arXiv subjects

Rubén Oncala

Publications and source records attributed to Rubén Oncala.

3 recordsLinked to original sources

arXiv2025

Hybrid to Quarkonia transitions

Hybrid quarkonia -exotic hadrons with explicit gluonic degrees of freedom- have gained increasing attention in hadron spectroscopy, particularly with the ongoing discovery of new XYZ mesons. In this work, we update the spectrum of heavy hybrid mesons in the charmonium and bottomonium sectors using the Born-Oppenheimer Effective Field Theory framework, by incorporating the latest lattice QCD results for hybrid static potentials. We refine earlier calculations and analyze allowed transitions from hybrids to conventional quarkonia, including both spin-conserved and spin-flip decays. We carry out a comprehensive error analysis and discuss the reliability of our results. We compare them to experimental data of the Particle Data Group, which allows us to identify hybrid candidates among the observed XYZ states. We provide hybrid or quarkonium interpretations for nearly all heavy isospin-zero mesons observed and incorporate new hybrid candidates.

hep-ph↗

arXiv2017

Heavy Quarkonium Hybrids: Spectrum, Decay and Mixing

We present a largely model independent analysis of the lighter Heavy Quarkonium Hybrids based on the strong coupling regime of Potential Non-Relativistic QCD (pNRQCD). We calculate the spectrum at leading order, including the mixing of static hybrid states. We use potentials that fulfill the required short and long distance theoretical constraints and fit well the available lattice data. We argue that the decay width to the lower lying Heavy Quarkonia can be reliably estimated in some cases, and provide results for a selected set of decays. We also consider the mixing with Heavy Quarkonium states. We establish the form of the mixing potential at $O(1/m_Q)$, $m_Q$ being the mass of the heavy quarks, and work out its short and long distance constraints. The weak coupling regime of pNRQCD and the effective string theory of QCD are used for that goal. We show that the mixing effects may indeed be important and produce large spin symmetry violations. Most of the isospin zero XYZ states fit well in our spectrum, either as a Hybrid or standard Quarkonium candidates.

hep-ph↗

arXiv2016

Heavy Hybrids: decay to and mixing with Heavy Quarkonium

We report on a recent QCD based research on hybrid mesons containing $c\bar c$ or $b\bar b$ quarks. We present results for the spectrum, the decay widths to heavy quarkonium, and the role of mixing with the latter. We point out that mixing with heavy quarkonium provides a potentially large source of spin symmetry breaking. We identify candidates to hybrid mesons among the so called XYZ states in the charmonium and bottomonium spectrum.

hep-ph↗