Precision measurements of charmonium states formed in<i>pp¯</i>annihilation

Fermilab experiment E-760 studies the resonant formation of charmonium states in proton-antiproton interactions using a hydrogen gas-jet target in the Antiproton Accumulator ring at Fermilab. Precision measurements of the mass and width of the charmonium states ${\mathrm{\ensuremath{\chi}}}_{\mathit{c}1}$,${\mathrm{\ensuremath{\chi}}}_{\mathit{c}2}$, a direct measurement of the \ensuremath{\psi}' width, and a new precision measurement of the J/\ensuremath{\psi} mass are presented.