共查询到19条相似文献,搜索用时 187 毫秒
1.
用蒙特卡洛方法对630GeV/c质子–反质子碰撞中的无偏样本、喷注事件样本和喷注内样本中的动力学起伏进行了研究.结果表明,喷注事件样本和电子–正电子对撞的全事件样本相似,近似地有各向同性的动力学起伏,而喷注内样本则和电子–正电子对撞的喷注一样,有类似于强子–强子碰撞软过程的各向异性动力学起伏.这表明,强子–强子碰撞中喷注的产生和演化分别和电子–正电子碰撞中喷注的产生和演化有类似的动力学性质. 相似文献
2.
3.
4.
高能强子–强子碰撞中硬软过程的比较分析 总被引:1,自引:1,他引:0
根据QCD中“圆锥定义”来确定喷注,对高能强子-强子碰撞中的硬、软过程作细致的分析.用Pythia产生蒙特卡罗模拟样本,得到的喷注赝快度分布在中心区有平台,喷注内部的粒子密度和横能密度,随离喷注轴的距离指数地下降,比较发现对整个事件样本,单事件平均横动量或最大横动量与多重数是正关联的,而对喷注事件它们是负关联的.引入两个物理量来描述喷注事件的硬、软程度.发现它们与单事件平均横动量是正关联的,而与多重数是负关联的.表明用单事件平均横动量比用多重数能更好地描述喷注事件的硬软程度. 相似文献
5.
近二十年来,世界上众多高能物理实验发现了大量超出传统夸克模型的共振结构。为了理解这些性质奇特的共振结构,科学家们提出了很多方法和模型。其中,因为实验上发现的这些奇特态大多处在一对强子阈值附近,强子分子态的观点得到了很多关注。本文我们将以粲–反粲强子对为例来探究哪些系统可以形成分子态,进而给出粲–反粲强子分子态的能谱。我们考虑了所有由S波粲介子、粲重子以及窄的P波粲介子构成的粲–反粲强子对。我们假定它们之间的相互作用由介子交换主导,在最低阶近似下可简化为常数。通过求解常数相互作用的Bethe–Salpeter方程,我们可以找到振幅的极点进而确定该系统分子态的质量。最终我们发现,那些通过轻矢量介子交换在阈值附近产生吸引力的系统,会存在一个靠近阈值的极点。不同的系统,由于其相互作用强度不同,极点可能会处于能量复平面的第一黎曼面或者第二黎曼面,分别对应于束缚态或者虚态。我们总共发现了229个强子分子态。很多实验上发现的那些位于粲–反粲强子对阈值附近的共振结构可以很好地与我们的结果吻合。另外,我们需要强调所预言的一个ΛcˉΛc分子态,这个态可以很好地解释北京正负电子谱仪(BESIII)上测量的数... 相似文献
6.
7.
Qiang ZHAO 《原子核物理评论》2020,37(3):260-271
综述了量子色动力学奇特强子态研究中的一些热点问题,特别强调了有效理论研究强子分子态可以合理考虑阈效应和“三角奇异性”对近阈奇特强子态性质的重要影响,综合分析这些可能的机制可以帮助我们更好地理解强子谱。 相似文献
8.
9.
用Chou-Yang模型构造了一个用于s=26GeV到22TeV的软强子非单衍相互作用MonteCarlo产生器.结合大横动量喷注产生过程的pQCD计算和相应的部分子强子化方案,较好地再现了高能区实验的结果.平滑地外推到超高能区,预言了非弹性度随能量下降的趋势. 相似文献
10.
11.
This review of low-p
T proton-proton physics at low luminosity at the large hadron collider (LHC) should cover all LHC experiments, but in practice,
is mainly related to ALICE, for reasons which will be explained. However, the relevance to other LHC experiments is clear,
as low-pT. phenomena represent an important component of the background to their high-pT. phenomena which needs to be calibrated. The ALICE collaboration will study proton-proton collisions as part of their heavy-ion
programme, where most signals are relative to the proton-proton system. In addition, the ALICE detector’s unique acceptance
at low pT as well as its unique particle identification capability will make it possible to carry out a program of genuine proton-proton
physics complementary to those of other LHC experiments. 相似文献
12.
