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e + e – 碰撞中喷注内部的 非线性动力学特性的研究. 报告人 : 陈 刚 （中国地质大学 数学与物理学院 物理系） 2 006 年 10 月 29 日. OUTLINE 1 . Introduction 2. The dynamical fluctuations inside 2-jets 3. The dynamical fluctuations inside 3-jets 4. The dynamical fluctuations inside single-jets 5. Conclusion. 1. Introduction.
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e+ e– 碰撞中喷注内部的非线性动力学特性的研究 报告人:陈 刚（中国地质大学 数学与物理学院 物理系）2006年10月29日
OUTLINE 1. Introduction 2. The dynamical fluctuations inside 2-jets 3. The dynamical fluctuations inside 3-jets 4. The dynamical fluctuations inside single-jets 5. Conclusion
1. Introduction 1.1 The evolutive processin e+e- collisions QCD —— The basic theory of strong interaction Question：• It is hard difficulty to calculate in soft processes by QCD； • The partons haven’t been right observed as color confinement.
1.2 Jet finding • 2-jet event in 1975, EC = 6 GeV； • 3-jet event in 1979, Ec = 17—30 GeV
1.4 The method described non-linear dynamical fluctuation • NFM can characterize the dynamical fluctuation • Saturation exponent —— the parameter of dynamical fluctuation • Ifpt = = yisotropy Ifpt y，anisotropy
1.5 The method described non-linear dynamical fluctuation Self-affine fractal pt y Self-similar fractal pt = = y h-h collisionpt = yAnisotropy in space e+e- collisionpt = = yIsotropy in space
2. The dynamical fluctuations inside 2-jets L.S. Liu, G. Chen and Q.H. Fu ，Phys. Rev. D63（2001）G. Chen，K.S. Zhang and L.S. Liu L，SCIENCE IN CHINA G 46(3)（2003）
The dynamical fluctuations inside 2-jetsChen Gang, Hu Yuan, Liu Lianshou, W. Kittel, W.J. Metzger(L3 Collab.)XXXI ISMD, Datong Sept. 2001, (WORLD SCIENTIFIC). The result is similar as same as MC simulation, exist a transition point
2. The dynamical fluctuations inside 2-jets · Analysis of the result from 2-jet sub-sample It is the boundary of physical jet or circular jet.
3. The dynamical fluctuations inside 3-jets Chen Gang，Yu Meiling and Liu Lianshou, Submiting to Phys. Rev.D • Appropriate scale of jet production GeV (Jetset7.4), GeV(Herwig5.9) • Phase space: -5 < y <5, 0< pt< 3GeV, 0 < φ< 2π• The plot of γ～kt cut(ycut) According to the symmetry of QCD Lagrangian, the gluon emission is isotropic, so the dynamical symmetry of 3-jet events is spherical. .
4. The dynamical fluctuations inside single-jets Chen Gang，Yu Meiling and Liu Lianshou, Submiting to Phys. Rev.D • The jet axis as the z axis • Phase space: 0 < y <5, 0< pt< 3GeV, 0 < φ< 2π• The plot of γ～kt cut(ycut) • The dynamical fluctuation in azimuth appear GeV (Jetset7.4) GeV (Herwig5.9)
4. The dynamical fluctuations inside single-jets Chen Gang，Yu Meiling and Liu Lianshou, Submiting to Phys. Rev.D • The jet axis as the z axis • Phase space: 0 < y <5, 0< pt< 3GeV, 0 < φ< 2π• The plot of γ～kt cut(ycut) • The dynamical fluctuation in azimuth appear • Obtain a scale GeV (Jetset7.4) GeV (Herwig5.9)
5. Conclusion . • Listed the scales found in Table 1 The coincidence of the scales obtained from different origins is remarkable. All of them are related to jet production, so we give them a unique name . jet production scale: GeV
5. Conclusion • The jets in 2-jet events produced with is circular with • respect to dynamical fluctuations, i.e. the dynamical fluctuations in these jets is circular in the transverse plane. These jets have axial dynamical symmetry as expected by QCD. 2. When a third jet is produced with the resulting 3-jet system is isotropic in consistent with QCD expectation. 3. Inside a single jet, when it emits a gluon with , the dynamical fluctuations in azimuthal angle appear suddenly inside this jet, which means that the jet emitting gluon with is fully developed, and the emitted gluon is hard enough to be the ``mother'' of a new jet.
