How the "H-particle" unravels the quark dynamics

Abstract

It is shown that the short-range part of the Goldstone boson exchange interaction between the constituent quarks which explains baryon spectroscopy and the short-range repulsion in the NN system induces a strong short-range repulsion in the flavour-singlet state of the $\Lambda \Lambda$ system with $J^P=0^{+}$. It then suggests that a deeply bound H-particle should not exist. We also compare our approach with other models employing different hyperfine interactions between quarks in the nonperturbative regime of QCD.

Comments: 9 pages. Section, devoted to the numerical estimate of the "H-particle" channel with the Goldstone boson exchange model, is extended. Discussion on the possible role of instantons is esentially modified