Extensively applied to both light and heavy meson decay and standing as one of the most successful strong decay models is the 3 P0 model, in which qq pair production is the dominant mechanism. The pair production can be obtained from the non-relativistic limit of a microscopic interaction Hamiltonian involving Dirac quark fields. The evaluation of the decay amplitude can be performed by a diagrammatic technique for drawing quark lines. In this paper we use an alternative approach which consists in a mapping technique, the Fock-Tani formalism, in order to obtain an effective Hamiltonian starting from same microscopic interaction. An additional effect is manifest in this formalism associated to the extended nature of mesons: bound-state corrections. A corrected 3 P0 is obtained and applied, as an example, to b1 → ωπ and a1 → ρπ decays.

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In this paper, we propose the study of the photoproduction of charmoniumlike states in pp collisions at RHIC and LHC energies and estimate the rapidity distribution and total cross sections for the production of the exotic hadrons Yð3940Þ, Xð3915Þ, Zð4430Þ, and Z c ð3900Þ. We demonstrate that the experimental analysis of this process can provide complementary and independent checks on these states and help to understand their underlying nature.

In heavy ion collision simulations many hadron states and/or parton degrees of freedom are included in order to obtain the observables. Meson spectroscopy, for example, considers the 0 ++ meson as a mixture of q q and glue. This fact is usually not considered in heavy ion collision physics. In the present work we consider two extreme possibilities for the constitution of the 0 ++ meson, either as a pure glueball or as q qmeson. The scattering amplitude and cross-sections with constituent interchange are determined for the two situations. The comparison showed that the glueball-glueball elastic scattering cross-section for a color singlet state is between one to two orders of magnitude smaller than the corresponding q q state. The 2 ++ glueball-glueball interaction is also evaluated with similar behavior. Thus, glueball-glueball scattering is not very likely to introduce significant changes in heavy ion collision observables.

In this work we use a mapping technique to derive in the context of a constituent gluon model an effective Hamiltonian that involves explicit gluon degrees of freedom. We study glueballs with two gluons using the Fock–Tani formalism.