We calculate decuplet contributions to the s-wave pseudoscalar meson octet-baryon scattering lengths to the third order in heavy baryon chiral perturbation theory (HBχPT). Using experimental pion-nucleon and kaon-nucleon scattering lengths as inputs, we determine low-energy constants and predict other meson-baryon scattering lengths. Numerically we consider three cases: (1) the case with only b...

Coherent ω photoproduction from nuclei and ω properties in nuclear matter. Abstract. The coherent ω-meson photoproduction from nuclei is proposed as a phenomenological method to evaluate the momentum dependence of ω-meson mass shift and width in nuclear matter. We analyze available data on un-separated coherent and incoherent ω-meson photoproduction from nuclei and extract the imaginary part of...

Using the local flavor SU(4) gauge invariance in the limit of vanishing vector meson masses, we extend our previous study of charm meson scattering cross sections by pion and rho meson, which is based only on the pseudoscalarpseudoscalar-vector meson couplings, to include also contributions from the couplings among three vector mesons and among four particles. We find that diagrams with light m...

We perform phenomenological applications of modified gluon propagators and running coupling constants in scattering processes in Quantum Chromodynamics (QCD). The modified forms of propagators and running coupling constant are obtained by non-perturbative methods. The processes investigated includes the diffractive ones – proton-proton elastic scattering, light vector meson photo-production and...

Chiral effective lagrangians may differ in their prediction of meson-nucleon scattering amplitudes off-meson-mass-shell, but must yield identical S-matrix elements. We argue that the effective meson mass in nuclear matter obtained from chiral effective lagrangians is also unique. Off-mass-shell amplitudes obtained using the PCAC choice of pion field must therefore not be viewed as fundamental c...