ﻻ يوجد ملخص باللغة العربية
The production of pseudo scalar, Eeta, Eta-prime, and vector, Omega, Rho, Phi, mesons in NN collisions at threshold-near energies is analyzed within a covariant effective meson-nucleon theory. It is shown that a good description of cross sections and angular distributions, for vector meson production, can be accomplished by considering meson and nucleon currents only, while for pseudo scalar production an inclusion of nucleon resonances is needed. The di-electron production from subsequent Dalitz decay of the produced mesons, $etato gamma gamma^* togamma e^+e^-$ and $omegato pigamma^*to pi e^+e^-$ is also considered and numerical results are presented for intermediate energies and kinematics of possible experiments with HADES, CLAS and KEK-PS. We argue that the transition form factor $omegato gamma^*pi$ as well as $etato gamma^*gamma$ can be defined in a fairly model independent way and the feasibility of an experimental access to transition form factors is discussed.
The hadronic decays eta, eta-prime -> 3 pi and eta-prime -> eta pi pi are investigated within the framework of U(3) chiral effective field theory in combination with a relativistic coupled-channels approach. Final state interactions are included by d
Various decays of eta and eta-prime are investigated within the framework of U(3) chiral effective field theory in combination with a relativistic coupled-channels approach. Final state interactions are included by deriving s- and p-wave interaction
We determine the masses, the singlet and octet decay constants as well as the anomalous matrix elements of the $eta$ and $eta^prime$ mesons in $N_f=2+1$ QCD@. The results are obtained using twenty-one CLS ensembles of non-perturbatively improved Wils
The PHENIX experiment at the Relativistic Heavy Ion Collider measured $pi^0$ and $eta$ mesons at midrapidity in U$+$U collisions at $sqrt{s_{_{NN}}}=192$ GeV in a wide transverse momentum range. Measurements were performed in the $pi^0(eta)rightarrow
We consider the chiral Lagrangian with a nonet of Goldstone bosons and a nonet of light vector mesons. The mixing between the pseudoscalar mesons eta and eta-prime is taken into account. A novel counting scheme is suggested that is based on hadrogene