共查询到14条相似文献,搜索用时 46 毫秒
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高能重离子碰撞中末态粒子的关联度与集合侧向流 总被引:1,自引:0,他引:1
提出了关联度概念,采用粒子群关联函数方法对Bevalac流光室1.2A GeV Ar+BaI2碰撞事件中关联度不同的粒子对集合侧向流的作用进行了研究.研究表明:关联度是描述集合侧向流性质的一个重要参量.少数关联度较大的粒子(或碎片)可以产生集合侧向流效应,但高阶集合流关联却不受其支配,而是关联度不同的多数粒子(或碎片)集体贡献的结果. 相似文献
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相对论重离子碰撞中集合流的横向运动关联 总被引:2,自引:0,他引:2
本文对1.2AGeV Ar+BaI2和2.1 AGeV Ne+NaF碰撞的Bevalac流光室4π实验数据进行了集合流横向运动关联特性的研究.研究表明,末态粒子的横向运动不仅存在粒子分布的方位角关联,而且还存在横向动量模的关联;Ar+BaI2碰撞实验中粒子分布的方位角关联、横向动量模关联和横向运动关联都分别强于Ne+NaF碰撞实验中相对应的各种关联;对于这两组碰撞实验,粒子分布的方位角关联相对横向动量模关联在横向运动关联中起着主要作用. 相似文献
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在BUU方程中引入真实的与动量和密度相关的平均场及介质中与密度和能量相关的核子-核子碰撞截面.在各种入射能量和碰撞参数下,对于反应Ca40+Ca40求解BUU方程.系统地计算和分析了集体流随时间变化的过程,结果表明:动量相关势和介质效应对集体流都有明显的影响,而且这种影响都有明显的能量和碰撞参数相关性. 相似文献
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用量子分子动力学(QMD)模型研究了中能重离子碰撞中的K+介子流. 计算结果显出, 实验数据只能与计入由手征拉格朗日导出的K+平均场势的结果相符合.这表明, K+介子边流的形式是对在核介质中K+位势的一个有效的探针. 相似文献
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S.Manly B.Alver B.B.Back M.D.Baker M.Ballintijn D.S.Barton R.R.Betts R.Bindel W.Busza Z.Chai V.Chetluru E.Garcia T.Gburek 《中国物理 C》2007,31(12):1133-1136
Recent measurements of event-by-event elliptic flow in Au+Au collisions at sNN=200GeV exhibit large relative fluctuations of about 40%—50%. The data are well described by fluctuations in the shape of the initial collision region, as estimated event-by-event with the participant eccentricity using Glauber Monte Carlo. These results, combined with the demonstrated participant eccentricity scaling of the elliptic flow across nuclear species, constitute evidence of transverse granularity in the initial matter production in these collisions. 相似文献
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Recent measurements of event-by-event elliptic flow in Au Au collisions at S_(NN)~(1/2)=200GeV exhibit large relative fluctuations of about 40%—50%.The data are well described by fluctuations in the shape of the initial collision region,as estimated event-by-event with the participant eccentricity using Glauber Monte Carlo.These results,combined with the demonstrated participant eccentricity scaling of the elliptic flow across nuclear species,constitute evidence of transverse granularity in the initial matter production in these collisions. 相似文献
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从35 MeV/nucleon 40Ca+40Ca反应实验数据中提取了碎片Z从1到9的横向流,发现探测器阈值、探测系统的角分辨等实验条件对横向流电荷依赖的形状有显著的影响。在考虑实验条件并采用软的核物质状态方程(K=200 MeV)之后,CoMD模型计算结果很好地重现了实验中横向流电荷依赖的形状。这表明如果要更加精确地提取实验中的横向流,必须使用阈值更低、角分辨更好的探测系统。此外,结合Kohley等[Phys Rev C,2012,85:064605]从实验中提取的横向流,讨论了横向流电荷依赖的形状存在异同的原因。1 ≤ Z ≤ 6的横向流电荷依赖呈肩峰形状可能是实验条的影响引起的,而我们的实验中Z ≥ 6的横向流的减小可能是由于动量守恒对集体运动的抑制。The transverse flow in the reaction of 40Ca+40Ca at 35 MeV/nucleon has been determined for emitted isotopes with Z=1 to 9. A significant modification of the Z-dependent flow pattern caused by the experimental filters, the detector thresholds and the angular resolutions (△?) of the detector array, is observed. With the application of the appropriate experimental filters, the general trend of the experimental Z-dependent flow is well reproduced by the Constrained Molecular Dynamics (CoMD) simulation, employing an effective interaction corresponding to a soft EOS (K=200 MeV). This fact suggests that to determine the flow values more precisely, a detection system with lower energy threshold and better angular resolution is urgently required. Additionally, together with the parallel work of Z. Kohley et al.[Phys Rev C, 2012, 85:064605], the pattern of the experimental Z dependence of transverse flow is also discussed. The shoulder patterns of Z-dependent flow for 1 ≤ Z ≤ 6 can be attributed by the experimental filters, while the reduction of flow for Z ≥ 6 in our experiment can be caused by the suppression of collective motion under the momentum conservation. 相似文献