相关论文: Further insights into the "$\rho\pi$ puzzle"
We study the $\eta$ transitions between $\psi(4040/4160)$ and $J/\psi$ by introducing charmed meson loops in an effective Lagrangian approach to enhance the decay amplitudes. The branching fractions $\mathcal{B}[\psi(4040) \to J/\psi \eta]$…
The production of pseudoscalar and scalar mesons pairs and bound states (positronium or pionium atoms) in high energy $\gamma\gamma$ collisions at high energies provided by photon or vector meson exchanges are considered. The vector…
We report the first measurement of the di-electron invariant mass dependent transition form factor in the electromagnetic Dalitz decay $J/\psi \to e^+e^- \pi^0$ using $(10087 \pm 44) \times 10^6$ $J/\psi$ events collected by the BESIII…
It is pointed out that the radiative decays of a $\phi$ meson, $\phirho$ and $\phiom$, receive dominant contributions from the pseudoscalar ($P = \eta, \eta^{'}$) exchanges. Using the vector meson dominance model, we find that $B (\phirho)…
We apply the light-cone technique to electroproduction reaction $ep\to e\pi^+n$ long considered as a means of measuring the electromagnetic form factor of the pion. We show that the interpretation of the long-standing puzzle of large…
We discuss recent HERA results on vector--meson electroproduction gamma*p -> Vp and demonstrate that universality of the initial and final state interactions responsible for the transition between the on- and off-mass shell states allows to…
The pseudoscalar quarkonia exclusive decays to light mesons still poses a challenge to the theoretical understanding of quarkonium properties in decay. In this work, we evaluate the processes of pseudoscalar heavy quarkonium decays into…
We evaluate the cross sections for the dissociation of $J/\psi$ and $\psi'$ by $\pi$ and $\rho$ at low collision energies, using the quark-interchange model of Barnes and Swanson. The dissociation cross section for $J/\psi$ by $\pi$ is…
We calculate the cross sections for reactions of the J/psi with light mesons. We also evaluate its finite temperature spectral function. We investigate separately the role of elastic and inelastic channels and we compare their respective…
Contributions of two-pseudoscalar and vector-pseudoscalar meson loops to the rho-omega mass splitting are evaluated in a covariant model based on studies of the Schwinger-Dyson equations of QCD. The role and importance of the different time…
Motivated by the planned measurements of the time-like electromagnetic proton form factors an exploratory study of the time-like electromagnetic pion form factor is presented in a formalism which describes mesons as Poincar\'e-invariant…
We determine the value of the \omega -\rho- \pi mesons coupling (g_{\omega\rho\pi}), in the context of the vector meson dominance model, from radiative decays, the \omega \rightarrow 3\pi decay width and the e^+e^- \rightarrow 3\pi cross…
We calculate the $B\to\pi,\rho$ transition form factors in the framework of perturbative QCD to leading power of $1/M_B$, $M_B$ being the $B$ meson mass. We explain the basic principle by discussing the pion electromagnetic form factor. It…
We show that all abnormal parity three-body meson interactions can be adequately described by quark loops, evaluated at zero external momentum, with couplings determined by $U(N_f)$ symmetry. We focus primarily on radiative meson decays…
In this work we propose mainly phenomenological and theoretical models that allow, together with the use of the available experimental data, the calculation of form factors (FFs) and decay amplitudes. We focus our attention firstly on the…
By an effective Lagrangian plus QCD sum-rule approach, we investigate the mass shift of the $J/\psi$ state in medium, in symmetric nuclear matter with zero and finite temperature, and cold strange matter. The in-medium mass of the $J/\psi$…
The properties of light vector mesons near 2.2 GeV remain poorly understood, impeding progress in mapping the higher-lying hadronic spectrum. Utilizing the newly released BESIII data on the Born cross sections for the process of $e^+ e^-…
It is shown that the diagonalization of the axial-vector -- pseudoscalar transitions in the effective meson Lagrangian in presence of electromagnetic interactions leads to a deviation from the vector meson dominance picture which usually…
In this article, we study the decays $\psi^{\prime}\to {J/\psi}\pi^+\pi^-$ and $\eta_c^{\prime}\to {\eta_c}\pi^+\pi^-$ by taking into account the chiral symmetry breaking effects, the final-state interactions and the heavy quark symmetry.…
A recent modeling study of brightness ratios for CO rotational transitions in gas typical of the diffuse ISM by Liszt found the role of H collisions to be more important than previously assumed. This conclusion was based on quantum…