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寻找顶夸克的漫长过程 被引量:1
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作者 何景棠 《物理学进展》 CSCD 北大核心 2003年第4期466-472,共7页
 本文描述寻找顶夸克的漫长过程。从70年代末开始,美国的PEP,德国的PETRA,80年代日本的TRISTAN,欧洲核子中心CERN的SP PS质子反质子对撞机,90年代的CERN的LEP大型电子正电子对撞机,最后于1997年才由美国费米国家实验室的D0和CDF国际合...  本文描述寻找顶夸克的漫长过程。从70年代末开始,美国的PEP,德国的PETRA,80年代日本的TRISTAN,欧洲核子中心CERN的SP PS质子反质子对撞机,90年代的CERN的LEP大型电子正电子对撞机,最后于1997年才由美国费米国家实验室的D0和CDF国际合作组找到了顶夸克存在的证据,并给出了顶夸克的质量为:174.3±3.2±4.0GeV。人们可以从这段历史获得有益的启示。 展开更多
关键词 顶夸克 电子正电子对撞机 质子反质子对撞机 粒子物理学 强子 中性流反应 味道改变 强子 轻子
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<i>PP</i>and <i>P<span style='text-decoration:overline;'>P</span></i>Multi-Particles Production Investigation Based on CCNN Black-Box Approach
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作者 El-Sayed A. El-Dahshan 《Journal of Applied Mathematics and Physics》 2017年第6期1398-1409,共12页
The multiplicity distribution (P(nch)) of charged particles produced in a high energy collision is a key quantity to understand the mechanism of multiparticle production. This paper describes the novel application of ... The multiplicity distribution (P(nch)) of charged particles produced in a high energy collision is a key quantity to understand the mechanism of multiparticle production. This paper describes the novel application of an artificial neural network (ANN) black-box modeling approach based on the cascade correlation (CC) algorithm formulated to calculate and predict multiplicity distribution of proton-proton (antiproton) (PP and PP ) inelastic interactions full phase space at a wide range of center-mass of energy . In addition, the formulated cascade correlation neural network (CCNN) model is used to empirically calculate the average multiplicity distribution nch> as a function of . The CCNN model was designed based on available experimental data for = 30.4 GeV, 44.5 GeV, 52.6 GeV, 62.2 GeV, 200 GeV, 300 GeV, 540 GeV, 900 GeV, 1000 GeV, 1800 GeV, and 7 TeV. Our obtained empirical results for P(nch), as well as nch> for (PP and PP) collisions are compared with the corresponding theoretical ones which obtained from other models. This comparison shows a good agreement with the available experimental data (up to 7 TeV) and other theoretical ones. At full large hadron collider (LHC) energy ( = 14 TeV) we have predicted P(nch) and nch> which also, show a good agreement with different theoretical models. 展开更多
关键词 Proton-Proton and proton-antiproton Collisions Multiparticle PRODUCTION Multiplicity Distributions Intelligent Computational Techniques CCNN-Neural Networks BLACK-BOX Modeling Approach
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On Self-Similarity of Top Production at Tevatron
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作者 Mikhail Tokarev Imrich Zborovsky 《Journal of Modern Physics》 2012年第8期815-820,共6页
This paper presents the results of analysis of the D? 1.0 fb-1 data on top-quark differential cross section measurements at the Fermilab Tevatron collider at √s= 1960 GeV in the framework of z-scaling approach. The f... This paper presents the results of analysis of the D? 1.0 fb-1 data on top-quark differential cross section measurements at the Fermilab Tevatron collider at √s= 1960 GeV in the framework of z-scaling approach. The flavor independence of scaling function Ψ(z)observed in pp and pp interactions over a wide collision energy range √s= 19-1960 GeV has been verified. This property of Ψ(z) was found for different hadrons – from π-mesons up to Υ particles. The flavor independence of Ψ(z) is used as indication on self-similarity of the top-quark production. A tendency to saturation of Ψ(z) at low z for top-quark production has been confirmed. Momentum fraction x1 of the incoming (anti)protons as a function of the scaled transverse momentum pT/m and masses of heavy mesons is studied. We anticipate that the data on low- and high-pT inclusive spectra of the top-quark production at the Tevatron and LHC energies could be of interest to verify self-similarity over a wide range of masses and different flavor content of produced particles. 展开更多
关键词 Inelastic Cross Section proton-antiproton Collisions Top Production Scaling SELF-SIMILARITY
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X(1835):Skyrme模型中的质子-反质子束缚态(英文)
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作者 闫沐霖 《高能物理与核物理》 EI CSCD 北大核心 2006年第11期1141-1150,共10页
BES(北京谱仪)发现了奇特粒子态X(1835).述评近年来把X(1835)解释为Skyrme模型中的N(N|-)-重子偶素的工作.有2个证据支持这种解释:1)存在N(N|-)-经典Skyrmion解,其结合能为-10MeV;2)这种Skyrmion-重子偶素的衰变是由X(1835)中的p-(p|-... BES(北京谱仪)发现了奇特粒子态X(1835).述评近年来把X(1835)解释为Skyrme模型中的N(N|-)-重子偶素的工作.有2个证据支持这种解释:1)存在N(N|-)-经典Skyrmion解,其结合能为-10MeV;2)这种Skyrmion-重子偶素的衰变是由X(1835)中的p-(p|-)经由量子隧穿而湮没所引起的,因此最可几的衰变道是X(1835)→η4π或X(1835)→η′2π.这些导致了对BES实验数据的合理解释,特别是关于X(1835)最可几的衰变模式的预言.该预言对实验有价值. 展开更多
关键词 奇特粒子态 质子-反质子束缚态 SKYRME模型 质子-反质子湮没 X(1835)衰变
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北京谱仪(BESⅡ)上p和■鉴别的研究
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作者 李会红 刘峰 +2 位作者 李金 苑长征 王至勇 《高能物理与核物理》 CSCD 北大核心 2003年第8期659-664,共6页
以北京谱仪(BES)上常用的3种粒子鉴别方法为基础,充分利用BESⅡ所获取的R值扫描、J/ψ和ψ′数据中p,(?)以及其他带电粒子样本,对动量范围在0.3—1.2GeV的p和(?)鉴别方法进行分析研究,找到BESⅡ上p和(?)的最佳鉴别方法:动量低于0.6GeV只... 以北京谱仪(BES)上常用的3种粒子鉴别方法为基础,充分利用BESⅡ所获取的R值扫描、J/ψ和ψ′数据中p,(?)以及其他带电粒子样本,对动量范围在0.3—1.2GeV的p和(?)鉴别方法进行分析研究,找到BESⅡ上p和(?)的最佳鉴别方法:动量低于0.6GeV只用dE/dx实现粒子鉴别,动量高于0.6GeV可用TOF或联合鉴别的方法,并给出p,(?)的鉴别效率以及本底的混入比例。 展开更多
关键词 北京谱仪 BESⅡ 粒子鉴别 粒子探测 质子 反质子
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