摘要：
The constraint structure of the induced 2D-gravity with the Weyl and area-preserving diffeomorphism invariances is analysed in the ADM formulation. It is found that when the area-preserving diffeomorphism constraints are kept, the usual conformal gauge does not exist, whereas there is the possibility to choose the so-called “quasi-light-cone” gauge, in which besides the area-preserving diffeomorphism invariance, the reduced Lagrangian also possesses the SL(2, R) residual symmetry. This observation indicates that the claimed correspondence between the SL(2, R) residual symmetry and the area-preserving diffeomorphism invariance in both regularisation approaches does not hold. The string-like approach is then applied to quantise this model, but a fictitious non-zero central charge in the Virasoro algebra appears. When a set of gauge-independent SL(2, R) current-like fields is introduced instead of the string-like variables, a consistent quantum theory is obtained, which means that the area-preserving diffeomorphism invariance can be maintained at the quantum level.
期刊：
PROCEEDINGS OF THE XXVI INTERNATIONAL SYMPOSIUM ON MULTIPARTICLE DYNAMICS,1997年:343-350
通讯作者：
Liu, LS
作者机构：
[Wu, YF; Liu, LS] Huazhong Normal Univ, Inst Particle Phys, Wuhan, Peoples R China.
通讯机构：
[Liu, LS] H;Huazhong Normal Univ, Inst Particle Phys, Wuhan, Peoples R China.
摘要：
It is argued that the scaling property of higher dimensional normalized factorial moments depends essentially on the different ways of phase space division. The later can be characterized by the log ratio of partition number in different directions of phase space. Two examples are given. Firstly, a self-affine analysis of factorial moments was carried out on the NA22 data for pi(+)p and K(+)p collisions at 250 GeV/c. It turns out that the Hurst exponent is only one half when the longitudinal direction is compared to the transverse ones, providing a first experimental evidence on the anisotropy of dynamical fluctuation in multiparticle production. A discussion on the similar analysis for heavy ion collision data is presented as a second example. The experimentally observed strong upward-bending of the logarithm of factorial moments versus that of the phase space partition number in higher-dimensional phase space of nucleus-nucleus collisions is shown to be due to the superposition of elementary collision processes in these collisions. A trigger condition for the search of QGP is proposed basing on this phenomenon.
摘要：
The scaled factorial moments in QGP phase transitions are studied analytically by the extended Ginzburg-Landau model. The dependence of lnF(q) on phase space interval is different for the first-and second-order QGP phase transitions. When lnF(q) are fitted to polynomials of X drop delta(1/3), the relative sign between the fitted coefficients of X and b(q,1) calculated theoretically can be used to judge the order of phase transitions. Two sets of experimental data are reanalysed and the phase transitions are the first order for one set of data I,ut the second order for another.
期刊：
EUROPEAN PHYSICAL JOURNAL C,1997年73(3):535-539 ISSN：1434-6044
通讯作者：
Liu, LS
作者机构：
[Liu, LS; Zhang, Y; Deng, Y] Institute of Particle Physics, Hua-Zhong Normal University, Wuhan, People’s Republic of China
通讯机构：
[Liu, LS] H;HUA ZHONG NORMAL UNIV,INST PARTICLE PHYS,WUHAN 430070,PEOPLES R CHINA.
摘要：
The experimental results on the falling down of scaled factorial moments in azimuthal variable phi is studied in some detail. It is shown that this phenomenon may be referred to the influence of transverse momentum conservation. The existing experimental data from DELPHI, EMU08, NA22 and UA1 are successfully explained. Various methods are proposed to partly eliminate this influence and rule out the 'falling down' of factorial moments.
作者机构：
[Liu, FY; Liu, F; Liu, LS; Liu, M] Huazhong Normal Univ, Inst Particle Phys, Wuhan 430070, Peoples R China.
通讯机构：
[Liu, M] H;Huazhong Normal Univ, Inst Particle Phys, Wuhan 430070, Peoples R China.
关键词：
high energy collision;multiparticle production;hard processes;jet;"cone algorithm"
摘要：
The "cone algorithm" for jet identification is studied in some detail. Two schemes are proposed to identify jets using the momenta of final state particles. Making use of the hadron-hadron collision data sample produced by LUND-PYTHIA Monte Carlo generator, the two schemes are tested and compared with each other. An effective scheme to identify jets is obtained.
期刊：
Monthly Notices of the Royal Astronomical Society,1997年288(4):965-972 ISSN：0035-8711
通讯作者：
Yang, LT
作者机构：
HUAZHONG NORMAL UNIV,DEPT PHYS,WUHAN 430070,PEOPLES R CHINA.;HUAZHONG NORMAL UNIV,INST ASTROPHYS,WUHAN 430070,PEOPLES R CHINA.;[Yang, LT] MAX PLANCK SOC,RES UNIT DUST STAR FORMING REG,SCHILLERGASSCHEN 3,D-07745 JENA,GERMANY.
通讯机构：
[Yang, LT] M;MAX PLANCK SOC,RES UNIT DUST STAR FORMING REG,SCHILLERGASSCHEN 3,D-07745 JENA,GERMANY.
作者机构：
[Li, JR; Zhang, XF] Institute of Particle Physics, Huazhong Normal University, Wuhan 430070, China
通讯机构：
[Zhang, XF] H;HUA ZHONG NORMAL UNIV,INST PARTICLE PHYS,WUHAN 430070,PEOPLES R CHINA.
摘要：
The transport equations for gluon plasma are studied beyond the linear approximation by the multiple time-scale method. And the nonlinear Landau damping rate for the long-wavelength plasmon in gluon plasma is calculated.
作者机构：
CHINA CTR ADV SCI & TECHNOL, WORLD LAB, BEIJING 100080, PEOPLES R CHINA.;HUAZHONG NORMAL UNIV, INST PARTICLE PHYS, WUHAN 430070, PEOPLES R CHINA.;[Jia, Y] HUAZHONG NORMAL UNIV, DEPT PHYS, WUHAN 430070, PEOPLES R CHINA.
通讯机构：
[Jia, Y] H;HUAZHONG NORMAL UNIV, DEPT PHYS, WUHAN 430070, PEOPLES R CHINA.
摘要：
An approximate Fokker-Planck equation for a general one-dimensional system driven by correlated noises is derived; the correlation times of the correlations between the noises are nonzero. The steady-state properties of the bistable kinetic model are analyzed. We find the following. (1) In the α−D parameter plane ( α and D are the additive noise and multiplicative noise intensities, respectively), the area of the bimodal region of the stationary probability distribution (SPD) is contracted as λ is increased ( λ is the strength of the correlations between noises), but the area of the bimodal region of the SPD is enlarged as τ is increased ( τ is the correlation time of the correlations between noises). (2) λ and τ play opposing roles in the transition of the SPD of the system. (3) For the case of perfectly correlated noises ( λ=1), there is not the phenomenon of the critical ratio ( αD=1) which was shown by Wu, Cao, and Ke [Phys. Rev. E 50, 2496 (1994)]. (4) The change of the mean of the state variable is very remarkable in the small τ and large λ regimes. (5) The normalized variance of the state variable increases with increasing τ, but decreases with increasing λ.
