6533b7dbfe1ef96bd1270839

RESEARCH PRODUCT

η−η′-glueball mixing

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description

We have revisited glueball mixing with the pseudoscalar mesons in the MIT bag model scheme. The calculation has been performed in the spherical cavity approximation to the bag using two different fermion propagators, the cavity and the free propagators. We obtain probabilities of mixing for the $\ensuremath{\eta}$ at the level of 0.006%--2.0%, while for the ${\ensuremath{\eta}}^{\ensuremath{'}}$ one at the level of 0.6%--40%, depending on the choice of bag radius and, therefore, of the strong coupling constant. Our results differ from previous calculations. The origin of our difference stems from the treatment of the time integrations. The comparison of our calculation with experimental data, which is consistent with small $\ensuremath{\eta}\ensuremath{-}{\ensuremath{\eta}}^{\ensuremath{'}}\ensuremath{-}G$ mixing, implies that the pseudoscalar glueball is small, $R\ensuremath{\sim}0.5--0.6\text{ }\text{ }\mathrm{fm}$ and has a large mass, ${M}_{G}\ensuremath{\sim}2000--2500\text{ }\text{ }\mathrm{MeV}$.