论文标题
具有MEDIUM $ρ$ -MESON光谱功能的微观运输理论中的Dilepton生产
Dilepton production in microscopic transport theory with in-medium $ρ$-meson spectral function
论文作者
论文摘要
我们使用微观GIBUU传输模型来计算SIS18 Energies重型离子碰撞中的DiLepton（$ E^+E^ - $）的生产，重点是$ρ$ -Meson的碰撞扩展的影响。根据Gibuu模型的碰撞积分，计算出核物质中$ρ$ - 米森在有限温度下的碰撞宽度。进行了与HADES有关重型离子碰撞中DILEPTON生产的数据的系统比较。 $ρ$的碰撞扩展改善了$ρ$极质量质量的Dilepton不变性质量分布的理论和实验之间的协议，以及Au+au的过剩辐射（$ 1.23）$ GEV。我们此外表明，C+C中的一些实验性DILEPTON SPESTRA的预测不足，$ 1 a $ gev和au+au $ gev和$ 1.23 $ gev a $ gev a $ gev在中间不变的群众$ 0.2-0.4 $ $ gev可以通过与$ pn $ bremsstrahung crosse $ pn $ bremsstrahung croppect $ pn $ bremsstrahung croppect $ pn $ bremsstrahung cropped propperr $ 0.2-0.4 $ gev一起考虑。 $ GEV。
We use the microscopic GiBUU transport model to calculate dilepton ($e^+e^-$) production in heavy-ion collisions at SIS18 energies focusing on the effect of collisional broadening of the $ρ$-meson. The collisional width of the $ρ$-meson at finite temperature and baryon density in nuclear matter is calculated on the basis of the collision integral of the GiBUU model. A systematic comparison with HADES data on dilepton production in heavy-ion collisions is performed. The collisional broadening of the $ρ$ improves the agreement between theory and experiment for the dilepton invariant-mass distributions near the $ρ$ pole mass and for the excess radiation in Au+Au at $1.23 A$ GeV. We furthermore show that some remaining underprediction of the experimental dilepton spectra in C+C at $1 A$ GeV and Au+Au at $1.23 A$ GeV at intermediate invariant masses $0.2-0.4$ GeV can be accounted for by adjusting the $pn$ bremsstrahlung cross section in a way to agree with the inclusive dilepton spectrum from $dp$ collisions at $1.25 A$ GeV.
