Related papers: Parity violating pion electroproduction off the nu…
The lower excitation spectrum of the nucleon and $\Delta$ is calculated in a relativistic chiral quark model. Contributions of the second order self-energy and exchange diagrams due-to pion fields to the mass spectrum of the SU(2) baryons…
Large momentum transfer reactions such as pion production represent the frontier of Chiral Perturbation Theory and must be understood before more complex reactions can be considered. Pion production is also interesting in its own right, one…
We investigate neutrino induced one pion production on nucleons. The elementary neutrino--nucleon cross section is calculated as the sum of the leading Delta pole diagram and several background diagrams obtained within the non-linear sigma…
A newly-proposed parity-violating nucleon-nucleon interaction based on effective field theory is studied in this work. It is found that at low energy, i.e., E_lab less than 90 MeV for 1S0-3P0 transitions and E_lab less than 40 MeV for…
We review our recent work on Chiral Lagrangians out of thermal equilibrium, which are introduced to analyse the pion gas formed after a Relativistic Heavy Ion Collision. Chiral Perturbation Theory is extended by letting $\fpi$ be time…
The strange particle production induced by (anti)neutrino off nucleon has been studied for $|\Delta S|=0$ and $|\Delta S|=1$ channels. The reactions those we have considered are for the production of single kaon/antikaon, eta and associated…
Using a relativistic effective Lagrangian at the hadronic level, near-threshold $\omega$ and $\phi$ meson productions in proton proton ($pp$) collisions, $p p \to p p \omega/\phi$, are studied within the distorted wave Born approximation.…
We complete our derivation of upper limits on the CP violating $\eta\pi\pi$ and $\eta'\pi\pi$ couplings from an analysis of their two-loop contributions to the neutron electric dipole moment (nEDM). We use a phenomenological Lagrangian…
We investigate parity violation in neutron-nucleus collisions at very low energy region $(E \leq 100 \ev)$, including resonance states. We use the coupled channel formalism for resonances with radiative emission. The parity mixing between…
Polarized beam gamma p Compton scattering provides a theoretically clean way to extract the isovector parity violating pion-nucleon coupling constant $h_{\pi NN}^{(1)}$. This channel is more tractable experimentally than the recently…
We investigate parity-violating asymmetries in polarized n p radiative capture, and deuteron electro-disintegration in quasi-elastic kinematics, using the DDH model for the parity-violating nucleon-nucleon interaction. We find dramatic…
We calculate the energy dependence of the asymmetry in the cross sections for circularly polarized photons on an unpolarized deuteron target in $d\vec{\gamma} \to np$ in pionless effective field theory. By matching the parity-violating…
Extending a recent suggestion for hyperon form factors to the nucleon case, dispersion theory is used to relate the low-energy vector-isovector form factors of the nucleon to the pion vector form factor. The additionally required input,…
The Wess-Zumino-Witten structure is supplemented by a simple vector-meson Lagrangian where the vector mesons are described by antisymmetric tensor fields. With the \rho-\omega-\pi{} coupling as the only parameter in the sector of odd…
First calculations for spin-dependent observables of the reactions $pp \to pp\pi^0$, $pp \to pn\pi^+$ and $pp \to d\pi^+$ near threshold are presented, employing the J\"ulich model for pion production. The influence of resonant (via the…
Parity-violating (pv) effects in inclusive hadron and jet productions in high energy hadron-hadron collisions are analyzed. Such effects arise from the interference between strong and weak amplitudes. This interference gives rise to a…
The hadronic tau decay $\tau^- \to \nu_\tau \eta \pi^- \pi^0$ occurs through V-A weak current. In this decay mode, the vector current contribution is intrinsic parity violating and the axial current contribution is G parity violating. The…
We study near-threshold $\eta$ meson production in $pp$ collisions within an effective Lagrangian approach combined with the isobar model, by allowing for the various intermediate nucleon resonances due to the $\pi$, $\eta$, and…
Starting with the general principles of global and local symmetries, the effective pion-nucleon lagrangian, essentially non-linear in pion field, to describe the non-strange hadrons low-energy electro-weak transitions is developed. We…
Large parity violating longitudinal single spin asymmetries A^{e^-}_L= -0.86^{+0.14}_{-0.30} and A^{e^+}_L= 0.88^{+0.12}_{-0.71} are observed for inclusive high transverse momentum electrons and positrons in polarized pp collisions at a…