Searching for a single photon from lightest neutralino decays in R-parity-violating supersymmetry at FASER

A bstract In this work, we propose a search for a single photon at FASER and FASER2, produced from decays of bino-like, sub-GeV lightest neutralinos in the theoretical framework of the R-parity-violating (RPV) Minimal Supersymmetric Standard Model (MSSM). We consider a list of representative benchmark scenarios with one or two non-vanishing RPV couplings. The photon has an energy O(0 . 1) − O(1) TeV. We find a sensitivity reach for RPV couplings beyond the current bounds by orders of magnitude at FASER and FASER2.