Related papers: Exchange currents in radiative hyperon decays and …
Electromagnetic interactions are introduced in the effective chiral Lagrangian for heavy mesons which includes light vector particles. A suitable notion of vector meson dominance is formulated. The constraints on the heavy meson -light…
Relativistic effects and the role of heavy meson exchange in deuteron photodisintegration are studied systematically for photon energies below the pion production threshold. In a (p/M)-expansion, all leading order relativistic one-body and…
The spectrum of the C=1 hyperons is well described by the constituent quark model, if the fine structure interaction between the light and strange quarks is mediated by the $SU(3)_F$ octet of light pseudoscalar mesons, which are the…
The charge radii and the decay rates of the pion and kaons are calculated, using the relativistic equation of motion with a linear potential. Those physical quantities are quite well explained with the current quark masses in the case of…
We study the Delta I =3/2 and Delta S =2 amplitudes for hyperon decays of the form (B to B(prime) pion) at lowest order in chiral perturbation theory. At this order, the Delta I=3/2 amplitudes depend on only one constant. We extract the…
The radiative meson decays $V\to P\gamma$ and $P\to \gamma\gamma$ are analyzed using the quark triangle diagram. Experimental data yield well determined estimates of the universal quark-antiquark-meson couplings $g_{Vq\bar{q}'}$ and…
Microscopical approach to a deuteron breakup at high and intermediate energies is proposed. We show that the quark exchange effects, resulting from the full asymmetry of the $6q$-deuteron wave function with respect to the pair permutations…
A secluded U(1) sector with weak admixture to photons, O(10^{-2}-10^{-3}), and the scale of the breaking below 1 GeV represents a natural yet poorly constrained extension of the Standard Model. We analyze g-2 of muons and electrons together…
Beta-decay and muon-capture experiments in nuclei are reviewed. The conserved vector current hypothesis is confirmed through the observed constancy of the vector coupling constant determined from the superallowed Fermi transitions and from…
Heavy hadron chiral perturbation theory (HHchiPT) and XEFT are applied to the decays X(3872) -> psi(2S) + gamma and psi(4040) -> X(3872) + gamma under the assumption that the X(3872) is a molecular bound state of neutral charm mesons. In…
The long-distance electromagnetic radiative corrections to tau- -> pi- pi0 nu are re-evaluated. A meson dominance model is used to describe the emission of real photons in this decay. Results obtained for the hadronic spectrum and the decay…
In order to characterize nuclear matter under extreme conditions, we calculate all diffusion transport coefficients related to baryon, electric and strangeness charge for both a hadron resonance gas and a simplified kinetic model of the…
We investigate the semileptonic hyperon decays within the framework of the self-consistent SU(3) chiral quark-soliton model ($\chi$QSM). We take linear $1/N_c$ rotational as well as linear $m_s$ corrections into account and apply the…
Recent reports of the observation of the decay $\tau \rarrow \nu_{\tau} + K + \pi + \pi$ raise interesting questions. The $u-s$ quark mass difference can induce an effective second-class current in the strange sector and enhance decays to…
The discrepancies found between S-wave and P-wave fits for hyperon decays are reinvestigated using the heavy baryon chiral Lagrangian formalism. The agreement is found to improve through the inclusion of previously omitted diagrams. The…
Cryptons are metastable bound states of fractionally-charged particles that arise generically in the hidden sectors of models derived from heterotic string. We study their properties and decay modes in a specific flipped SU(5) model with…
The nonmesonic weak decay of $\Lambda$ hypernuclei is studied in a shell model framework. A complete strangeness-changing weak $\Lambda N \to NN$ transition potential, based on one boson exchange, is constructed by including the exchange of…
We study two-photon contribution to the elastic lepton-proton scattering, associated with sigma meson exchange, with special attention paid to the low-Q2 region. We show that the corresponding amplitude grows sharply but remains finite at…
The chiral version of the QMC model, in which the effect of gluon and pion exchanges is included self-consistently, is applied to the hyperons in a nuclear medium. The hyperfine interaction due to the gluon exchange plays an important role…
We evaluate radiative decays of $\rho$ and $\omega$ going to two neutral mesons, $\pi^{0} \pi^{0}$ and $\pi^{0} \eta$. We use the sequential vector decay mechanisms in addition to chiral loops and $\rho$-$\omega$ mixing. The chiral loops…