Production of multi-strange hyperons and strange resonances inthe NA49 experiment

R A Barton ,S Margetis ,R Bramm ,M Botje ,P Csató ,H Białkowska ,A M Poskanzer ,C O Blyth ,J Molnár ,Z Fodor ,M Toy ,V Eckardt ,H G Fischer ,T Sammer ,F Siklér ,T Kollegger ,M Pikna ,H Sann ,A Malakhov ,D Weerasundara ,E Gładysz ,V Friese ,L Pinsky ,J M Nelson ,T A Yates ,P Jacobs ,S Wenig ,C Blume ,T Šuša ,G.t.a Squier ,I Szarka ,N Schmitz ,R Janik ,P Freund ,A Sandoval ,J Ftáčnik ,János Gál ,G Pálla ,R Brun ,D Cebra ,M Ivanov ,B Mayes ,P Strmeň ,M Vassiliou ,H Ströbele ,I Szentpétery ,J Bächler ,A Billmeier ,L Betev ,P G Jones ,J Braciník ,C Roland ,D Ferenc ,S Trentalange ,Raimond Snellings ,D Prindle ,G Igo ,D Varga ,K Kadija ,A Wetzler ,S A Voloshin ,A Rybicki ,A Mischke ,G E Cooper ,G Odyniec ,R Renfordt ,C Markert ,G L Melkumov ,M Van Leeuwen ,D Barna ,P Lévai ,J Sziklai ,B Boimska ,F Pühlhofer ,I K Yoo ,L S Barnby ,G Roland ,C Whitten ,P Bunčić ,D Röhrich ,T Antičić ,P Filip ,P Seyboth ,J G Reid ,F Wang ,V Kolesnikov ,T A Trainor ,V Hlinka ,A Petridis ,P Foka ,S Hegyi ,H G Ritter ,N Xu ,M Kowalski ,S Afanasiev ,G Vesztergombi ,D Vranić ,F.p Brady ,J Bartke ,G I Veres ,B Sitár ,F Eckhardt ,G Georgopoulos ,Erich Schäfer ,C Höhne ,J G Cramer ,W Retyk ,Lincoln D Carr ,E Skrzypczak ,A Panagiotou ,M Gaździcki ,R Stock ,J Zimányi

doi:10.1088/0954-3899/27/3/314

Abstract

The NA49 large-acceptance hadron spectrometer has measured strange andmulti-strange hadrons from Pb + Pb and p + p collisions at the CERN SPS.Preliminary results for the transverse mass and rapidity distributions forΞ- and from central Pb + Pb collisions at158 GeV c-1/nucleon are presented. Fully integrated yields per event of 4.42 ± 0.31 and 0.74 ± 0.04 are found for Ξ- and, respectively, leading to a 4π /Ξ- ratio of 0.17 ± 0.02. The ratio /Ξ-at mid-rapidity is found to be 0.22 ± 0.04, agreeing with previouslypublished values. In addition, preliminary data on the Λ(1520)and ϕ (1020)resonances are presented. The Λ(1520) multiplicity for p + pcollisions is found to be 0.012 ± 0.003. No signal is observed for Pb +Pb collisions and a production upper limit of 1.36 Λ(1520) perevent indicates an apparent suppression when comparing with scaled p + p data. Integrated ϕ(1020) yields perevent are found to be 7.6 ± 1.1 for Pb + Pb and 0.012 ± 0.0015for p + p collisions. No significant shift or broadening of the ϕ(1020)invariant mass distribution is observed in central Pb + Pb collisions.

Full Text