Hadron production inpBe interactions at 14.6 GeV/c

Abstract

Abstract. Invariant cross sections for the production of rc • K • p, and d in pBe interactions at 14.6 GeV/c are well reproduced by calculations carried out in the framework of the Rossendorf collision model. PACS: 13.65A systematic set of proton-induced reactions [1] on Be, A1, Cu, and Au targets at 14.6 GeV/c has been measured by the E-802 Collaboration at the BNL-AGS. As pointed out by Abott et al. [1] it is the aim of these experiments to clarify the reaction mechanism of nucleus-nucleus (AA) reactions investigated at the same energy per nucleon [2][3][4].In central SiAu interactions an enhanced K+/Tr + ratio has been observed [3]. This fact is of particular interest, because strangeness production has been discussed in the context of quark-gluon plasma formation [5,6]. So far, theoretical work [7][8][9][10][11][12][13] has mainly concentrated on the explanation of the enhanced K+/Tr + ratio. The comprehensive data set now available is, however, an ideal tool to check models in a more systematic way by considering first pA reactions starting from the lightest systems. After that one can hope to find a more profound explanation of the enhanced K+/Tr + ratio. In the present note a first step is done by calculating the invariant cross sections for the production of 7r ~, K § p, and d in pBe interactions within the framework of the Rossendorf collision (ROC) model [14, 15, and references therein]. First results for K production in the rapidity interval 1.2 < y < 1.4 from pBe and pAu reactions has been discussed in [16].The ROC model does not need parametrizations of elementary hadronic interactions as input for the interpretation of nuclear reactions, because it aims at a simultaneous description of both hadronic and nuclear reactions. Thus, a consistent treatment in the framework of the ROC model includes the consideration of particle production in hadronic processes. It has been demonstrated in another context [17] that the main features of particle production in pp interac- In the ROC model a nuclear reaction is described on the basis of the participant-spectator picture. Each interaction of the incident proton with the target nucleus (AZ) consisting of A nucleons and Z protons is characterized by the number a of target nucleons and z of target protons involved in the reaction. The cross sections cruz for the interaction of the projectile with (az) target nucleons are calculated on the basis of a probabilistic interpretation of the Glauber theory [ 19]. A multi-step picture is proposed to describe the interaction process, where a group of (az) participating target nucleons is treated as a single entity called cluster. In the first step translational energy is converted into internal excitation energy of subsystems emerging from the proton-cluster interaction and of the residual nucleus containing A -a nucleons and Z -z protons.The excited subsystems contain the valence quarks of the participants and additional quark-antiquark pairs created during the collision. In the second stage of the reaction all quarks re...