Constituent quark model study of the meson spectra

Abstract

The qq spectrum is studied in a generalized constituent quark model constrained in the study of the N N phenomenology and the baryon spectrum. An overall good fit to the available experimental data is obtained. A detailed analysis of all sectors from the light-pseudoscalar and vector mesons to bottomonium is performed paying special attention to the existence and nature of some non well-established states. These results should serve as a complementary tool in distinguishing conventional quark model mesons from glueballs, hybrids or multiquark states.

Possible interpretation of theZb(10610) andZb(10650) in a chiral quark model

“…(3) that cannot be obtained from the usual one-loop expression of the running coupling constant because it diverges when Q → Λ QCD . Hence an effective scale-dependent strong coupling constant [18] is taken as…”

“…[18] due to its non-strange nature. The strange scalar meson (with large mass) exchange is not taken into account in the present work because of its small effect.…”

“…The above model is denoted as ChQM1. To testing the effect of σ-exchange between the lightest and strange quark or strange quark pairs, and long-range color screening on the binding energy of the molecular states, the Salamanca version of the chiral quark model [18], which is referred as ChQM2, is also employed here. The screened confinement interaction in this model is…”

“…To study the mass spectrum of above possible exotic states, two types of chiral quark models (ChQM) [18] are employed in this work. The numerical method, which is able to provide almost exact solutions, is very important in the study of few-body systems.…”

Docc¯nn¯bound states exist?

“…It was later on generalized to all flavor sectors giving a reasonable description of the meson [39] and baryon spectra [40]. The possible existence of four-quark states within this model has also been addressed [25,27,28].…”