Köln 2004 – scientific programme
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HK: Physik der Hadronen und Kerne
HK 38: Electromagnetic and Hadronic Probes VI
HK 38.3: Talk
Thursday, March 11, 2004, 14:30–14:45, B
Close to threshold strangeness production in pp collisions — •Peter Winter — Institut für Kernphysik, Forschungszentrum Jülich
Exclusive data on the pp→ pp K+K− reaction near the production threshold have been taken at the internal experiment COSY-11 [1]. These studies are motivated not only by the possibility to investigate the proton kaon interaction but also by the discussion on the nature of the scalar resonances f0(980) and a0(980). A first total cross section σ=1.80±0.27−0.35+0.28 for the excess energy Q=17 MeV has been determined [2].
In contrary to the η, ω and η′ production, the cross section values obtained at COSY-11 [2] and DISTO [3] are in good agreement with one-meson exchange calculations neglecting final state interaction (FSI) effects [4] as well as with a fit of a four body phase space including the strong pp FSI. Since the strong pp interaction could be compensated by the not well established pK− FSI or due to an additional degree of freedom caused by the four-body final state [4], the investigation of the close to threshold region was extended at the excess energies Q=10 and 17 MeV where strong FSI effects should be more pronounced. The data analysis will be presented and discussed.
[1] S. Brauksiepe et al., Nucl. Instr. & Meth. A 376 (1996) 397.
[2] C. Quentmeier et al., Phys. Lett. B 515 (2001) 276.
[3] F. Balestra et al., Phys. Rev. C 63 (2001) 024004.
[4] A. Sibirtsev, Publ. of Research Centre Jülich: Matter and Materials 11 (2002) 239.