Related papers: Hypernuclear potentials and the pseudoscalar meson…
The 2H(p,n) charge exchange reaction at T_p=790 MeV is used to study the Delta(1232)-nucleon interaction in the Delta resonance excitation energy region. For the Delta-N potential, a meson exchange model is adopted where pi, rho, omega, and…
At finite density parity can be spontaneously broken in strong interactions with far reaching implications. In particular, a time-dependent pseudoscalar background would modify QED by adding a Chern-Simons term to the lagrangian. As a…
The main open problem in the physics of Lambda-hypernuclei is the lack of a sound theoretical interpretation of the large experimental values for the ratio G_n/G_p. To approach the problem, we have incorporated a Lambda N-> nN…
Motivated by the success of models based on chiral symmetry in NN interactions we investigate self-interacting scalar, pseudoscalar and vector meson fields and their impact for NN forces. We parametrize the corresponding nonlinear field…
Strong interaction level shifts and widths in $\Sigma^-$ atoms are analyzed by using a $\Sigma$ nucleus optical potential constructed within the relativistic mean field approach. The analysis leads to potentials with a repulsive real part…
After discussion of mechanisms of lepton number violation, we consider meson decays $K^+ \to\pi^ - \ell ^ + \ell '^ +$ and $D^ + \to K^ - \ell ^ + \ell '^ +$ ($\ell,\ell ' = e,\mu $) with $\Delta L= 2$ in the Standard Model extended by…
The weak decays of hyperons and hypernuclei are studied from the chiral symmetry viewpoint. The soft pion relations are useful in understanding the isospin properties of the weak hyperon decays. Recent development on the short-range part of…
Low energy $\pi^+$ emission in hypernuclear weak decays is studied in the soft pion limit. It is found that the $\pi^+$ decay amplitude is dominated by the $\Delta I=3/2$ part of nonmesonic weak decays according to the soft pion theorem.…
Isospin effects on the optical potentials of kaons and antikaons in dense hadronic matter are investigated using a chiral SU(3) model. These effects are important for asymmetric heavy ion collision experiments. In the present work the…
We analyze the effects of $\delta-$ meson on hypernuclei within the frame-work of relativistic mean field theory. The $\delta-$ meson is included into the Lagrangian for hypernuclei. The extra nucleon-meson coupling ($g_\delta$) affects the…
In this work we extend our formalism to study meson-baryon interactions by including $s$- and $u$-channel diagrams for pseudoscalar-baryon systems. We study the coupled systems with strangeness $-1$ and focus on studying the isospin-1…
The theoretical status of the neutrino-nucleon cross section is reviewed for incident neutrino energies up to E_nu=10^12 GeV, including different approaches to high energy extrapolations. Nonstandard model physics may play a role at…
The contribution of mesonic exchange currents to nuclear Compton scattering is investigated within the framework of a Fermi gas model of nuclear matter in the non-relativistic limit. The additional interaction between the nucleons is…
It has been commonly assumed that pseudoscalar contributions to the leptonic decay of charged mesons, like pions and kaons, is strongly constrained due to the helicity suppression present in the ratio $R_{l/l'} = \Gamma(P \rightarrow…
A general algorithm for handling the energy dependence of hadron-nucleon amplitudes in the nuclear medium, consistently with their density dependence, has been recently applied to antikaons, eta mesons and pions interacting with nuclei.…
The formal properties of the recently derived set of linearly independent invariant amplitudes for the electromagnetic production of a pseudoscalar particle from a spin-one particle have been further exploited. The crossing properties are…
New physics (NP) in charmless strangeness-changing $B$ and $B_s$ decays, which are dominated by the $b \to s$ penguin amplitudes, can either preserve isospin or change it by one unit. A general formalism is presented studying pairs of…
The strong interaction effects of isospin- and spin-dependent nucleon-nucleon correlations observed in many-body calculations are interpreted in terms of a one-pion exchange mechanism. Including such effects in computations of nuclear…
Analyses of comprehensive sets of strong-interaction data consisting of level shifts, widths and yields in strange atoms of K mesons and Sigma hyperons are reviewed. The introduction of density dependent optical potentials, in both cases,…
An updated set of (anti)neutrino-nucleon charged and neutral current cross sections at $3~{\rm GeV} \lesssim E_\nu \lesssim 100~{\rm GeV}$ is presented. These cross sections are of particular interest for the detector optimization and data…