Pentaquark ${\Theta }^{+}$ in nuclear matter and ${\Theta }^{+}$ hypernuclei

Abstract

We study the properties of the ${\Theta }^{+}$ in nuclear matter and ${\Theta }^{+}$ hypernuclei within the quark mean-field (QMF) model, which has been successfully used for the description of ordinary nuclei and $\Lambda$ hypernuclei. With the assumption that the non-strange mesons couple only to the $u$ and $d$ quarks inside baryons, a sizable attractive potential of the ${\Theta }^{+}$ in nuclear matter is achieved as a consequence of the cancellation between the attractive scalar potential and the repulsive vector potential. We investigate the ${\Theta }^{+}$ single-particle energies in light, medium, and heavy nuclei. More bound states are obtained in ${\Theta }^{+}$ hypernuclei in comparison with those in $\Lambda$ hypernuclei.

Comments: 16 pages, 5 figures