2020 Impact factor 3.043
Hadrons and Nuclei
Eur. Phys. J. A 17, 145-152 (2003)
DOI: 10.1140/epja/i2001-10272-2

Subthreshold $\mth{K^-}$-meson production in proton-nucleus reactions revisited

E.Ya. Paryev

Institute for Nuclear Research, Russian Academy of Sciences, Moscow 117312, Russia

Paryev@a120.INR.Troitsk.ru

(Received: 26 July 2001 / Revised version: 23 December 2002 / Published online: 8 April 2003)

Abstract
We study the inclusive K--meson production in proton-nucleus collisions in the subthreshold energy regime in the framework of a spectral function approach for incoherent primary proton-nucleon and secondary pion-nucleon production processes. Our approach takes properly into account the effect of the nuclear mean-field potentials on these processes, as well as the final-state interaction (FSI) among the outgoing nucleons participating in the one-step antikaon creation process. A detailed comparison of the model calculations of the K- differential cross-sections for the reactions $p\,+$ $\chem{^{9}Be}$, $p\,+$ $\chem{^{63}Cu}$, and $p\,+$ $\chem{^{197}Au}$ at subthreshold energies with the currently available experimental data obtained recently at the ITEP proton synchrotron and at SIS/GSI is given. We find that our calculation, which includes both the nuclear density-dependent mean-field potentials and the elementary NN-FSI effects on the K- production from the direct mechanism, is able to reproduce the energy dependences of the invariant differential cross-sections for the "hard" antikaon creation in p- $\chem{^{9}Be}$ and p- $\chem{^{63}Cu}$ collisions. This result contradicts previous estimates which used only density-dependent mean fields in calculating the K- yield from this mechanism. We further show that the NN-FSI effects play a minor role in describing the data on the spectrum of the relatively soft K--mesons from p- $\chem{^{197}Au}$ interactions at incident energy of $2.5~{\rm GeV}$. We find that the relative strength of the proton- and pion-induced reaction channels in the subthreshold energy regime is governed by the kinematics of the experiment under consideration. We also explore the influence of the antikaon mean-field potential on the K- yield at low antikaon momenta.

PACS
25.40.-h - Nucleon-induced reactions.

© Società Italiana di Fisica, Springer-Verlag 2003