Analysis of the exclusive interaction νμ−12C→μ−12 N near threshold

We report on the first observation of νμ‐induced nuclear transitions νν12C→μ−12N. From a sample of νμ interactions on carbon near the muon production threshold, events with a 12N nucleus in the final state were isolated by observing the subsequent beta decay of the 12N ground state. This exclusive process represents (31+12)% of the inclusive cross section for νμ12C→μ−X. (Theoretical estimates of this fraction suggest a maximum of only 3%.) The muon kinetic energy for both the inclusive and exclusive channels was also measured. Using the muon kinetic energy distribution we identify the contributions to the cross sections from the 12N* and compare our results to theory.