Vector-current correlation and charge separation via chiral-magnetic effect

الأصل · EN

We investigate the vector-current correlation Pimu nu (VCC) in the presence of a strong external magnetic field (B₀ in the z direction) at low temperature (T<Tᶜhic) with C- and CP-violations, indicated by the nonzero chiral-chemical potential (muchi>0), i.e. the chiral-magnetic effect (CME). For this purpose, we employ the instanton-vacuum configuration at finite T with nonzero topological charge (Qₜ>0). From the numerical calculations, it turns out that the longitudinal component of the connected VCC is liner in B₀ and shows a bump, representing a corresponding vector meson at |Q|=(300 400) MeV for T=0. The bump becomes enhanced as T increases and the bump position shifts to a lager |Q| value. In the limit of |Q|->0, the transverse component of the connected VCC disappears, whereas the longitudinal one remains finite and gets insensitive to B₀ with respect to T, due to diluting instanton contributions. Considering a simple collision geometry of HIC and some assumptions on the induced magnetic field and screening effect, we can estimate the charge separation (ChS) as a function of centrality using the present results for VCC. The numerical results show a qualitative agreement with experiments for the Au+Au and Cu+Cu collisions. These results are almost independent on the source of CME, instanton or sphaleron, as long as the CME current is linear in B₀.