Related papers: $K^+\Lambda$ photoproduction at forward angles and…
The electroproduction of $K^+ \Lambda$ (1405) was studied by analyzing the E1F data set collected in Hall B at Jefferson Lab. The analysis utilized the decay channel $\Sigma^+ \pi^-$ of the $\Lambda$ (1405) and $p \pi^0$ of the $\Sigma^+$.…
Inspired by the preliminary experimental data by the CLAS Collaboration, the $K^{\ast 0}\Lambda$ photoproduction off a neutron is studied within an effective Lagrangian approach. The contributions from the Born terms including $s$, $u$, and…
We report on the measurement of the $\gamma p \rightarrow J/\psi p$ cross section from $E_\gamma = 11.8$ GeV down to the threshold at $8.2$ GeV using a tagged photon beam with the GlueX experiment. We find the total cross section falls…
Measurements of transverse polarization of Lambda hyperons produced in high energy pp collisions may help to address several open issues about Lambda production and polarization mechanisms, such as the amount of SU(3) breaking, the…
The $\Sigma(1385)$ resonance, or $\Sigma^*$, is well-known as part of the standard baryon decuplet with spin $J=3/2$. Measurements of the reaction $\gamma p \to K^+ \Sigma^{*0}$ are difficult to extract due to overlap with the nearby…
We analyze the recent total cross section data for $pp \to p\Lambda K^+$ near threshold measured at COSY. Using an effective range approximation for the on-shell $p\Lambda$ S-wave final state interaction we extract from these data the…
Cross-section measurements of the associated production of a top quark pair and a photon ($t\bar{t}\gamma$) are performed with an integrated luminosity of 140 fb$^{-1}$ of proton-proton collisions at a centre-of-mass energy of 13 TeV…
A gauge-invariant model is constructed for the $\gamma p \to K^+\Lambda(1690)$ reaction within a tree-level effective Lagrangian approach with the purpose to understand the underlying production mechanisms and to study the resonance…
The new experimental data of kaon photoproduction on the nucleon, gamma p -> K+ Lambda, have been analyzed by means of a multipoles model. Different from the previous models, in this analysis the resonance decay widths are constrained to…
We consider the cross section of electron-positron pair production by a high-energy photon in a strong Coulomb field close to the end of electron or positron spectrum. We show that the cross section essentially differs from the result…
The physics interpretation of the recent measurements of the spin polarization of $\Lambda$ hyperons produced in relativistic heavy-ion collisions is discussed. We suggest that the polarization measured in the $\Lambda$ rest frame should be…
Differential cross sections for eta photoproduction off protons have been measured at E_gamma = 1.6 - 2.4 GeV in the backward direction. A bump structure has been observed above 2.0 GeV in the total energy. No such bump is observed in cross…
Based on previous studies that support the important role of the $N^*(2120) D_{13}$ resonance in the $\gamma p \to K^+ \Lambda(1520)$ reaction, we make a re-analysis of this $\Lambda(1520)$ photoproduction reaction taking into account the…
The longitudinal or transverse spin transfer to Lambda and anti-Lambda hyperons in polarized proton-proton collisions is expected to be sensitive to the helicity or transversity distributions of strange and anti-strange quarks of the…
An experimental study of $\omega$ photoproduction on the proton was conducted by using the Crystal Ball and TAPS multiphoton spectrometers together with the photon tagging facility at the Mainz Microtron MAMI. The $\gamma p\to\omega p$…
We study the photo- and electro-productions of the vector kaon off the proton, i.e., $\gamma^{(*)}p\to K^{*+}\pi^0\Sigma^0$, and investigate the line shape of the $\pi^0\Sigma^0$ invariant mass in an effective Lagrangian approach with the…
The photoproduction reaction of $\gamma p \to K^+\Lambda(1405)$ is investigated based on an effective Lagrangian approach at the tree-level approximation with the purpose of understanding the reaction mechanism and extracting the resonance…
The process e+e- -> gamma gamma (gamma) is studied using data collected by the OPAL detector at LEP between the years 1997 and 2000. The data set corresponds to an integrated luminosity of 672.3pb-1 at centre-of-mass energies lying between…
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 $K$…
The production of photons at very small angles with respect to the proton beam direction is studied in deep-inelastic positron-proton scattering at HERA. The data are taken with the H1 detector in the years 2006 and 2007 and correspond to…