相对论重离子碰撞的现状及展望

Introduction
In high energy interactions, the study of non-statistical fluctuations have entered into a new era since Bialas and Peschanski(NP B273(1986) 703) introduced an attractive methodology to study non-statistical fluctuations in multiparticle production. They suggested that the scaled factorial moment Fq has a growth following a power law with decreasing phase space interval size and this feature signals the onset of intermittency in the context of high energy interactions. This scaled factorial moment method has the feature that it can measure the non-statistical fluctuations avoiding the statistical noise. Up to now, most of the analysis have been carried out in the relativistic produced particles with the common belief that these particles are the most informative about the reaction dynamics and thus could be effective in revealing the underlying physics of relativistic nucleus-nucleus collisions. However, the physics of nucleus-nucleus collisions at high energies is not yet conclusive and therefore all the available probes need to thoroughly exploited towards meaningful analysis of experimental data.
1. Introduction
In the analysis of intermittency most of the studies are performed in the onedimensional space only, but the real process occurs in three dimensions. So onedimensional analysis is not sufficient enough to make any comment on the complete dynamical fluctuations pattern. According to Ochs (PL B247(1990) 101), in a lowerdimensional projection the fluctuations will be reduced by the averaging process. In two-dimensional analysis generally the phase space are divided equally in both directions assuming that the phase spaces are isotropic in nature. Consequently selfsimilar fluctuations are expected. It may happen that the fluctuations are anisotropic and the scaling behavior is different in different directions giving rise to self-affine scaling. So far only a few works have been reported where the evidence of self-affine multiparticle production is indicated by the data(Ghosh et al., EPJ A14(2002) 77, PR C66(2002) 047901, JP G29(2003) 983, IJMP E13(2004) 1179, MPL A22(2007) 1759, Wang et al., PL B410(1997) 323, Wu and Liu, PRL 70(1993) 3197).
Evidence of self-affine target fragmentation process in 197Au-AgBr interactions at 10.7 A GeV
D.H. Zhang, F. Wang, J.X. Cheng, B. Cheng, Q. Wang, H.Q. Zhang, R. Xu
1. Introduction
In relativistic heavy ion induced nuclear emulsion interactions, the target
fragmentation produces highly ionizing particles responsible for heavy tracks which are subdivided into gray and black tracks. The gray tracks are the medium-energy (30-400 MeV) knocked-out target protons (or recoiled protons) with range 3 mm and velocity 0.3β0.7. They are supposed to carry some information about the interaction dynamics because the time scale of the emission of these particles is of the same order (10-22s) as that of the produced particles. The general belief about these recoiled protons is that they are the low energy part of the internuclear cascade formed in high energy interactions. The black tracks with range <3 mm and velocity β<0.3 are attributed to evaporation from highly excited nuclei in the thermodynamically equilibrium state. In the rest system of the target nucleus, the emission direction of the evaporated particles is distributed isotropically.
Institute of Modern Physics, Shanxi Normal University Linfen 041004, China Sept. 2, 2008
1、Introduction 2、Experimental details 3、Method of Study 4、Experimental Results