The Pentaquark Candidates in the Dynamical Diquark Picture

Abstract

Starting with the dynamical picture of the exotic $c\bar{c}$-containing states $XYZ$ as the confinement-induced hadronization of a rapidly separating pair of a compact diquark and antidiquark, we describe the pentaquark candidates $P_c^{+}(4380)$ and $P_c^{+}(4450)$ in terms of a confined but rapidly separating color-antitriplet diquark $cu$ and color-triplet "triquark" $\bar{c}(ud)$. This separation explains the relatively small $P_c^{+}$ widths, despite these 5-quark systems lying far above both the $J/\psi p$ and ${\Lambda }_c{\bar{D}}^{(\ast )0}$ thresholds. The $P_c^{+}$ states are predicted to form isospin doublets with neutral partners $P_c^0$.

Comments: 5 pages, 1 pdf figure, pdflatex. Version accepted by Phys. Lett. B