论文标题
Au-au碰撞中的方位角敏感的三维HBT半径，$ e_ {beam} = 1.23 $$
Azimuthal-sensitive three-dimensional HBT radius in Au-Au collisions at $E_{beam} = 1.23$$A$ GeV by the IQMD model
论文作者
论文摘要
我们使用依赖依赖的量子分子动力学（IQMD）模型来模拟Beam Energy $ E_ {Beam} $ = 1.23 $ a $ GEV处的AU + AU碰撞，该$ = 1.23 $ a $ GEV，该中心对应于质量$ \ sqrt的中心{s_ {nn}}} = 2.4 $ gev。首先，与HADES数据相比，我们获得了$π^ - $和$π^+$的合理速度和横向质谱光谱，以及$π^+$的$π^+$。然后，通过计算相同带电对双对的三维汉伯里·布朗（Hanbury Brown）和Twiss（HBT）半径（HBT）半径，我们获得了向外半径和侧面半径的正方形差异，即$ r_ {out}^{2} {2} {2} -r_ {side}^{side}^{2}^{2} $，以及base and there there there there there there there（$ v_} $）实验结果。 HBT半径的方位角依赖性也通过矩阵方法计算，并通过旋转矩阵校正。 In addition, the eccentricities of the $xy$- and $zy$- planes of pion-pair emissions were also extracted for different pair transverse momentum and collision centrality, which show that the $xy$-eccentricity increases with pair transverse momentum as well as centrality but not for $zy$-eccentricity, indicating a more asymmetric transverse emission of particle-pairs with higher transverse momentum in off-central碰撞。
We used an Isospin dependent Quantum Molecular Dynamics (IQMD) model to simulate Au + Au collisions at beam energy $E_{beam}$ = 1.23$A$ GeV, which corresponds to center of mass energy $\sqrt{s_{NN}} = 2.4$ GeV. Firstly, we obtained reasonable rapidity and transverse mass spectra of $π^-$ and $π^+$ as well as "apparent" temperature parameters in comparison with the HADES data. Then by calculating three-dimensional Hanbury Brown and Twiss (HBT) radius of same charged pion-pairs, we obtained the square difference of outward radius and sideward radius, i.e. $R_{out}^{2}-R_{side}^{2}$, as well as the freeze-out volume ($V_{fo}$), which were basically consistent with the trend of HADES experimental results. The azimuthal dependence of the HBT radii was also calculated by a matrix method, and corrected by the rotation matrix. In addition, the eccentricities of the $xy$- and $zy$- planes of pion-pair emissions were also extracted for different pair transverse momentum and collision centrality, which show that the $xy$-eccentricity increases with pair transverse momentum as well as centrality but not for $zy$-eccentricity, indicating a more asymmetric transverse emission of particle-pairs with higher transverse momentum in off-central collisions.
