  The shapes of the inclusive photon spectra in the processes $\Jp \to \gamma
X$ and $\Up \to \gamma X$ have been analysed using all available experimental
data.
  Relativistic, higher order QCD and gluon mass corrections were taken into
account in the fitted functions. Only on including the gluon mass corrections,
were consistent and acceptable fits obtained. Values of
$0.721^{+0.016}_{-0.068}$ GeV and $1.18^{+0.09}_{-0.29}$ GeV were found for the
effective gluon masses (corresponding to Born level diagrams) for the $\Jp$ and
$\Up$ respectively. The width ratios $\Gamma(V \to {\rm hadrons})/\Gamma(V \to
\gamma+ {\rm hadrons}) V=\Jp, \Up$ were used to determine $\alpha_s(1.5 {\rm
GeV})$ and $\alpha_s(4.9 {\rm GeV})$. Values consistent with the current world
average $\alpha_s$ were obtained only when gluon mass correction factors,
calculated using the fitted values of the effective gluon mass, were applied. A
gluon mass $\simeq 1$ GeV, as suggested with these results, is consistent with
previous analytical theoretical calculations and independent phenomenological
estimates, as well as with a recent, more accurate, lattice calculation of the
gluon propagator in the infra-red region.
