Production of Lambda and Sigma^0 hyperons in proton-proton collisions
Abstract
This paper reports results on simultaneous measurements of the reaction channels pp -> pK+\Lambda and pp -> pK+\Sigma^0 at excess energies of 204, 239, and 284 MeV (\Lambda) and 127, 162, and 207 MeV (\Sigma^0). Total and differential cross sections are given for both reactions. It is concluded from the measured total cross sections that the high energy limit of the cross section ratio is almost reached at an excess energy of only about 200 MeV. From the differential distributions observed in the overall CMS as well as in the Jackson and helicity frames, a significant contribution of interfering nucleon resonances to the \Lambda production mechanism is concluded while resonant \Sigma^0-production seems to be of lesser importance and takes place only through specific partial waves of the entrance channel. The data also indicate that kaon exchange plays a minor role in the case of \Lambda- but an important role for \Sigma^0-production. Thus the peculiar energy dependence of the \Lambda-to-\Sigma^0 cross section ratio appears in a new light as its explanation requires more than mere differences between the p\Lambda and the p\Sigma^0 final state interaction. The data provide a benchmark for theoretical models already available or yet to come.
Keywords
Cite
@article{arxiv.1008.4287,
title = {Production of Lambda and Sigma^0 hyperons in proton-proton collisions},
author = {TOF Collaboration and M. Abdel-Bary and S. Abdel-Samad and K-Th. Brinkmann and H. Clement and J. Dietrich and E. Doroshkevich and S. Dshemuchadse and K. Ehrhardt and A. Erhardt and W. Eyrich and D. Filges and A. Filippi and H. Freiesleben and M. Fritsch and W. Gast and J. Georgi and A. Gillitzer and J. Gottwald and D. Hesselbarth and H. Jäger and B. Jakob and R. Jäkel and L. Karsch and K. Kilian and H. Koch and M. Krapp and J. Kreß and E. Kuhlmann and A. Lehmann and S. Marcello and S. Marwinski and S. Mauro and W. Meyer and P. Michel and K. Möller and H. P. Morsch and H. Mörtel and L. Naumann and N. Paul and L. Pinna and C. Pizzolotto and Ch. Plettner and S. Reimann and M. Richter and J. Ritman and E. Roderburg and A. Schamlott and P. Schönmeier and W. Schroeder and M. Schulte-Wissermann and T. Sefzick and F. Stinzig and M. Steinke and G. Y. Sun and A. Teufel and W. Ullrich and G. J. Wagner and M. Wagner and R. Wenzel and A. Wilms and P. Wintz and S. Wirth and P. Wüstner and P. Zupranski},
journal= {arXiv preprint arXiv:1008.4287},
year = {2012}
}
Comments
18 pages, 10 figures; accepted by The European Physical Journal A (EPJ A)