作者机构：
[Feng, SQ; Liu, F; Liu, LS] Huazhong Normal Univ, Inst Particle Phys, Wuhan 430079, Peoples R China.
通讯机构：
[Feng, SQ] H;Huazhong Normal Univ, Inst Particle Phys, Wuhan 430079, Peoples R China.
摘要：
A model with nonuniform flow in the longitudinal direction is proposed for the relativistic heavy ion collisions and compared with the 14.6AGeV/c Si-Al and 10.8AGeV/c Au-Au collision data. The stronger influence of transparency on the distribution of heavier produced particles and the larger stopping in the heavier collision system are accounted for by using a new geometrical parametrization picture. The central dips in the proton and deuteron rapidity distributions for Si-Al collision are reproduced.
期刊：
HIGH ENERGY PHYSICS AND NUCLEAR PHYSICS-CHINESE EDITION,2001年25(6):465-475 ISSN：0254-3052
通讯作者：
Rong, G
作者机构：
[Rong, G] Chinese Acad Sci, Inst High Energy Phys, Beijing 100039, Peoples R China.;Univ Sci & Technol China, Dept Modern Phys, Anhua 230026, Peoples R China.;Shandong Univ, Dept Phys, Jinan 250100, Peoples R China.;Hangzhou Univ, Dept Phys, Hangzhou 310028, Peoples R China.;Shanghai Jiao Tong Univ, Dept Appl Phys, Shanghai 200030, Peoples R China.
通讯机构：
[Rong, G] C;Chinese Acad Sci, Inst High Energy Phys, Beijing 100039, Peoples R China.
关键词：
Beijing Electron Positron Collider (BEPC);Beijing Spectrometer (BES);D-s(+) Meson;D-s(+) single tag;branching fraction;production cross section;radiative correction
摘要：
Measurement of the production cross section of the D-s(+) D-s(-) in e(+) e(-) annihilation at the Center-of-Mass Energy of roots = 4.03 GeV is reported in the paper. The cross section for the D: DI production has been measured using a data sample of 22.3 pb(-1) collected with BES detector at BEPC e(+) e(-) collider. The D-s(+) measons are reconstructed in the phi pi (+), (K*(0)) over barK(+) and (K-0) over barK(+) decay modes. A total number of 94 +/- 13 singly tagged D-s(+) events is obtained from the three modes. This yelds the cross section value sigmaD(s)(prod+)D(s)(-) = (451 +/- 63 +/- 118)pb for D-s(+) D-s(-) production. Based on the numbers of singly tagged D-s(+) events for each of the three decay modes,the decay branching fractions for D-s(+) --> (K*(0)) over barK(+) and (K-0) over barK(+) have been determined to be (3.02 +/- 0.94 +/- 0.91)% and (3.28 +/- 1.22 +/- 0.94)%, respectively.
通讯机构：
[Liu, FM] H;Huazhong Normal Univ, Inst Particle Phys, Wuhan 430079, Peoples R China.
关键词：
high energy nucleus-nucleus collision;statistical fluctuation;Monte Carlo simulation;erraticity
摘要：
It is demonstrated using Monte Carlo simulation that in different nucleus-nucleus collision samples, the increase of the fluctuation of event factorial moments with decreasing phase space scale, called erraticity, is still dominated by the statistical fluctuations. This result does not depend on the Monte Carlo models. Nor does it depend on the concrete conditions, e.g., the collision energy, the mass of colliding nuclei, the cut of phase space, etc. This means that the erraticity method is sensitive to the appearance of novel physics in the central collisions of heavy nuclei. (C) 2001 Elsevier Science B.V. All rights reserved.
摘要：
Transverse momentum event-by-event fluctuations are studied within the string-hadronic model of high energy nuclear collisions, LUCIAE. Data on non-statistical PT fluctuations in p+p interactions are reproduced. Fluctuations of similar magnitude are predicted for nucleus-nucleus collisions, in contradiction to the preliminary NA49 results. The introduction of a string clustering mechanism (Firecracker Model) leads to a further, significant increase of PT fluctuations for nucleus-nucleus collisions. Secondary hadronic interactions, as implemented in LUCIAE, cause only a small reduction of PT fluctuations.
作者机构：
[Liu, F; Liu, LS; Liu, RM] Huazhong Normal Univ, Inst Particle Phys, Wuhan 430079, Peoples R China.
通讯机构：
[Liu, F] H;Huazhong Normal Univ, Inst Particle Phys, Wuhan 430079, Peoples R China.
摘要：
The qualitative difference between the anomalous scaling properties of hadronic final states in soft and hard processes of high-energy collisions is studied in some detail. It is pointed out that the experimental data of e+e− collisions at Ec.m.=91.2 GeV from DELPHI indicate that the dynamical fluctuations in e+e− collisions are isotropical, in contrast with the anisotropical fluctuations oberserved in hadron-hadron collision experiments. This assertion is confirmed by the Monte Carlo simulation using the JETSET 7.4 event generator.
期刊：
INTERNATIONAL JOURNAL OF MODERN PHYSICS A,1998年13(12):1969-1979 ISSN：0217-751X
通讯作者：
Feng, L
作者机构：
[Feng, L] Huazhong Normal Univ, Inst Particle Phys, Wuhan 430079, Peoples R China.
通讯机构：
[Feng, L] H;Huazhong Normal Univ, Inst Particle Phys, Wuhan 430079, Peoples R China.
摘要：
According to the cone definition of the jet we propose a practical and effective algorithm to identify jets. Through comparison between the Monte Carlo samples with and without jet(s), the following observations are made. Contrary to what is expected, most of the jetty events do not have high multiplicity. The distributions of multiplicity and (p) over bar t have long tails for the whole event sample because of (mini)jet production, but no such tail for a no-jet event subsample. The average transverse momentum per event (p) over bar t and multiplicity n are positively correlated for the whole event sample, and negatively correlated for the jetty event subsample. Two ratios are introduced to describe the "degree of hardness" of each event and are found to be correlated positively with (p) over bar t, but negatively with multiplicity, indicating that (p) over bar t is a better characteristic parameter to describe the event hardness than multiplicity.
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.
