Related papers: Probing neutron-proton dynamics by pions
Electroproduction of neutral pions in exclusive reaction $p(e,e'\pi^0)p$ is studied above the resonance region, $\sqrt{s}>2$ GeV. The reaction amplitude is described by exchanges of vector $\omega(782)$, $\rho(770)$ and axial-vector…
We study the reaction of pion photoproduction on the nucleon in the framework of chiral perturbation theory with explicit $\Delta(1232)$ degrees of freedom. In the covariant approach, we give results up to order $\epsilon^3$ in the small…
Data on J/psi production in inelastic proton-proton, proton-nucleus and nucleus-nucleus interactions at 158 A GeV are analyzed and it is shown that the ratio of mean multiplicities of J/psi mesons and pions is the same for all these…
Charged pion production via charged current $\nu_{\mu}$ interactions on plastic (CH) is studied using the MINERvA detector exposed to the NuMI wideband neutrino beam at Fermilab. Events with hadronic invariant mass W $<$ 1.4 GeV are…
In a one-pion plus one-kaon exchange model, we calculate the kaon production cross sections in nucleon-nucleon, nucleon-delta and delta-delta interactions. We find that this model describes reasonably well the experimental data on kaon…
Incorporating a newly improved isospin- and momentum-dependent interaction in the isospin-dependent Boltzmann-Uehling-Uhlenbeck transport model IBUU11, we have investigated relative effects of the density dependence of nuclear symmetry…
Revealing the neutron density distribution in the nucleus is one of the crucial tasks of nuclear physics. Within the framework of the ultrarelativistic quantum molecular dynamic model followed by a correlation afterburner program, we…
In the framework of the isospin-dependent Boltzmann-Uehling-Uhlenbeck transport model, sensitive regions of some nucleon observables to the nuclear symmetry energy are studied. It is found that the symmetry energy sensitive observable n/p…
In this report, we will briefly review the dynamical model of pion electroweak production reactions in the $\Delta$ resonance region and report on our study of neutrino-nucleus reactions based on this model.
We present a relativistic calculation of pion scattering, pion photoproduction and Compton scattering on the nucleon in the energy region of the \Del-resonance (upto 450 MeV photon lab energy), in a unified framework which obeys the…
Triple differential cross sections of pions in heavy ion collisions at 1 GeV/nucl. are studied with the IQMD model. After discussing general properties of $\Delta$ resonance and pion production we focus on azimuthal correlations: At…
In this contribution I discuss the nuclear symmetry energy in the regime of hadronic degrees of freedom. The density dependence of the symmetry energy is important from very low densities in supernova explosions, to the structure of…
The properties of the high energy pions observed in heavy ion collisions, in particular in the system Au on Au at 1 GeV/nucleon are investigated. The reaction dynamics is described within the Quantum Molecular Dynamics (QMD) approach. It is…
Central collisions induced by high energy radioactive beams can be used as a novel means to obtain crucial information about the high density ({\rm HD}) behaviour of nuclear symmetry energy. This information is critical for understanding…
We present theoretical results for (gamma,pi0 pi0) and (gamma,pi+- pi0) production on nucleons and nuclei in the kinematical region where the scalar isoscalar pi pi amplitude is influenced by the sigma pole. The final state interaction of…
The quantum molecular dynamics model has been improved to investigate the reaction dynamics induced by antiprotons. The reaction channels of elastic scattering, annihilation, charge exchange and inelastic collisions have been included in…
Within the framework of an isospin and momentum dependent transport model, the emissions of isospin particles (nucleons and light clusters) squeezed out in heavy-ion collisions are investigated as probes of the poorly known symmetry energy…
The ratio of pre-equilibrium neutrons to protons from collisions of neutron-rich nuclei is studied as a function of their kinetic energies. This ratio is found to be sensitive to the density dependence of the nuclear symmetry energy, but is…
Within the framework of Lanzhou quantum molecular dynamics transport model, the correlation of initial deformation and isospin diffusion is systematically investigated in collisions of $^{238}$U + $^{238}$U. The impacts of the collision…
Pion energy spectra are presented for central collisions of neutron-rich 132Sn+124Sn and neutron-deficient 108Sn+112Sn systems using simulations with Boltzmann-Uehling-Uhlenbeck transport model. These calculations, which incorporate…