https://doi.org/10.1140/epja/i2003-10236-6
Energy dependence of the Λ/Σproduction cross-section ratio in p-p interactions
1
Institut für Kernphysik, Forschungszentrum Jülich, D-52425, Jülich, Germany
2
Institut für Kernphysik, Westfälische Wilhelms-Universität, D-48149, Münster, Germany
3
Institute of Nuclear Physics, PL-31 342, Cracow, Poland
4
Institute of Physics, Jagellonian University, PL-30 059, Cracow, Poland
5
Institute of Physics, University of Silesia, PL-40 007, Katowice, Poland
6
Zentrallabor für Elektronik, Forschungszentrum Jülich, D-52425, Jülich, Germany
* e-mail: p.kowina@fz-juelich.de
Received:
21
July
2003
Accepted:
28
May
2004
Published online:
3
November
2004
The production of the Λ- and Σ0-hyperons has been measured via the pp → pK +Λ/Σ0 reaction at the internal COSY-11 facility in the excess energy range between 14 and 60 MeV. The transition of the Λ/Σ0 cross-section ratio from about 28 at Q≤13 MeV to the high-energy level of about 2.5 is covered by the data showing a strong decrease of the ratio between 10 and 20 MeV excess energy. Effects from the final-state interactions in the p-Σ0 channel seem to be much smaller than in the p-Λ channel. Estimates of the effective range parameters are given for the NΛ and the NΣ systems.
© Società Italiana di Fisica and Springer-Verlag, 2004