相关论文: Photo- and Electroproduction of the Hypertriton on…
Direct photon production is an important process at hadron colliders, being relevant both for precision measurement of the gluon density, and as background to Higgs and other new physics searches. Here we explore the implications of…
Total cross sections, angular distributions, and invariant-mass distributions have been measured for the photoproduction of $\pi^0\pi^0$ pairs off free protons and off nucleons bound in the deuteron. The experiments were performed at the…
We propose a simple meson-exchange model of the photoproduction of $\rho$- and $\omega$-mesons off protons near threshold ($E_\gamma$ less than 2 GeV). This model provides a good description of the available data and implies a large…
Elastic virtual photoproduction cross sections gamma^*p -> J/psi(psi')p and total charmonium-nucleon cross sections for J/psi, psi' and chi states are calculated in a parameter free way with the light-cone dipole formalism and the same…
In a series of experiments coherent and quasifree eta-photoproduction from light nuclei (4He, 3He, 2H) was investigated with the TAPS-detector at the Mainz MAMI-accelerator. The experiments were motivated by two different subjects: the…
{ {\bf Background:} Knowing the difference between the neutron and proton densities of nuclei is a significant topic because of its importance for understanding neutron star structures and cooling mechanisms. The coherent-nuclear…
Differential and total cross sections for the quasifree reactions $\gamma p\rightarrow\eta p$ and $\gamma n\rightarrow\eta n$ have been determined at the MAMI-C electron accelerator using a liquid deuterium target. Photons were produced via…
We study the $J/\psi$ photoproduction from nuclei near the kinematic threshold within the first collision model, based on the nuclear spectral function, for incoherent primary photon--nucleon charmonium creation processes. The model takes…
The $\eta$-meson photoproduction cross sections have been measured on the C and Cu targets for the photon energies between 600 and 1100 MeV to investigate the behavior of the $S_{11}$(1535) resonance in a nucleus. The excitation functions…
The emission of direct (hard and thermal) photons from nucleon-nucleon Bremsstrahlung in heavy-ion collisions at Fermi energies is analyzed. We utilize a photon emission rate based on a quantum-field-theoretical model together with nucleon…
Coherent photoproduction of \pi 0\eta\ on the deuteron, He3 and He4 nuclei is considered in the energy region from threshold to the lab photon energy 1.2 GeV. The transition amplitude is derived using impulse approximation. Effects of pion…
Background: Measurements of forward exclusive meson production at different squared four-momenta of the exchanged virtual photon, $Q^2$, and at different four-momentum transfer, t, can be used to probe QCD's transition from meson-nucleon…
We calculate the photon production cross section arising from the hard scattering of partons in nucleon-nucleon collisions by taking into account the intrinsic parton transverse momentum distribution and the next-to-leading-order…
We analyze the $\gamma N\to\pi N$ process in the negative parity channel with Hamiltonian effective filed theory which is successful in studying the nucleon resonances associated with the meson-nucleon scattering and lattice QCD…
The photoproduction reaction $\gamma N \to K K \Xi$ is investigated based on a relativistic meson-exchange model of hadronic interactions. The production amplitude is calculated in the tree-level approximation from relevant effective…
The amplitude for production of a single photon associated with quark pair in the fusion of two off-shell gluons is calculated. The matrix element found is applied to the inclusive prompt photon hadroproduction at high energies in the…
We investigate the photoproduction of K*0Sigma+ and K*+Sigma0 off the proton target, employing the effective Lagrangian approach at the tree-level Born approximation. In addition to the (s, t, u)-channel Born diagrams, we take into account…
We analyse in detail the role of additional hadron-hadron interactions in elastic photon-initiated (PI) production at the LHC, both in $pp$ and heavy ion collisions. We first demonstrate that the source of difference between our predictions…
In this work, we revise the conventional description of J/Psi(1S), Y(1S), Psi'(2S) and Y'(2S) elastic photo- and electroproduction off a nucleon target within the color dipole picture and carefully study various sources of theoretical…
The cross section of high-energy $e^+e^-$ pair production by a heavy charged particle in the atomic field is investigated in detail. We take into account the interaction with the atomic field of $e^+e^-$ pair and a heavy particle as well.…