相关论文: Scalar Meson Photoproduction
The radiative decays of the phi meson are known to be a good source of information about the a0(980) and f0(980) scalar mesons. We discuss these decays starting from a non-linear model Lagrangian which maintains the (broken) chiral symmetry…
The scalar mesons are established for a long time, but their nature is still an open question. In this paper, we investigate the potential of categorizing their $SU(3)_f$ representations via $J/\psi\to SV$ and $\gamma S$, offering a…
We calculate diffractive photo- and leptoproduction of $\rho$-, $\rho'$- and $\rho''$-mesons. The incoming photon dissociates into a $q\bar{q}$-dipole which scatters on the nucleon and transforms into a vector meson state. The scattering…
The process of exclusive vector meson production (gamma gamma to J/psi rho^0) is studied for almost real photons. This process may be reduced to photoproduction of J/psi off the rho^0 meson. We discuss the possibility of extracting the…
The $\rho\rho$ scattering has been studied by two groups which both claimed a dynamical generated scalar meson, most likely to be $f_0(1370)$. Here we investigate the influence of coupled-channels of pseudoscalar mesons, i.e., $\pi\pi$ and…
The study of hyperon resonances has entered a new era of precision with advent of high-statistics photoproduction data from the CLAS detector at Jefferson Lab. These data have multi-particle final states, allowing clean identification of…
We study photoproduction of rho mesons in a model of hidden local symmetry. The rho meson is introduced as a hidden gauge boson and a phenomenological rho meson-nucleon Lagrangian is constructed respecting chiral symmetry. It is shown that…
Two pion effective mass and helicity angle distributions in the charged B-meson decays into three charged pions are studied. The weak decay amplitudes are calculated in the framework of the QCD factorization approximation. The strong…
The two-photon decay widths of scalar mesons \sigma(600), f_0(980) and a_0(980) are calculated in framework of the local Nambu-Jona-Lasinio model. The contributions of the quark loops (Hartree-Fock approximation) and the meson loops (next…
Positivity constraints have proved to be important for spin observables of exclusive reactions involving polarized initial and final particles. Attention is focused in this note on the photoproduction of pseudoscalar mesons from spin 1/2…
Primakoff effect offers us with a way to determine the radiative decay width of pseudo-scalar mesons when they are photo-produced in the electromagnetic field of hadronic systems. Taking advantage of recent developments in the Regge…
We report on the results of the first measurement of exclusive $f_0(980)$ meson photoproduction on protons for $E_\gamma=3.0 - 3.8$ GeV and $-t = 0.4-1.0$ GeV$^2$. Data were collected with the CLAS detector at the Thomas Jefferson National…
Properties of scalar-isoscalar mesons are analysed using separable interactions in three decay channels: pion-pion, kaon-antikaon and an effective 2pion-2pion. We obtain different solutions by fitting various data on the pion-pion and…
A consistent description of $\sigma(500)$ meson effects in $\rho^0\to\pi^0\pi^0\gamma$ and $\pi^+\pi^-\gamma$ decays is proposed in terms of reasonably simple amplitudes which reproduce the expected chiral-loop behaviour for large…
We calculate low-energy meson decay processes and pion-pion scattering lengths in a globally chirally invariant two-flavour linear sigma model exploring the quark content of the scalar mesons f(0)(600) and a(0)(980), as well as f(0)(1370)…
The pion scalar form factor along with all existing S-wave iso-scalar $\pi\pi$-scattering phase shift data in the elastic region up to $1 {\rm GeV}^2$ are applied for a determination of the $f_0(500)$ and $f_0(980)$ meson parameters…
Inclusive production of the f_0(980), f_2(1270) and \phi(1020) resonances has been studied in a sample of 4.3 million hadronic Z^0 decays from the OPAL experiment at LEP. A coupled channel analysis has been used for the f_0 in simultaneous…
Incoherent photoproduction of eta-mesons on the deuteron is considered. The main attention is paid to the region above the S11(1535) resonance where rather narrow resonance like structure in the total cross section extracted for gamma n ->…
It is presented a critical consideration of all unusual properties of the scalar a_0(980) and f_0(980)-mesons in the four-quark, two-quark and molecular models. The arguments are adduced that the four-quark model is more preferable. It is…
In the last years much work has been done to learn about the properties of the $\rho$-meson in nuclear matter. In a calculation of the in-medium spectralfunction of the $\rho$ we find that it is strongly modified by baryonic resonances,…