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Gonzalez, P., Mathieu, V., & Vento, V. (2011). Heavy meson interquark potential. Phys. Rev. D, 84(11), 114008–7pp.
Abstract: The resolution of Dyson-Schwinger equations leads to the freezing of the QCD running coupling (effective charge) in the infrared, which is best understood as a dynamical generation of a gluon mass function, giving rise to a momentum dependence which is free from infrared divergences. We calculate the interquark static potential for heavy mesons by assuming that it is given by a massive One Gluon Exchange interaction and compare with phenomenologyical fits inspired by lattice QCD. We apply these potential forms to the description of quarkonia and conclude that, even though some aspects of the confinement mechanism are absent in the Dyson-Schwinger formalism, the spectrum can be reasonably reproduced. We discuss possible explanations for this outcome.
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Gonzalez, P. (2015). Charmonium description from a generalized screened potential model. Phys. Rev. D, 92(1), 014017–11pp.
Abstract: A generalized screened potential model (GSPM), recently developed to study the bottomonium spectrum, is applied to the calculation of charmonium masses and electromagnetic widths. The presence in the GSPM of more quark-antiquark bound states than in conventional nonscreened potential models, allows for the assignment of GSPM states to cataloged nonconventional J(++) charmonium resonances as well as for the prediction of new (noncataloged) J(++) states. The results obtained seem to indicate that a reasonable overall description of J(++) charmonium resonances is feasible.
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Bruschini, R., & Gonzalez, P. (2019). Radiative decays in bottomonium beyond the long wavelength approximation. Phys. Rev. D, 100(7), 074001–13pp.
Abstract: We revisit the nonrelativistic quark model description of electromagnetic radiative decays in bottomonium. We show that even for the simplest spectroscopic quark model the calculated widths can be in good agreement with data once the experimental masses of bottomonium states and the photon energy are properly implemented in the calculation. For transitions involving the lower lying spectral states this implementation can be easily done via the long wavelength approximation. For transitions where this approximation does not apply we develop a new method of implementing the experimental energy dependencies.
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Bruschini, R., & Gonzalez, P. (2020). Radiative decays in charmonium beyond the p/m approximation. Phys. Rev. D, 101(1), 014027–16pp.
Abstract: We analyze the theoretical description of radiative decays in charmonium. We use an elementary emission decay model to build the most general electromagnetic transition operator. We show that accurate results for the widths can be obtained from a simple quark potential model reasonably fitting the spectroscopy if the complete form of the operator is used instead of its standard p/m approximation and the experimental masses are properly implemented in the calculation.
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Bruschini, R., & Gonzalez, P. (2020). Diabatic description of charmoniumlike mesons. Phys. Rev. D, 102(7), 074002–19pp.
Abstract: We apply the diabatic formalism, first introduced in molecular physics, to the description of heavy-quark mesons. In this formalism the dynamics is completely described by a diabatic potential matrix whose elements can be derived from unquenched lattice QCD studies of string breaking. For energies far below the lowest open flavor meson-meson threshold, the resulting diabatic approach reduces to the well-known Born-Oppenheimer approximation where heavy-quark meson masses correspond to energy levels in an effective quark-antiquark potential. For energies close below or above that threshold, where the Born-Oppenheimer approximation fails, this approach provides a set of coupled Schrodinger equations incorporating meson-meson components nonperturbatively, i.e., beyond loop corrections. A spectral study of heavy mesons containing c (c) over bar with masses below 4.1 GeV is carried out within this framework. From it a unified description of conventional as well as unconventional resonances comes out.
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