-model Monte-Carlo simulations. The power of our method on the upcoming isobaric collisions at RHIC will also be discussed.

[1] J. Zhao, H. Li, F. Wang. Isolating backgrounds from the chiral magnetic effect, arXiv:1705.05410

Content type Theory
Centralised submission by Collaboration Presenter name already specified

Primary authors

Prof. Hanlin Li (Wuhan University of Science and Technology & Purdue University) Dr Jie Zhao (Purdue University)

Presentation materials