Description
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 |
