PHYSICAL REVIEW C VOLUME 49, NUMBER 3 MARCH 1994 Taro charged particle and transverse energy correlations in Si+Pb collisions at 14. 6A Gev/c J. Barrette, R. Bellwied, " P. Braun-Munzinger, W. E. Cleland, G. David J. Dee, O. Dietzsch, S. V. Greene, J. R. Hall, '* T. K. Hemmick, '~ N. Herrmann, '~ B. Hong, K. Jayananda, '~~ D. Kraus, B. S. Kumar, " R. Lacasse, D. Lissauer, W. J. Llope, '~ T. Ludlam, R. Majka, S. K. Mark, S. McCorkle, J. T. Mitchell, M. Muthuswamy, E. O' Brien, C. Pruneau, F. S. Rotondo, ~ U. Sonnadara, J. Stachel, E. M. Takagui, H. Takai, T. G. Throwe, S. Voloshin, "* L. Waters, 'tt C. Winter, D. Wolfe, C. L. Woody, N. Xu, Y. Zhang, Z. Zhang, '~ and C. Zou (E814 Collaboration) Brookhaven NationaL Laboratory, Upton, ¹m York 1i978 McGill University, MontreaL, Canada University of New Mexico, Albuquerque, New Mezico 87181 University of Pittsburgh, Pittsburgh, Pennsylvania 1&60 State University of New York, Stony Brook, New York &&7' Universidade de Sao Paulo, Sao Paulo, Brazil Yale University, ¹u Haven, Connecticut 0651 2 (Received 15 September 1993) We present the results of an analysis of two charged particle and transverse energy correlations in Si+Pb collisions at BNL AGS at 14. 6 GeV/c per nucleon. The measured semi-inclusive normalized two-particle pseudorapidity correlation function exhibits short-range correlations similar to the cor- relations observed in hadron-hadron and hadron-nucleus collisions at higher energies, although the observed correlations are smaller than the values scaled from hp and hA data. Estimates, provided by the observed correlations, of the intermittency indices as well as of the parameters of the cluster model are presented. Predictions using the FRITIQF event generator, which at this level of statistical accuracy show no pseudorapidity correlations, are not in agreement with our data. Azimuthal angle two-particle correlations show nonzero back-to-back correlations in the central region (consistent with FRITIOF predictions) and are almost tlat in the projectile fragmentation region. We also present results on the transverse energy azimuthal correlation function, which are similar to those from the two-particle correlation function. PACS number(s): 13. 20.Jf, 13. 85.Hd I. INTRODUCTION In the past two decades many experiments and theo- retical analyses have been performed which sought un- 'Present address: Dept. of Physics, Wayne State University, Detroit, MI 48202. t Present address: Brookhaven National Laboratory, Upton, NY 11973. ~Present address: Dept. of Physics, State University of New York, Stony Brook, NY 11794. ~Present address: Physikalisches Institut, Universitat Hei- delberg, D 69 Heidelberg, Germany. ~ Present address: Dept. of Physics, University of Sri 3ayewardenepura, Nugegoda, Sri Lanka. ~Present address: Dept. of Physics, Michigan State Univer- sity, East Lansing, MI 48824. On leave &om Moscow Engineering Physics Institute, Moscow, 115409, Russia. ttPresent address: Los Alamos National Laboratory, Los Alamos, NM 87545. derstanding of the dynamics of multiparticle production in high-energy collisions through data on inclusive distri- butions. However, measurements of single-particle dis- tributions alone are insufFicient to understand the details of the production mechanism. The study of correlation effects provides information on hadronic production dy- namics beyond that obtained Rom single-particle spectra and is very important for understanding the role of res- onances, minijets, strings, fn. 'eballs, etc. The correlation function, constructed in a proper way, could be a very sensitive tool for the investigation of special features of models and dynamical assumptions. Particle correlations have been extensively studied in hadron-hadron reactions. When two-particle correlations in rapidity are studied at 6xed charged particle multi- plicity, apparent short-range (Ay 1 — 2) correlations are observed [1 — 8]. The most successful interpretation of this correlation is found in the cluster model [9], although a physical understanding of the nature of clusters is still lacking. The study of two-dimensional correlations in rapidity and azimuthal angle space shows nontrivial az- imuthal angle behavior. At ISR energies [6,7] it was 0556-2813/94/49(3}/1669(15)/$06. 00 1669 1994 The American Physical Society