Muon capture on light isotopes measured with the Double Chooz detector

Using the Double Chooz detector, designed to measure the neutrino mixing angle ?13, the products of µ- capture on C12,C13,N14, and O16 have been measured. Over a period of 489.5 days, 2.3×106 stopping cosmic µ- have been collected, of which 1.8×105 captured on carbon, nitrogen, or oxygen nuclei in the inner detector scintillator or acrylic vessels. The resulting isotopes were tagged using prompt neutron emission (when applicable), the subsequent ß decays, and, in some cases, ß-delayed neutrons. The most precise measurement of the rate of C12(µ-,?)B12 to date is reported: 6.57-0.21+0.11×103s-1, or (17.35-0.59+0.35)% of nuclear captures. By tagging excited states emitting ?s, the ground state transition rate to B12 has been determined to be 5.68-0.23+0.14×103s-1. The heretofore unobserved reactions C12(µ-,?a)Li8,C13(µ-,?na)Li8, and C13(µ-,?n)B12 are measured. Further, a population of ßn decays following stopping muons is identified with 5.5s significance. Statistics limit our ability to identify these decays definitively. Assuming negligible production of He8, the reaction C13(µ-,?a)Li9 is found to be present at the 2.7s level. Limits are set on a variety of other processes.