Direct photon emission and influence of dynamical wave packets in an extended quantum molecular dynamics model

Abstract

Direct photon produced from first proton-neutron ($p$-$n$) collision during the early stage of heavy ion reaction is a sensitive probe to reflect energy and momentum distribution of nucleons. In this work, we embedded the hard photon production channel in an extended quantum molecular dynamics (EQMD) model, and took the direct photon as a possible probe to improve namely the Fermi motion in the EQMD model. A possible scheme is offered to handle the dynamical wave packet width within incoherent bremsstrahlung process. Direct photons calculated by our modified EQMD were compared with data of ${}^{14}$N + ${}^{12}$C at beam energies $E/A$ = 20, 30 and 40 MeV, and it is found that the yield, inverse slope and angular distribution of direct photons could be reasonably reproduced. In addition, asymmetric reaction systems of ${}^4$He + C and ${}^4$He + Zn at $E/A$ = 53 MeV are also simulated in this work. It is found that the symmetric angular distribution in the nucleon-nucleon ($N$-$N$) center-of-mass (c.m.) frame and the velocity of $the\gamma$-emission source can be reasonably obtained from our method although there is some quantitative differences.

9 pages, 8 figures

References in corpus (9)

• Giant Dipole Resonance as a Fingerprint of $\alpha$ Clustering Configurations in ${}^{12}$C and ${}^{16}$O
• Symmetry Energy of Nucleonic Matter With Tensor Correlations
• The interplay of short-range correlations and nuclear symmetry energy in hard photon productions from heavy-ion reactions at Fermi energies
• Hard photon flow and photon-photon correlation in intermediate energy heavy-ion collisions
• Investigation of giant dipole resonance in heavy deformed nuclei with the EQMD model
• Azimuthal asymmetry of direct photons in intermediate energy heavy-ion collisions
• Iso-vector dipole resonance and shear viscosity in low energy heavy-ion collision
• Parametrization of the nucleus-nucleus gamma-ray production cross sections below 100 GeV/nucleon: Subthreshold pions and Hard photons
• Giant dipole resonance in proton capture reactions using an extended quantum molecular dynamics model

Cited by in corpus (7)

• $\alpha$-clustering effect on flows of direct photons in heavy-ion collisions
• Imprints of high-momentum nucleons in nuclei on hard photons from heavy-ion collisions around the Fermi Energy
• Short range correlations in the extended quantum molecular dynamics model
• Effect of initial-state geometric configurations on the nuclear liquid-gas phase transition
• Effects of neutron-skin thickness on direct hard photon emission from reactions induced by the neutron-rich projectile ${}^{50}$Ca
• Isovector giant dipole resonance mode with an improved propagation approach in the framework of EQMD model
• Influence of Cluster Configurations and Nucleon--Nucleon Scattering Cross-Section on Stopping Power in Heavy-Ion Collisions