Effects of nuclear charge fluctuations on dilepton photoproduction

Guansong Li,Kai Zhou,Baoyi Chen

Figure 3. Relative standard deviation $\tfrac{\sqrt{\langle {\left(X-\langle X\rangle \right)}^{2}\rangle }}{\langle X\rangle }$ for dilepton photoproduction with event-by-event fluctuating EM fields as a function of invariant mass at RHIC $\sqrt{{s}_{{NN}}}=200\,\mathrm{GeV}$ Au-Au collisions with impact parameter b = 10, 12, 15 fm (solid, dashed, dotted-dashed lines). The rapidity cut of the dileptons is taken as $| {y}_{{e}^{+}{e}^{-}}| \lt 1$. And $X\equiv {\rm{d}}{N}/{{\rm{d}}{M}}_{{e}^{+}{e}^{-}}$ is the dilepton spectrum.