Measurement of the absolute branching fraction of the inclusive decay ?-c -? n- plus X

Based on e+e- collision data corresponding to an integrated luminosity of 4.5 fb-1 collected at the center-of-mass energies between 4.600 and 4.699 GeV with the BESIII detector at BEPCII, the absolute branching fraction of the inclusive decay over bar ? - c & RARR; n over bar + X, where X refers to any possible final state particles, is measured. The absolute branching fraction is determined to be B( over bar ?-c & RARR; n over bar + X) = (32.4 + 0.7 + 1.5)%, where the first uncertainty is statistical and the second systematic. Assuming CP symmetry, the measurement indicates that about one fourth of ?+ c ( over bar ?-c) decay modes with a neutron (an antineutron) in the final state have not been observed.

Automated summary

Based on data collected at the BESIII detector at BEPCII, the absolute branching fraction of an inclusive decay process in e+e- collisions is measured. The results suggest that around one fourth of certain decay modes involving a neutron or antineutron have not been observed.