Masses and other parameters of the light hadrons

Abstract

The masses and static parameters of the light hadrons (the pseudoscalar and vector meson nonets and the baryon octet and decuplet) are calculated using the bag model. The effects of quark kinetic energy, bag energy, strange-quark mass, colored-gluon exchange in lowest order, and energy associated with certain quantum fluctuations are included. These are parameterized by four constants which have fundamental significance and do not change from multiplet to multiplet. The fit to the spectrum is good. The ordering of all the states is given correctly. The intramultiplet splittings are very accurate for the baryon decuplet and reasonably good for the other multiplets. The isosinglet pseudoscalar mesons $\ensuremath{\eta}$ and ${\ensuremath{\eta}}^{\ensuremath{'}}$ are treated separately in light of the special role that gluon intermediate states play in these states. Magnetic moments, weak decay constants, and charge radii are calculated. Where comparison with experiment is possible, we generally obtain improvement over the naive quark model. It is shown that exotic baryons do not exist as narrow resonances in this approximation to the bag theory.