Intermittency in Individual Events

a Recent discussion of the possibility to study intermittency in individual events of high multiplicity by A. Bialas and myself is reported. In the framework of α−model it is found that, for a cascade long enough, the dispersion of intermittency exponents obtained from individual events is fairly small. This fact opens the possibility to study the distribution of the intermittency parameters characterizing the cascades seen (by observing intermittency) in particle spectra. 1 Introduction The aim of this talk is to present the results of the investigation 1 of intermit-tency effects in individual events of high multiplicity. The original suggestion of intermittent behaviour in multiparticle production at high energies 2 was based on analysis of a single event of very high multiplicity recorded by the JACEE collaboration 3. It was soon realized, however, that the idea can be applied to events of any multiplicity provided that a proper averaging of the distributions is performed 4. This led to many successful experimental studies of intermittency 5 , and allowed to express the effect in terms of the multipar-ticle correlation functions 6. It should be realized, however, that the averaging procedure, apart from clear advantages, brings also a danger of overlooking some interesting effects if they are present only in a part of events produced in high-energy collisions. It seems therefore interesting to study intermittency parameters of individual events, hoping that they may indicate some specific production mechanism (a typical example is the production of quark-gluon plasma which is expected to be characterized by specific intermittency exponents , see e.g. 7 , and certainly not expected to be present in each event). Such studies should necessarily be restricted to high-multiplicity events because only there one may expect the statistical fluctuations to be under control. However, even neglecting statistical errors due to the finite number of particles , there remains an intrinsic uncertainty of the intermittency parameters: the cascade responsible for intermitent behaviour has different realizations in different events. As the intermittency exponents determined from different realizations of the same random cascade are expected to scatter around the average, the method has a finite resolution with respect to the parameters of a