Heavy hybrid decays in a constituent gluon model

A constituent gluon model that is informed by recent lattice field theory is developed. The model is then used to compute hybrid strong decay widths that could be useful for the GlueX Collaboration at Jefferson Lab and the PANDA Collaboration at FAIR. Commensurately, forthcoming data from GlueX and PANDA will test the model. Widths tend to be typical of charmonia, except for those of the lightest hybrid S-wave multiplet. Selection rules, extensions, limitations, and applications are discussed.Facultad de Ciencias Exacta

Heavy Hadronic Molecules Coupled with Multiquark States

We investigate the hidden-charm pentaquarks as a Λc͞D⁽*⁾ – Σc⁽*⁾͞D⁽*⁾ hadronic molecule coupling to a compact five-quark state. The coupling to the compact state leads to an hadron short-range interaction generating an attraction. In addition, the one pion exchange potential (OPEP) as a long-range interaction is introduced by the Lagrangians satisfying the chiral and heavy quark spin symmetries. The OPEP has been known as a driving force to bind atomic nuclei, where the tensor term leading the coupled-channel effect generates a strong attraction. The mass degeneracy of heavy hadrons due to the heavy quark spin symmetry enhances the OPEP derived by the πD⁽*⁾͞D⁽*⁾ and πΣc⁽*⁾Σc⁽*⁾ couplings. Introducing those interactions, we consistently explain the masses and widths of the Pc states reported by LHCb in 2019. The short range interaction has a dominant role to determine the energy-level structures, while the OPEP tensor term does the decay width.Facultad de Ciencias Exacta

P_c pentaquarks with chiral tensor and quark dynamics

We investigate the hidden-charm pentaquarks as superpositions of Λc͞D⁽*⁾ ðÞ and Σc⁽*⁾͞D⁽*⁾(isospin I = 1/2) meson-baryon channels coupled to a uudc͞c compact core by employing an interaction satisfying the heavy quark and chiral symmetries. Our model can consistently explain the masses and decay widths of Pc⁺(4312), Pc⁺(4440) and Pc⁺(4457) with the dominant components of Σc͞D and Σc͞D* with spin-parity assignments Jᴾ =1/2⁻, 3/2⁻ and 1/2⁻, respectively. We analyze basic properties of the Pc’s such as masses and decay widths, and find that the mass ordering is dominantly determined by the quark dynamics while the decay widths by the tensor force of the one-pion exchange.Facultad de Ciencias Exacta

The Ω_c-puzzle solved by means of quark model predictions

The observation of five Ωc = ssc states by LHCb [Aaij et al. Phys. Rev. Lett. 118, 182001; (2017)] and the confirmation of four of them by Belle [Yelton et al. Phys. Rev. D 97, 051102; (2018)], may represent an important milestone in our understanding of the quark organization inside hadrons. By providing results for the spectrum of Ωc baryons and predictions for their Ξc⁺ K⁻ and Ξ'c⁺ K⁻ decay amplitudes within an harmonic oscillator based model, we suggest a possible solution to the Ωc quantum number puzzle and we extend our mass and decay width predictions to the Ωb states. Finally, we discuss why the set of Ωc(b) baryons is the most suitable environment to test the validity of three-quark and quark–diquark effective degrees of freedom.Facultad de Ciencias Exacta