Speaker
Description
High energy collider neutrinos have been observed for the first time by the FASER$\nu$ experiment. The detected spectrum of collider neutrinos scattering off nucleons can be used to probe neutrinophilic mediators with GeV-scale masses. We perform an analysis on the measured muon spectra at FASER$\nu$, and find that the bounds on the vector mediator from the current FASER$\nu$ data are comparable to the existing bounds at $m_{Z^\prime}\approx 0.2$ GeV. We also study the sensitivities to a neutrinophilic mediator at future Forward Physics Facilities including FLArE and FASER$\nu$2 by using both the missing transverse momentum and the charge identification information. We find that FLArE and FASER$\nu$2 can impose stronger bounds on both the scalar and vector neutrinophilic mediators than the existing bounds. The constraints on the scalar mediator can reach 0.08 (0.1) for $m_\phi\lesssim1$ GeV with (without) muon charge identification at FASER$\nu$2.