Measurements of the mass and width of the eta_c using psi' -> gamma eta_c

BESIII Collaboration, M. Ablikim, M. N. Achasov +332

The mass and width of the lowest lying S-wave spin singlet charmonium state, the eta_c, are measured using a data sample of 1.06x10^8 psi' decays collected with the BESIII detector…