Non-standard Neutrino and $Z^{\prime }$ Interactions at the FASER$\nu$ and the LHC

Abstract

We study the impact of non-standard neutrino interactions in the context of a new gauge boson $Z^{\prime }$ in neutral-current deep-inelastic scattering performed in ForwArd Search ExpeRiment-$\nu$ (FASER$\nu$) and in monojet production at the Large Hadron Collider (LHC). We simulate the neutral-current deep-inelastic neutrino-nucleon scattering $\nu N\to \nu N$ at FASER$\nu$ in the presence of an additional $Z^{\prime }$ boson, and estimate the anticipated sensitivities to the gauge coupling in a wide range of $Z^{\prime }$ mass. At the LHC, we study the effect of $Z^{\prime }$ on monojet production, which can be enhanced in regions with large missing transverse momenta. We then use the recent results from ATLAS with an integrated luminosity of 139 fb${}^{-1}$ to improve the limits on the gauge coupling of $Z^{\prime }$. We interpret such limits on $Z^{\prime }$ gauge couplings as bounds on effective non-standard neutrino interactions. We show that the FASER$\nu$ and the LHC results cover the medium and high energy scales, respectively, and complement one another.

Comments: 22 pages, 7 figures