在CERN超级质子同步加速器上测量的20 A,30 A,40 A,80 A和158 A GeV Pb+Pb碰撞中λ和Xi产生的能量依赖性
Energy dependence of Lambda and Xi production in central Pb+Pb collisions at 20A, 30A, 40A, 80A, and 158A GeV measured at the CERN Super Proton Synchrotron
NA49 Collaboration
备注:
16 pages, 16 figures. Finally published version after editorial revision
给出了20 A、30 A、40 A、80 A和158 A GeV中心Pb+Pb反应中$Λ$、$\barΛ}$、$Ξ^{-}$和$\barΞ^{+}$的产生结果。讨论了横质量谱、快度谱和多重性的能量依赖性。弦强子模型(UrQMD和HSD)和统计强子气体模型的比较。虽然后者提供了一个合理的描述,所有的粒子产量,第一类模型未能匹配的$Ξ^{-}$,和$\barΞ^{+}$多重性。
英文摘要:
Results on $Λ$, $\barΛ}$, $Ξ^{-}$, and $\barΞ^{+}$ production in central Pb+Pb reactions at 20A, 30A, 40A, 80A, and 158A GeV are presented. The energy dependence of transverse mass spectra, rapidity spectra, and multiplicities is discussed. Comparisons to string hadronic models (UrQMD and HSD) and statistical hadron gas models are shown. While the latter provide a reasonable description of all particle yields, the first class of models fails to match the $Ξ^{-}$, and $\barΞ^{+}$ multiplicities.
System-size dependence of Lambda and Xi production in nucleus--nucleus collisions at 40A and 158A GeV measured at the CERN Super Proton Synchrotron
给出了40 A和158 A GeV中心选择Pb+Pb反应和158 A GeV近中心C+C和Si+Si反应中λ、反λ和Xi-产生的结果。横向质谱,快度谱,和依赖于系统大小的多重性进行了讨论。运输模型(UrQMD2.3和HSD)和核心电晕的方法进行比较。虽然λ和反λ的产生可以通过传输模型合理地描述,但这些模型与Xi-测量不一致。另一方面,核心电晕图片非常适合的系统尺寸依赖的λ和Xi-,而它同意不太好与反λ数据。
Lambda production in central Pb+Pb collisions at CERN-SPS energies
本文介绍了在40、80和158 A $\cdot$ GeV的中心Pb+Pb碰撞中产生的$Λ$和$\barΛ$超子的NA 49实验的最新结果。横向质谱和快度分布的$Λ$显示为所有三种能量。随着束流能量的增加,快度分布的形状变得更平坦。在中快度的多重性以及总产量作为碰撞能量的函数,包括AGS测量研究。中快度和4 $π$中的$Λ/π$比在40 A $\cdot$ GeV左右有一个最大值。此外,$\barΛ$快度分布已被测量在40和80 A $\cdot$ GeV,这允许研究的$\barΛ$ / $Λ$的比例。
Search for critical behavior of strongly interacting matter at the CERN Super Proton Synchrotron
综述了在欧洲核子研究中心(CERN)超质子同步加速器上研究核-核碰撞产生的强相互作用物质临界行为的历史、现状和计划。特别是,预计搜索应该回答的问题是否存在强相互作用物质的临界点,如果存在,它位于何处。首先,提出了搜索策略,并给出了一个简短的介绍,预期的波动信号和实验所使用的量,以检测最重要的背景效应也进行了讨论。其次,对相关实验结果进行了总结和讨论。有趣的是,在158 A GeV/c的中等大小的Si+Si碰撞中,在整个实验接受范围内积分的量的波动(事件多重性和横向动量)以及π介子和质子多重性的第二阶乘矩的仓大小依赖性都表明了所产生的物质的临界行为。这些结果提供了强有力的动力,正在进行的系统扫描的相图的NA 61/SHINE实验在SPS和继续搜索在布鲁克海文相对论强子对撞机。
Measurement of event-by-event transverse momentum and multiplicity fluctuations using strongly intensive measures $Δ[P_T, N]$ and $Σ[P_T, N]$ in nucleus-nucleus collisions at the CERN Super Proton Synchrotron
Elliptic flow of Lambda hyperons in Pb+Pb collisions at 158A GeV
在CERN-SPS的NA 49合作组中,测量了158 AGeV半中心Pb+Pb碰撞中λ超子的椭圆流.使用将粒子与事件平面相关联的标准方法。测量V2近中快度的报告作为一个功能的快速性,中心性和横向动量。Lambda粒子的椭圆流随着碰撞参量和横向动量的增加而增加。它是比较与V2的π介子和质子,以及与模型计算。显著的椭圆流和它的质量依赖性的观察表明强烈的集体行为的重核碰撞已经在SPS产生的物质。在158 A GeV能量下,对不同粒子种类的椭圆流的标度特性进行了测试。数据的pT范围有限,无法对聚结模型进行决定性检验。
