A study of wrong-sign single muon production inv μ-nucleon interaction

We report on a search forv μ-induced events where the single emerging muon carries lepton number opposite that of the incident neutrino. The rate and kinematic quantities of the candidate events are compared with known backgrounds from\(\bar v_\mu \)-induced charged current interactions and ν-induced interactions that produce dileptons. We derive an upper limit on the rate of wrong-sign single muon production relative to the rate ofv μ charged current interactions to be 1.6×10−4 fory 0.5 (90% CL). These upper limits enable us to constrain exotic sources of wrong-sign muons such as the charm component of the nucleon sea, flavor changing neutral currents and lepton number violating processes. Finally, the rate and kinematic properties of these events are compared with those of the neutrino-induced opposite-sign dimuon events.