论文标题
在扩展量子分子动力学模型中，动态波包的直接光子发射和影响
Direct photon emission and influence of dynamical wave packets in an extended quantum molecular dynamics model
论文作者
论文摘要
在重离子反应的早期阶段，首先质子中子（$ p $ - $ n $）碰撞产生的直接光子是反映核子能量和动量分布的敏感探针。在这项工作中，我们将硬光子生产通道嵌入了扩展的量子分子动力学（EQMD）模型中，并将直接光子作为可能的探针，以改善EQMD模型中的费米运动。提供了一个可能的方案来处理不一致的Bremsstrahlung过程中的动态波数据包宽度。将由我们修改的EQMD计算的直接光子与$^{14} $ n + $^{12} $ c的数据进行比较，beam Energies $ e/a $ = 20、30和40 MEV，发现收益率，逆斜率和直接光子的角度分布可以合理地重现。此外，在这项工作中，还模拟了$^{4} $ he + c和$ e/a $ = 53 meV的$^{4} $ he + c和$^{4} $ he + zn的不对称反应系统。发现发现，尽管存在一些定量差异，但可以合理地从我们的方法中合理地获得核子核子（$ n $ - $ n $）质量（$ n $ - $ n $）的对称角度分布。
Direct photon produced from first proton-neutron ($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 γ$-emission source can be reasonably obtained from our method although there is some quantitative differences.
