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$\nu$, FASER$\nu 2$, FLArE (10 tons), and FLArE (100 tons) using the neutrino-nucleon scattering ($\nu N\to \nu N^{\mathrm{\prime }}$ and $\nu N\to l{N}^{\mathrm{\prime }}$). We cover a wide mass range of ${10}^{-3}$ GeV $\le M_{LQ}\le {10}^4$ 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.