Impact of the nuclear structure on the isobar run at RHIC

No chiral-magnetic effect signature has been observed in the experimental analysis of the isobar run at RHIC [1]. In this talk, based on [2], we highlight the influence of the nuclear structure of the isobar systems on the CME search within a relativistic hadronic transport approach (SMASH). We show that the quadrupole deformation of Ru enhances the eccentricity ratio between the isobars in ultra-central collisions up to 10%, thus leading to not identical CME backgrounds in the two isobar systems. In addition, the neutron skin of Zr [3] reduces a factor of 2, from 10% to 5% , the magnetic field strength difference between in peripheral collisions. These two predictions suggest a significantly smaller CME signal to background ratio than previous expected, as has been confirmed experimentally.