Hyperons in nuclear matter

The chiral version of the QMC model, in which the effect of gluon and pion exchanges is included self-consistently, is applied to the hyperons in a nuclear medium. The hyperfine interaction due to the gluon exchange plays an important role in the in-medium baryon spectra, while the pion-cloud effect is relatively small. At the quark mean-field level, the $\Lambda$ feels more attractive force than the \Sigma or \Xi in matter.