Chiral magnetic effect enhancement at lower collision energies

We extend previous holographic studies of the chiral magnetic effect (CME) by incorporating a time-dependent magnetic field. Various magnetic field profiles proposed in the literature are implemented, and their impact on the CME signal is analyzed in both static and expanding backgrounds. Interestingly, the integrated chiral magnetic current can exhibit a nonmonotonic dependence on the collision energy. Our results suggest that the CME signal is enhanced at collision energies below <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:msqrt><a:mi>s</a:mi></a:msqrt><a:mo>=</a:mo><a:mn>200</a:mn><a:mtext> </a:mtext><a:mtext> </a:mtext><a:mi>GeV</a:mi></a:math>. In addition, we derive a quasiequilibrium formula for the chiral magnetic effect in the expanding background that is valid at late times.