In previous work [1] we have demonstrated that various observables in the reactions N N ® fN N and pN ® fN show some sensitivity to an admixture of hidden strangeness in the nucleon. It turns out, however, that, within the extended one-boson-exchange model, the effective coupling constants and cut-off parameters are poorly constrained. We have, therefore, continued our analysis to explore the f production mechanism within a conventional one-boson-exchange model by including the recent results of the DISTO collaboration. Our calculated cross sections are displayed in Figs. 1 and 2 together with experimental data.
The data and other constraints of the model parameters are still insufficient to derive a unique set of parameters. Rather there is a wide range of the commonly used cut-off parameter L_frp entering the frp vertex. Some observables, such as the total cross section as a function of the excess energy and the angular distribution, are less sensitive to variations of L_frp. Polarization observables and observables related to the subsequent decays f® e⁺ e^- and f® K⁺ K^- can serve as further constraints to the parameter space.
A detailed understanding of the f production dynamics, in particular the cross sections at small excess energies, is a necessary prerequisite for a profound analysis of the kaon and dilepton channels in heavy-ion collisions.

Fig. 1 The calculated cross sections for the reactions p^- p ® fn (left panel, data from [3]) and p p ® fp p (right panel, data from [4]) as a function of the excess energy above the threshold. Dot-dashed curves: contribution from diagrams with a frp vertex, dashed curves: contributions from diagrams with direct fN N coupling, solid curves: resulting cross sections including interferences. Final state interaction has been included within the Jost function and phase-equivalent potential formalism. For further details see [2].

¹ Bogolyubov Laboratory of Theoretical Physics, JINR Dubna, Russia
² Far-Eastern State University, Vladivostok, Russia

References

[1]  A.I. Titov, B. Kämpfer, V.V. Shkyar, Phys. Rev. C 59 (1999) 999

[2]  A.I. Titov, B. Kämpfer, B.L. Reznik, Eur. Phys. J. A 7 (2000) 543

[3]  A. Baldini et al., Total cross sections of high energy particles, Springer-Verlag, Heidelberg, 1988

[4]  F. Balestra et al. (DISTO Collaboration), Phys. Lett. B 468 (1999) 7  IKH 05/31/01 © B. Kämpfer