高能非线性现象研究的新进展

经典色动力学有混沌解,但是量子混沌是一个困难的理论问题,因而高能物理中的非线性目前还只能用唯象方法进行研究.80年代末,实验观察到多粒子未态相空间中有局域大起伏,激发了对高能非线性现象——间歇与分形研究的热潮.实验发现,一维阶乘矩有饱和现象,这被解释为高维间歇投影到低维的结果;但是,三维阶乘矩也并没有严格的反常标度性.这一困难在一段时间里曾使得间歇(分形)的研究陷于停顿.以后发现,其原因在于高能多粒子未态相空问高度各向异性,因而相应的分形是自仿射分形.只有对相空间进行正确的各向异性分割,才能观察到反常标度性.这一预言已在NA22和NA27的实验数据中得到证实,成功地观察到了反常标度性,从而使高能非线性的研究取得突破性进展.本文介绍这一进展,并作一些讨论.

New Progress in the Study of High Energy Non-Linear Phenomena

Classical Chromodynamics has chaos solution. But quantum chaos is a verydifficult theoretical problem. Therefore, at present the non-linear study in high energyPhysics can only be carried on using phenomenological methods. By the end ofeighties, large local fluctuations were observed in experiments, which shmulatedextensive study on high energy non-linear phenomena- intermittency and fractal. Itwas observed experimentally that l-dimensional factorial moments tend to saturate.This was explained as the result of projechon of higher-dimensional intermittency intolower dimension. However, even in 3-dimension the factorial moments do not obey astrict scaling law. ms difficulty has brought the study to a standstill. Later, it wasrecognized that the reason lies in the fact that the phase space of high energymultiparticle final states is highly anisotuopy and therefore the corresponding fractal isself-affine. The anomalous scaling can be observed when and only when the phasespace is divided in a correct anisotropical way. Thi predichon has been verified inthe experimental data from NA22 and NA27. The anomalous scaling in theseexperiments has been observed successfully, making a breakthrough in high energynon-linear study. This progress is reviewed in mis paper together with some commentsand discussions.