Nucleon Decay into Dark Sector

Understand

A sub-GeV dark sector fermion X can have baryon number violating interactions induced by high scale physics, leading to nucleon decay into X + meson and neutron -> X + photon.

• Such processes can mimic standard search modes containing a neutrino, but have different kinematics and may have escaped detection.
• If a dark force mediated by a light vector Z_d acts on X, depending on parameters, neutron -> X + Z_d can be important.
• In typical scenarios, Z_d decays into l^+l^-, where l=e, mu, with order unity branching fraction.