In-medium decay widths of hidden and open charm vector mesons in a field theoretic model for composite hadrons

Abstract

We calculate the decay widths of the charmonium states, J/ψ, ψ(3686) and ψ(3770), to DD pairs, as well as the decay width of D * → Dπ, in isospin asymmetric strange hadronic matter, using a field theoretical model for composite hadrons with quark constituents. For this purpose we use the quark antiquark pair creation term of the free Dirac Hamiltonian written in terms of the constituent quark field operators, and use explicit charmonium, D,D, D * and π states to evaluate the matrix elements for the charmonium as well as D * decay amplitudes. The medium modifications of the partial decay widths of charmonium to DD pair, arising from the mass modifications of the D(D) and the charmonium states calculated in a chiral effective model, are also included. The results of the present investigations are then compared with the decay widths computed earlier, in a model using light quark pair creation in 3 P 0 state. As in 3 P 0 model, the decay amplitude in the present model is multiplied with a strength parameter for the light quark pair creation, which is fitted from the observed vacuum decay width. The effects of the isospin asymmetry, the strangeness fraction of the hadronic matter on the masses of the charmonium states and D(D) mesons and hence on the decay widths, have also been studied. The isospin asymmetry effect is observed to be dominant for high densities, leading to appreciable difference in the decay channels of the charmonium to D + D − and D 0D0 pairs. The decay width of D * → Dπ in the hadronic matter has also been calculated within the composite quark model in the present work, accounting for the medium modifications of the D and D * masses. The density modifications of the charmonium states and D(D * ) mesons, which are observed to be appreciable at high densities, will be of relevance in the compressed baryonic matter (CBM) experiments at the future facility of FAIR, GSI, where charmed hadrons will be produced by annihilation of antiprotons on nuclei. The interactions of the charmonium states and D(D * ) with the nuclear medium could lead to the possiblility of the formation of exotic bound states of the nuclei with the (excited) charmonium states as well as with D(D

Charmonia decay widths in magnetized matter using a model for composite hadrons

“…We use a field theoretical model for composite hadrons with quark/antiquark constituents [30][31][32] to study the charmonium decay widths to D D in isospin asymmetric nuclear matter in the presence of a magnetic field. The model has been used to investigate these charmonium decay widths in hadronic matter in the absence of a magnetic field [28]. With explicit construc-tions of the charmonium state and the open charm mesons, the decay width is calculated using the quark antiquark pair creation term of the free Dirac Hamiltonian for constituent quark field [28].…”

“…The model has been used to investigate these charmonium decay widths in hadronic matter in the absence of a magnetic field [28]. With explicit construc-tions of the charmonium state and the open charm mesons, the decay width is calculated using the quark antiquark pair creation term of the free Dirac Hamiltonian for constituent quark field [28]. The model for the composite hadrons with quark constitutents has been described in Appendix A.…”

“…As the mass of proton is much larger as compared to the mass of the electron, the binding energy contribution from the electron is µ me × BE ≃ BE of hydrogen atom, and the contribution from the proton is µ mp × BE, which is negligible as compared to the total binding energy of hydrogen atom, since m p >> m e . With this assumption, the binding energies of the heavy-light mesons, e.g., D and ( D) mesons [28] and, B B mesons [34], mostly arise from the contribution from the light quark (antiquark).…”

“…The charmonium masses are calculated from the medium modification of a scalar dilaton field which mimics the gluon condensates of QCD [4,5,21] and the in-medium masses of the open charm (D, D) mesons, are computed from their interactions with the baryons and scalar mesons [4,5,18] in the (magnetized) hadronic medium. The in-medium decay widths of the charmonium states to D D at zero magnetic field, have been studied using a model with light quark pair created in the 3 P 0 state [5,[25][26][27], as well as, using a field theoretical model with composite hadrons [28]. The results of the present investigation of the charmonium decay widths in magnetized nuclear matter calculated using the model for composite hadrons are compared with the results obtained using the 3 P 0 model [29].…”

Decay widths of bottomonium states in matter: A field theoretic model for composite hadrons

“…gluon condensates calculated from the dilaton field in the hadronic medium, within the effective hadronic model [21]. Using the medium changes of the masses of the charmonium states, and, the D andD mesons, the partial decay widths of the charmonium states to DD have been investigated using 3 P 0 model [21] as well as using the model for composite hadrons with quark and antiquark constituents [30]. In Ref.…”