The Single Photon Signature of a Light Long-lived Neutralino at Remote Detectors at the LHC

Abstract

We investigate the phenomenology of light long-lived neutralinos in R-parity violating supersymmetric models, focusing on the proposed remote detectors $\text{ANUBIS}$, $\text{CODEX-b}$, $\text{FACET}$, $\text{FASER}$, $\text{FASER2}$, $\text{MAPP}$, $\text{MAPP2}$, and $\text{MATHUSLA}$ at the LHC. We assume the production of the neutralinos at the ATLAS or CMS interaction points via rare scalar meson decays induced by R-parity violating couplings. We study six supersymmetric R-parity violating benchmark scenarios in which the dominant neutralino decay is ${\tilde{\chi }}_1^0\to \gamma +\nu$. For each scenario, we determine the projected search sensitivity at the above listed detectors. Extending previous work focused primarily on $\text{FASER}$ and $\text{FASER2}$, we improve the simulation by taking into account the extended flight path of the parent meson. We find that $\text{ANUBIS}$ provides the best sensitivity to our benchmark scenarios and $\text{FASER}$ the least among the considered experiments, while of course $\text{FASER}$ has already taken data.

Comments: 28 pages, 8 figures, 4 tables