We examine the consequences of a variable (density-dependent) bag pressure term and a fixed hadronic size in the phenomenological
MIT bag model for hadron spectroscopy. Mass spectrum of the low-lying baryons and mesons, baryon magnetic moments and the
hadron mass splittings are estimated. These are found to be in closer agreement with experiment than the MIT results. 相似文献
13.
ZHU Shi-Lin GAO Chong-Shou 《理论物理通讯》2006,46(2):291-293
We point out that the large pp^- coupling of X(1835) and the suppression of the three-body strange final states strongly indicate that X(1835) may be a pp^- baryonium. We also point out that the branching ratio of X(1835) →ηππ should be bigger than that of X(1835) →η′ππ. We suggest BES search X(1835) in the ηππ channel Finally, X(1835) may be used a tetraquark generator if X(1835) is really established as a baryonium state. 相似文献
14.
15.
Michael Dittmar 《Pramana》2000,55(1-2):151-160
The latest unsuccessful Higgs searches at LEP have pushed its mass well into the domain where significant signals can be expected from the LHC experiments. The most sensitive LHC Higgs signatures are reviewed and the discovery year is estimated as a function of the Higgs mass. Finally, we give some ideas about: ‘What might be known about the production and decays of a SM Higgs boson’ after 10 years of LHC? 相似文献
16.
Basic assumptions used in the analysis of elastic differential cross section data will be discussed and the arguments for the transparency of nucleons will be analyzed. It will be shown that the transparency of nucleon is a direct consequence when a weak t dependence of hadronic amplitude phase is used in analogy with optics. The phase t dependence may be hardly uniquely determined from elastic scattering data, being only partially limited by the Coulomb-hadronic interference existing in a very narrow region of small |t| values. The given situation will be demonstrated with the help of data for
collisions at 541 GeV; nucleons being transparent or having hard cores may be admitted by the elastic data themselves. However, when further characteristic of inelastic and elastic processes are compared, the nucleon with hard core should be preferred. The most probable characteristics of nucleon structure derived from the data will be presented. 相似文献
17.
按照夸克组合模型, 通过分析给出e+e-→q0q0→h′s过程轻味夸克jet事例中各种粒子的产生几率以及相对比值. 给出奇异、非奇异粒子多重数比率γ与奇异抑制因子λ之间的关系, 不需要假设奇异抑制因子改变, 能够解释粒子比率增大的实验. 相似文献
18.
We analyze the spectra of pions and protons in heavy-ion collisions at relativistic energies from 2 A GeV to 65+65 A GeV by
using a jet-implemented hadron-string cascade model. In this energy region, hadron transverse mass spectra first show softening
until SPS energies, and re-hardening may emerge at RHIC energies. Since hadronic matter is expected to show only softening
at higher energy densities, this re-hardening of spectra can be interpreted as a good signature of the quark-gluon plasma
formation 相似文献
19.
回顾了近期BES和CLEOc利用正负电子对撞机采集的J/ψ, ψ′和ψ′′数据得到的强子谱与粲偶素衰变方面的部分研究结果. 重点分析了对于轻标量粒子的实验研究, 包括利用J/ψ的辐射衰变和强衰变, ψ′的强衰变和χc的强衰变得到的结果, 并对有关粒子的性质进行了评述, 对用以获得这些信息的实验方法作了评论, 提出了改进的建议; 还重点总结了矢量粲偶素粒子衰变“ρπ疑难”相关的实验和理论研究成果, 并对进一步的实验和理论研究提出了建议. 这些结果对于理解量子色动力学在低能区的应用有很大帮助. 相似文献