NA61/SHINE is an experiment at the CERN Super Proton Synchrotron. The main goals of the experiment are the search for the critical point of strongly interacting matter and the study of the properties of the onset of deconfinement. To reach these goals, the two-dimensional scan in beam momentum ($13A-150A$ GeV/$c$) and system size ($p$+$p$, Be+Be, Ar+Sc, Xe+La, Pb+Pb) was performed. In the final stage of the collision, the spectra of protons are only weakly affected by the effects of resonance decays and rescattering due to their large mass. Thus, proton rapidity distribution is particularly se…
NA61/SHINE is a multipurpose fixed-target facility at the CERN Super Proton Synchrotron. The main goals of the NA61/SHINE strong interactions program are to discover the critical point of strongly interacting matter and study the properties of the onset of deconfinement. To reach these goals, hadron production measurements are performed in the form of a two-dimensional scan by varying collision energy and system size. The Collaboration has recently finished data acquisition for its original program on strong interactions, accumulating broad data samples on hadron production in various systems …
A measurement of charged hadron pair correlations in two-dimensional $ΔηΔϕ$ space is presented. The analysis is based on total 30 million central Be+Be collisions observed in the NA61/SHINE detector at the CERN SPS for incident beam momenta of 19$A$, 30$A$, 40$A$, 75$A$, and 150$A$ GeV/$c$. Measurements were carried out for unlike-sign and like-sign charge hadron pairs independently. The $C(Δη,Δϕ)$ correlation functions were compared with results from a similar analysis on p+p interactions at similar beam momenta per nucleon. General trends of the back-to-back correlations are similar in centr…
Measurements of multiplicity fluctuations of identified hadrons produced in inelastic p+p interactions at 31, 40, 80, and 158~\GeVc beam momentum are presented. Three different measures of multiplicity fluctuations are used: the scaled variance $ω$ and strongly intensive measures $Σ$ and $Δ$. These fluctuation measures involve second and first moments of joint multiplicity distributions. Data analysis is performed using the Identity method which corrects for incomplete particle identification. Strongly intensive quantities are calculated in order to allow for a direct comparison to correspondi…
Measurements of Hadron Production in Pion-Carbon Interactions with NA61/SHINE at the CERN SPS
NA 61/SHINE是在CERN超级质子同步加速器上设计的一个固定靶实验,用于研究强子-质子、强子-核和核-核相互作用。在这一过程中,我们提出了在π介子-碳生产相互作用,这是根本的重要性,以改善广泛的空气簇射建模,从而解释超高能宇宙射线测量确定强子的光谱结果。特别是,我们的测量(反)重子和$ρ^0$生产的π-碳相互作用可以有助于改善预测的μ子生产的空气簇射模拟使用强子相互作用模型。在这篇文章中,我们讨论了数据分析和结果从介子-碳碰撞记录在束流动量为158和350 GeV/c。初步频谱的$K^{\pm}$和$p$($\bar{p}$),以及比较预测的强子相互作用模型中使用的空气簇射模拟。此外,我们目前的最终结果的生产$ρ^0$,$ω$和$K^{0*}$共振。
