Leptoquark search at the Forward Physics Facility

In this study, we calculate the sensitivity reach on the vector leptoquark (LQ) $U_1$ at the experiments proposed in Forward Physics Facility (FPF), including FASER$ν$, FASER$\nu2$, FLArE (10 tons), and FLArE (100 tons) using the neutrino-nucleon scattering ($νN \rightarrow νN'$ and $νN \rightarrow l N'$). We cover a wide mass range of $10^{-3}$ GeV $\leq M_{LQ}\leq 10^4$ GeV. The new result shows that the FLArE (100 tons) offers the best sensitivity to the LQ model. The sensitivity curves for all the experiments follow a similar pattern with weakened sensitivities with the increment of the LQ mass. We combine the sensitivities obtained from the neutral- and charged-current interactions of the neutrinos.