Probing light neutralinos from pair-produced sleptons with displaced vertices at the high-luminosity LHC

Abstract

We study light neutralinos ($\tilde{\ddot{I}}{‡}_1^0$) with masses ranging from 10 GeV to several hundred GeV within the framework of R-parity-violating (RPV) supersymmetry. These light neutralinos can be long-lived, decaying with a macroscopic displacement (order cm) inside the LHC main detectors. Complementing previous works on the subject, here we focus on their production through the electroweak pair production of left-chiral sleptons (${\tilde{e}}_L$), with the signal process $pp\to {\tilde{e}}_L^{+}{\tilde{e}}_L^{-}\to e^{+}\tilde{\ddot{I}}{‡}_1^0{e}^{-}\tilde{\ddot{I}}{‡}_1^0$. In contrast to the previous study with a singly produced slepton, where the RPV coupling $\hat{I}{»}_{111}^{\prime }$ induces both the production and decay of the light neutralino, in our scenario the production proceeds through Drell-Yan-like processes that are essentially independent of RPV couplings. Correspondingly, we implement a displaced-vertex search strategy for which our numerical analysis shows that the high-luminosity LHC can probe $\hat{I}{»}_{111}^{\prime }$ values up to three orders of magnitude smaller, and neutralino masses up to about four times larger than those accesible in the previously studied single-slepton production scenario.

19 pages, 7 figures, 2 tables. Modified text, figures and tables. Conclusions unchanged. Version accepted for publication in JHEP