  Stimulated by the experimental observation, made by the E760 Collaboration at
Fermilab, of the $^1\!P_1$ state of charmonium resonantly formed in $p\,\bar p$
annihilation, we perform a calculation of the decay width for the $^1\!P_1\to
p\,\bar p$ process. To this end, we employ a phenomenological model which adds
constituent quark mass corrections to the usual massless QCD models for
exclusive processes. For massless models, in fact, the process under
consideration is forbidden by the so-called helicity selection rules, while it
is allowed in our extended model. We find $\Gamma(^1\!P_1\to p\,\bar p)$ to be
in the range $1-10$ eV. We also compare our results with previous, indirect
estimates, based on QCD multipole expansion models.
