tailieunhanh - Preliminary results on prompt ξ-ξ − production ratio in pp collisions at √ s = 7 tev

The ratio of prompt Ξ +/Ξ − production has been investigated based on a limited data set registered by the LHCb experiment at the CERN Large Hadron Collider in 2010. This ratio has been determined in the rapidity region ≤ y ≤ covered by the LHCb detector. The determination of anti-hyperons to hyperons ratio produced in pp collisions will allow to study the transport of baryons to final state hadrons and to constrain and tune Monte Carlo models. | Communications in Physics, Vol. 22, No. 1 (2012), pp. 83-90 + − PRELIMINARY RESULTS ON PROMPT Ξ √ /Ξ PRODUCTION RATIO IN PP COLLISIONS AT s = 7 TEV NGUYEN THI DUNG Hanoi University of Sciences and Ecole Polytechnique F´ed´erale de Lausanne in 2010-2011 NGUYEN MAU CHUNG Hanoi University of Sciences TRAN MINH TAM Hanoi University of Sciences and Ecole Polytechnique F´ed´erale de Lausanne Abstract. The ratio of prompt Ξ+ /Ξ− production has been investigated based on a limited data set registered by the LHCb experiment at the CERN Large Hadron Collider in 2010. This ratio has been determined in the rapidity region ≤ y ≤ covered by the LHCb detector. The determination of anti-hyperons to hyperons ratio produced in pp collisions will allow to study the transport of baryons to final state hadrons and to constrain and tune Monte Carlo models. I. INTRODUCTION The study of strangeness production is an important ingredient to understand the nature of strong interactions as it can reveal the particle production mechanism in the collision. The introduction of quark-gluon plasma (QGP) could increase production of strange particles. This is because the threshold which is necessary to produce a strange quark is lower in QGP compared with that of a hadron gas. It is expected that this effect may be enhanced for baryons containing several strange quarks. Thus, measurements of hyperon productions or of the ratio of anti-hyperons to hyperons can serve to constrain theories, particularly the transport of baryon number from pp collisions to the final state hadrons, provide input for the tuning of Monte Carlo; at large values of the rapidity, they can be used to probe the fragmentation field and constrain Monte Carlo models. The LHCb experiment offers a unique opportunity to disentangle these effects as it covers the large rapidity region where differences in the fragmentation models reveal themselves as shown in Figure 1 ( [1]). 84 NGUYEN THI DUNG, NGUYEN MAU CHUNG, AND .