J/ψabsorption byπandρmesons in a meson exchange model with anomalous parity interactions

Abstract

We reanalyze the dissociation process of the J/ψ by π and ρ mesons into D +D, D * +D, D +D * , and D * +D * within a meson exchange model. In addition to the dissociation mechanisms considered in the literature, we consider anomalous parity interactions, whose couplings are constrained by heavy quark spin symmetry and phenomenology. This opens new dissociation channels and adds new diagrams in the previously considered processes. Compared to the previous results, we find that these new additions have only a minor effect on the ρ + J/ψ total inelastic cross section, but reduce the one for π + J/ψ by about 50 % near the threshold.

Hadronic form factors and theJ/ψsecondary production cross section: An update

“…In previous studies doing the same kind of comparison, as for example in Ref. [17], the introduction of form factors reduced the cross sections by factors ranging between 20 and 50 depending on the channel. In that work, the form factor was the same for all vertices and the cutoff, not known, was estimated to be between 1 and 2 GeV.…”

“…The quartic vertex couplings could not be obtained with QCDSR, and we used the prescription given in Ref. [17],…”

“…Also considered was quark exchange between two (hadronic) bags [14,15]. The most explored approach has been the meson exchange mechanism [16][17][18][19][20]. In our opinion, the most reliable calculations of σ J/ψ−π were done with QCD sum rules [21].…”

Charmonium absorption in the meson-exchange model

“…Without employing form factors at the interaction vertices, the resulting cross section for J/ψ absorption by pion is about 0.3 mb at the kinetic energy of 0.8 GeV. In later more complete studies, both threevector-meson and four-point couplings are also included in the interaction Lagrangians [10,11,12,13,14], and much larger cross sections are obtained for J/ψ absorption by light hadrons. In contrast to the perturbative QCD approach and the quark-interchange model, form factors are needed at the interaction vertices in the meson-exchange model to take into account the finite size of hadrons.…”

“…With this effective Lagrangian, various reactions involving charmed mesons and J/ψ have been studied. These include charmed meson scattering such as πD ↔ ρD * [16,17] and charmonium absorption such as πψ → DD * [9,10,11,12,13,14]. Extension of the effective hadronic Lagrangian to SU(5) flavor symmetry allows one to study also Υ absorption by hadrons [18].…”