对双重重子产生机制的研究有助于更好地研究微扰和非微扰QCD理论。对γγ对撞机上双重重子Ξbb的产生做了进一步研究,考虑了bb处于色三重态和色六重态的共同贡献。结果发现：质心系能量在91-1 000 Ge V变动时,Ξbb的产生率会随着质心系...对双重重子产生机制的研究有助于更好地研究微扰和非微扰QCD理论。对γγ对撞机上双重重子Ξbb的产生做了进一步研究,考虑了bb处于色三重态和色六重态的共同贡献。结果发现：质心系能量在91-1 000 Ge V变动时,Ξbb的产生率会随着质心系能量的提高而降低。但是由于积分亮度的不同,不同对撞能量下Ξbb产生的事例数大致相同。选择合适初态粒子束的极化度能有效提高Ξbb的产生率,在某些能量对撞点,初始态粒子束的极化度可以将Ξbb的产生率提高17%左右。展开更多
The top-pair production in association with a Z^0-boson at a photon-photon collider is an important processin probing the coupling between top-quarks and vector boson and discovering the signature of possible new phys...The top-pair production in association with a Z^0-boson at a photon-photon collider is an important processin probing the coupling between top-quarks and vector boson and discovering the signature of possible new physics.Wedescribe the impact of the complete supersymmetric QCD (SQCD) next-to-leading order (NLO) radiative correctionson this process at a polarized or unpolarized photon collider,and make a comparison between the effects of the SQCDand the standard model (SM) QCD.We investigate the dependence of the lowest-order (LO) and QCD NLO correctedcross sections in both the SM and minimal supersymmetric standard model (MSSM) on colliding energy s^(1/2) in differentpolarized photon collision modes.The LO,SM NLO,and SQCD NLO corrected distributions of the invariant mass oftt-pair and the transverse momenta of final Z^0-boson are presented.Our numerical results show that the pure SQCDeffects in γγ→ ttZ^0 process can be more significant in the ++ polarized photon collision mode than in other collisionmodes,and the relative SQCD radiative correction in unpolarized photon collision mode varies from 32.09% to-1.89%when s^(1/2) goes up from 500 GeV to 1.5 TeV.展开更多
文摘对双重重子产生机制的研究有助于更好地研究微扰和非微扰QCD理论。对γγ对撞机上双重重子Ξbb的产生做了进一步研究,考虑了bb处于色三重态和色六重态的共同贡献。结果发现：质心系能量在91-1 000 Ge V变动时,Ξbb的产生率会随着质心系能量的提高而降低。但是由于积分亮度的不同,不同对撞能量下Ξbb产生的事例数大致相同。选择合适初态粒子束的极化度能有效提高Ξbb的产生率,在某些能量对撞点,初始态粒子束的极化度可以将Ξbb的产生率提高17%左右。
基金Supported in part by the National Natural Science Foundation of China under Grant Nos.10575094 and 10875112the National Science Fund for Fostering Talents in Basic Science under Grant No.J0630319+1 种基金Specialized Research Fund for the Doctoral Program of Higher Education (SRFDP) under Grant No.20050358063a Special Fund Sponsored by Chinese Academy of Sciences
文摘The top-pair production in association with a Z^0-boson at a photon-photon collider is an important processin probing the coupling between top-quarks and vector boson and discovering the signature of possible new physics.Wedescribe the impact of the complete supersymmetric QCD (SQCD) next-to-leading order (NLO) radiative correctionson this process at a polarized or unpolarized photon collider,and make a comparison between the effects of the SQCDand the standard model (SM) QCD.We investigate the dependence of the lowest-order (LO) and QCD NLO correctedcross sections in both the SM and minimal supersymmetric standard model (MSSM) on colliding energy s^(1/2) in differentpolarized photon collision modes.The LO,SM NLO,and SQCD NLO corrected distributions of the invariant mass oftt-pair and the transverse momenta of final Z^0-boson are presented.Our numerical results show that the pure SQCDeffects in γγ→ ttZ^0 process can be more significant in the ++ polarized photon collision mode than in other collisionmodes,and the relative SQCD radiative correction in unpolarized photon collision mode varies from 32.09% to-1.89%when s^(1/2) goes up from 500 GeV to 1.5 TeV.
文摘讨论关于在ILC用gamma gamma到Z过程检验非对易时空能标(原文发在hep-ph/0604115).在通常时空量子场论中,由杨氏定理可知一个自旋为1的粒子不可能衰变为两个光子.但在非对易时空中此过程是允许的.因此这个过程能作为检验非对易时空的工具.ILC的光子对撞模式能实现这个过程.如果总亮度能达到500fb^(-1),我们证明对Gamma(z to gamma gamma)宽度的测量精度将比现有限制(<5.2×10^(-5)GeV)好3—4个数量级.对非对易时空能标的检测可高达几个TeV.