Recent results in relativistic heavy ion collisions: from ``a new state of matter'' to "the perfect fluid"
相对论重离子实验物理学始于1992年,当时布鲁克海文国家实验室(BNL)的交替梯度同步加速器(AGS)首次获得了能量大于10 A GeV/c的197 Au束,随后在1994年欧洲核子研究中心(CERN)的超级质子同步加速器(SPS)获得了158 A GeV/c的208 Pb束。在20世纪70年代末和80年代初,伯克利Bevalac实验室进行的开创性测量是在低得多的轰击能量(~ 1 A GeV/c)下进行的,其中核分裂而不是粒子产生是A+A碰撞中占主导地位的非弹性过程。最近,从2000年开始,BNL的相对论重离子对撞机(RHIC)产生了两个100 A GeV完全剥离的Au离子束的正面碰撞,对应于核子-核子质心能量,sqrt(sNN)=200 GeV,总c.m.。能量200 A GeV。这项研究计划的目标是产生具有极端密度和温度的核物质,可能导致一种物质状态,在这种状态下,通常被限制在单个核子(r < 1 fm)内的夸克和胶子可以在更大的距离上自由活动。将审查从1992年至今的进展情况,并酌情参考以前轻离子和质子-质子碰撞的结果。重点将放在两个主要实验室宣布的测量基础上:CERN于2000年2月10日宣布的“一种新的物质状态”和BNL于2005年4月19日宣布的“完美流体”。
Measurements of $π^\pm$, K$^\pm$, p and $\bar{\textrm{p}}$ spectra in proton-proton interactions at 20, 31, 40, 80 and 158 GeV/c with the NA61/SHINE spectrometer at the CERN SPS
Recent results and future of the NA61/SHINE strong interactions program
NA 61/SHINE是欧洲核子研究中心超级质子同步加速器上的一个固定目标实验。该实验的主要目的是发现强相互作用物质的临界点,并研究解谐开始的性质。为了达到这些目标,合作研究强子生产性质的核-核,质子-质子和质子-核相互作用。在这次演讲中,最近的结果在p+p相互作用,以及在SPS能量范围内的Be+Be和Ar+Sc碰撞的粒子生产进行了审查。结果与现有的世界数据进行了比较。最后对NA 61/SHINE科学计划的未来作了展望。
NA 61/SHINE是欧洲核子研究中心超级质子同步加速器上的一个固定目标实验。该实验的主要目标是发现强相互作用物质的临界点,并研究解除禁闭开始的性质。为了达到这些目标,强子产生的性质进行了研究,在核-核,质子-质子和质子-核相互作用作为碰撞能量和碰撞核的大小的函数。在这次演讲中,最近的结果在p+p相互作用,以及在SPS能量范围内的Be+Be和Ar+Sc碰撞的粒子生产进行了审查。给出了用各种分析方法得到的横动量、横质量和快度谱。令人惊讶的研究签名的发病解除限制进行了讨论。结果与现有的世界数据进行了比较。
The production of $K^{0}_{S}$ mesons in inelastic $\textit{p+p}$ collisions at beam momentum 158 GeV/c ($\sqrt{s_{NN}}=17.3$ GeV) was measured with the NA61/SHINE spectrometer at the CERN Super Proton Synchrotron. Double-differential distributions were obtained in transverse momentum and rapidity. The mean multiplicity of $K^{0}_{S}$ was determined to be $0.162 \pm 0.001 (stat.) \pm 0.011 (sys.)$. The results on $K^{0}_{S}$ production are compared with model predictions (EPOS 1.99, SMASH 2.0, PHSD and UrQMD 3.4 models) as well as with published world data.
NA61/SHINE is a fixed target experiment at the CERN Super Proton Synchrotron. The main goals of the experiment are to discover the critical point of strongly interacting matter and to study the properties of the onset of deconfinement. In order to reach these goals, a study of hadron production properties is performed in nucleus-nucleus, proton-proton and proton-nucleus interactions as a function of collision energy and size of the colliding nuclei. In this talk, the new results on identified charged kaon production in the intermediate size system (Ar+Sc and Be+Be) collisions at SPS beam momen…
NA 61/SHINE是欧洲核子研究中心超级质子同步加速器上的一个固定目标实验。该实验的主要目的是发现强相互作用物质的临界点,并研究解除禁闭开始的性质。为了达到这些目标,强子产生的性质进行了研究,在核-核,质子-质子和质子-核相互作用作为碰撞能量和碰撞核的大小的函数。本文综述了SPS能区p+p、Be+Be和Ar+Sc碰撞中奇异产生的最新研究结果。将显示用各种分析方法得到的K介子的运动谱和平均多重数。奇异性的产生及其对系统尺寸的依赖性在附近的相变的概述也将提出。