Related papers: J/psi dissociation and Adler's theorem
We present numerical results for the dissociation cross sections of ground-state, orbitally- and radially-excited charmonia in collisions with light mesons. Our results are derived using the nonrelativistic quark model, so all parameters…
We construct a chiral Lagrangian containing besides the usual pion field (pi) also its first radial excitation (pi'). The Lagrangian is derived by bosonization of a Nambu--Jona-Lasinio quark model with separable non-local interactions, with…
A nonlinear realization of SU(2) chiral symmetry spontaneous breaking approach is developed in the composite operator formalism. A Lagrangian including quark, gluon and Goldstone boson degrees of freedom of the chiral quark model is…
The status of chiral perturbation theory in the meson sector is illustrated with several topical examples. The longtime discrepancy between theory and experiment for the charged pion polarizabilities has now been resolved in favour of the…
We construct the most general low-energy effective lagrangian including local parity violating terms parametrized by an axial chemical potential or chiral imbalance $\mu_5$, up to ${\cal O}(p^4)$ order in the chiral expansion for two light…
We show on the basis of an effective theory of QCD that a wide variety of observables in the hadron world is governed by the chiral symmetry together with an interplay between the axial anomaly and the explicit symmetry breaking due to the…
We construct a three flavor chiral Lagrangian of pseudoscalars and vectors with special emphasis on the symmetry breaking terms. Comparing tree level two and three point functions with experiment allows us to first, fix the parameters of…
We calculate the decay rate of light scalar mesons, using a diquark chiral effective theory, recently proposed to describe exotic hadrons. In the effective theory the light scalar mesons are postulated to be bound states of diquark and…
It is shown, with the example of the experimentally known Adler function, that there is no matching in the intermediate region between the two asymptotic regimes described by perturbative QCD (for the very short-distances) and by chiral…
We construct an effective Lagrangian for the hadronic decays of a heavy excited $s$-wave-spin-one quarkonium into its ground state. We show that reasonable fits to the measured invariant mass spectra in the $J/\psi$ and $\Upsilon$ systems…
The possibility of the formation of a local parity breaking (LPB) in a quark-hadron medium is examined as a result of chiral symmetry violation, i.e, the appearance of difference between the average densities of right- and left-handed…
We analyze the decay modes of charmed mesons into two--pseudoscalars in a weak--gauged U(4)_L x U(4)_R chiral lagrangian model. The calculation is free of unknown parameters and only requires as inputs the masses of pseudoscalars and the…
The spontaneous breakdown of the chiral symmetry of the QCD Lagrangian ensures that $\pi\pi$ interactions are weak at low energies. How weak depends on the nature of explicit symmetry breaking. Measurements of $K_{e4}$ decays at DA$\Phi$NE…
The main aspects of chiral symmetry in QCD are presented. The necessity of its spontaneous breakdown is explained. Some low-energy theorems are reviewed. The role of chiral effective Lagrangians in the formulation and realization of chiral…
The chiral Lagrangian is a cornerstone of modern particle physics, offering a systematic and quantitative description of low-energy pions. Using tools from the modern scattering amplitudes program, we show that consistent multiparticle…
We study J/$\psi$ propagation in hot hadronic matter using a four-flavor chiral Lagrangian to model the dynamics and using QCD sum rules to model the finite size effects manifested in vertex interactions through form factors. Charmonium…
By bosonization of an extended NJL model we derive an effective meson theory which describes the interplay between chiral symmetry and heavy quark dynamics. This effective theory is worked out in the low-energy regime using the gradient…
We report on a novel scheme based on the chiral Lagrangian. It is used to analyze pion-nucleon scattering, pion photoproduction, and nucleon Compton scattering. Subthreshold partial-wave amplitudes are calculated in chiral perturbation…
We consider the production of charmonium by $D\bar D$ annihilation during the mixed and hadronic phase of Pb-Pb collision at LHC energy. The calculations for secondary $J/\psi$ and $\psi^,$ production are performed within a kinetic model…
An effective lagrangian incorporating both chiral and heavy quark symmetries and describing the low momentum interactions of heavy mesons and light scalar and vector resonances is presented. Using some available data and assuming nearest…