  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
$\Delta\gamma$ is contaminated by a major background from resonance decays
coupled with elliptic flow. In this contribution, we propose differential
$\Delta\gamma$ measurements as function of the pair invariant mass ($m_{\rm
inv}$). The $\Delta\gamma$ in the high $m_{\rm inv}$ region is essentially free
of resonance backgrounds. In the low $m_{\rm inv}$ region, the $\Delta\gamma$
backgrounds show resonance peaks. The CME signal, presumably smooth in $m_{\rm
inv}$, may thus be extracted from a two-component model fit. We demonstrate the
feasibility and effectiveness of this novel method by using the AMPT and
toy-model Monte-Carlo simulations. We also discuss an application of the method
in data analysis.
