共查询到17条相似文献,搜索用时 78 毫秒
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应用ART模型研究了Eb=520MeV/u的UU碰撞. 探讨了在两种极端方位UU碰撞下, 核子和π在反应平面内的横向流的时间演化以及对碰撞中心度的依赖关系. 研究表明, 流在高密区域发展并且在膨胀相稳定, 因而它是高密区域反应动力学的一个敏感探针. 对头头和体体UU碰撞, 末态π相对于核子的横向流分别在大约b=9fm和b=2fm处存在明显的正向到负向的改变. π的这种行为是重子共振态和旁观者的遮蔽效应(再散射和再吸收)共同作用的结果. 相似文献
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在夸克味动力学的计算中,除包含u、d、s夸克及其反夸克外,还涉及粲夸克及其反夸克(cc),采用包含夸克味动力学效应的相对论性流体力学模型,计算了碰撞能量为200GeV/u的238U+238U核碰撞时形成的膨胀QGP及其在相变过程中发射的双轻子谱,轻子对的质量范围M≤4GeV/c2.计算结果与CERNSPS的实验测量数据进行了定性的比较和分析,得到初步的结论:由于夸克碎块和味动力学效应,J/ψ→μ++μ-峰值被降低,导致低质量区(阈至1.35GeV/c2)谱的提高. 相似文献
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57MeV/u 64Zn+27Al反应中集体流的研究 总被引:1,自引:0,他引:1
贺智勇 J.Peter J.C.Angelique G.Bizard R.Brou D.Cussol A.Kerambrun J.P.Patry R.Regimbart J.C.Steckmeyerr B.Tamain E.Vient G.Auger C.Cabot 《中国物理 C》1994,18(9):800-806
报道了利用4π带电粒子阵列测量的57MeV/u的64Zn轰击27Al反应中的集体物质流.各事件的碰撞参数分类采用平均平行速度方法,反应平面的确定采用横向动量分析方法.实验观察到在反应平面内的集体横向动量(边流参数)随着碰撞参数和粒子产物而变化. 相似文献
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用相对论平均场理论和非相对论平均场理论计算了双幻核100Sn的结合能,核物质分布半径,中子分布半径和质子分布半径等,并对这两种理论计算结果进行了比较和讨论.这是对100Sn核的第一个微观计算. 相似文献
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S.J.Sanders 《中国物理 C》2007,31(12):1137-1140
Identified particle elliptic flow results are presented for the Au+Au reaction at sNN=200GeV as a function of transverse momentum and pseudorapidity. Data at pseudorapidities η≈0,1, and 3.4 were obtained using the two BRAHMS spectrometers. Differential v2 (η,pt) values for a given particle type are
found to be essentially constant over the covered pseudorapidity range, in contrast to the integral v2 values which have previously been observed to decrease at forward rapidities. A softening of the particle spectra at forward angles is found to account for at least part of the integral v2 falloff. The data are found to be consistent with existing constituent quark scaling systematics. 相似文献
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Kentaro Miki 《中国物理 C》2007,31(12)
Azimuthal anisotropy of direct photon is measured in (√SNN)=200GeV Au Au collisions at RHICPHENIX. Direct photon is one of the most effective probes to study properties of hot dence medium at initial state (also QGP state) of heavy ion collisions because photons almost do not interact strongly with any other particles caused by its long mean free path and they keep their conditions when they are created. Within statistical and systematic errors, the elliptic flow parameter (v2) of direct photon is consistent with zero.Direct photon v2 is estimated by hadron decay photon contamination are subtracted from inclusive photon v2 in intermediate to high transverse momentum (pT) region (0 to 10GeV/c) for 3 centrality selections (20% steps) and minimum bias. 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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A new method is presented for measuring event-by-event fluctuations
of elliptic flow (v2) using first-order event planes.
By studying the event-by-event distributions of v2 observables and first-order event-plane observables, average flow
〈v2〉and event-by-event fluctuations with respect to that
average can be separately determined, making appropriate allowance
for the effects of finite multiplicity. The relation of flow fluctuations to eccentricity fluctuations in the initial-state participant region, as well as detector acceptance effects, are discussed. 相似文献
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Kentaro Miki 《中国物理 C》2007,(12)
Azimuthal anisotropy of direct photon is measured in S_(NN)~(1/2)=200GeV Au Au collisions at RHIC- PHENIX.Direct photon is one of the most effective probes to study properties of hot dence medium at initial state(also QGP state)of heavy ion collisions because photons almost do not interact strongly with any other particles caused by its long mean free path and they keep their conditions when they axe created.Within statistical and systematic errors,the elliptic flow parameter(v_2)of direct photon is consistent with zero. Direct photon v_2 is estimated by hadron decay photon contamination are subtracted from inclusive photon v_2 in intermediate to high transverse momentum(p_T)region(0 to 10GeV/c)for 3 centrality selections(20% steps)and minimum bias. 相似文献