Probing the νR-philic Z′ at DUNE near detectors

Abstract

We consider a hidden U(1) gauge symmetry under which only the right-handed neutrinos (νR) are charged. The corresponding gauge boson is referred to as the νR-philic Z′. Despite the absence of direct gauge couplings to ordinary matter at tree level, loop-induced couplings of the νR-philic Z′ via left-right neutrino mixing can be responsible for its experimental accessibility. An important feature of the νR-philic Z′ is that its couplings to neutrinos are generally much larger than its couplings to charged leptons and quarks, thus providing a particularly interesting scenario for future neutrino experiments such as DUNE to probe. We consider two approaches to probe the νR-philic Z′ at DUNE near detectors via (i) searching for Z′ decay signals, and (ii) precision measurement of elastic neutrino-electron scattering mediated by the Z′ boson. We show that the former will have sensitivity comparable to or better than previous beam dump experiments, while the latter will improve current limits substantially for large neutrino couplings.