Related papers: Are hyperon resonances required in the elementary …
A simple model for the photoproduction of kaons off protons with a lambda hyperon in the final state is presented. In a quark model, the interaction is modelled by the pair-creation of the (anti-) strange quarks in the final state which…
The $\phi$-$\Lambda(1520)$ interference effect in the $\gamma p\to K^+K^-p$ reaction has been measured for the first time in the energy range from 1.673 to 2.173 GeV. The relative phases between $\phi$ and $\Lambda(1520)$ production…
We consider the reactions gamma p --> M B, with M B being either K+ Lambda, K+ Sigma0, or Pi n, within a diquark model which is based on perturbative QCD. The model parameters and the quark-diquark distribution amplitudes of the baryons are…
We consider the $a_{1} (1260)$ contribution to photon and dilepton productions from hot hadronic matter. The effective lagrangian with $\pi, \rho$ and $a_{1}$ discussed by Ko and Rudaz is employed, which successfully reproduces the $\Gamma…
We compare the effects of several form factor recipes in fits to pseudoscalar meson photoproduction data. The specific examples of pion and kaon photoproduction are used to illustrate how different choices can alter the results of such…
Differential cross sections and hyperon polarizations have been measured for $\bar{K}^0 n$, $\pi^0 \Lambda$, and $\pi^0 \Sigma^0$ production in $K^- p$ interactions at eight $K^-$ momenta between 514 and 750 MeV/$c$. The experiment detected…
Previous approaches to the photo- and electro-production of strangeness off the proton, based upon effective hadronic Lagrangians, are extended here to incorporate the so called off-shell effects inherent to the fermions with spin >= 3/2. A…
Photoproduction of the $\Lambda^*(1520)$ resonance of spin-parity ${3\over2}^-$ off the proton target is investigated within the Regge framework where the $t$-channel reggeization is applied for the $K(494)+K^*(892)+K_2^*(1430)$ exchanges…
We have investigated phenomenological aspects of kaon photoproduction in three different extreme kinematics. The first kinematics of interest is the threshold region. At the threshold we have investigated the convergence of kaon…
Based on the fact that the mass difference between the chiral partners is an order parameter of chiral phase transition and that the chiral order parameter reduces substantially at the chemical freeze-out point in ultra-relativistic heavy…
We identify the leading s-wave amplitudes of the SU(3) chiral meson-baryon Lagrangian with an effective coupled-channel potential which is iterated in a Lippmann-Schwinger equation. The strangeness $S=-1$ resonance $\Lambda(1405)$ and the…
We calculate the processes $\gamma p \to K^0 \Sigma^+ , K^+ \Sigma^0, K^+ \Lambda$ in three flavor heavy baryon chiral perturbation theory to one loop. Some low--energy constants are fixed from single baryon properties while others are…
The photonic and QCD radiative corrections at next-to-leading order are calculated for fermion-pair production at muon colliders, maintaining the full mass dependence and helicity information of the muons and the produced fermions.…
The hyperon vector form factors at zero momentum transfer, $f_1(0)$, play an important role in a precise determination of the Cabibbo-Kobayashi-Maskawa matrix element $V_{us}$. Recent studies based on lattice chromodynamics (LQCD)…
We investigate the K* Lambda(1116) photoproduction off the proton target, employing the tree-level Born approximation within the effective Lagrangian approach. We take into account the kappa, K, and K* exchanges in the t channel in addition…
The photoproduction process of neutral kaons on a liquid deuterium target is investigated near the threshold region, Egamma = 0.8-1.1 GeV. K0 events are reconstructed from positive and negative pions, and differential cross sections are…
Results from a partial-wave analysis of the reaction $\gamma p \rightarrow K^+ \Lambda$ are presented. The reaction is dominated by the $S_{11}(1650)$ and $P_{13}(1720)$ resonances at low energies and by $P_{13}(1900)$ at higher energies.…
Background: Measurements of polarization observables for the reactions $\vec{\gamma} p \rightarrow K^+ \Lambda$ and $\vec{\gamma} p \rightarrow K^+ \Sigma^0$ have been performed. This is part of a programme of measurements designed to study…
We examine the importance of resonances for the non-leptonic hyperon decays in the framework of chiral perturbation theory. Lower lying resonances are included into the effective theory. Integrating out the heavy degrees of freedom in the…
We investigate the $\Lambda(1520)$ photoproduction in the $\vec{\gamma} p \to K^+ \Lambda(1520)$ reaction within the effective Lagrangian method near threshold. In addition to the "background" contributions from the contact, $t-$channel $K$…