DOI: 10.1140/epja/i2002-10037-5
production in proton-nucleus reactions and the role of
momentum-dependent potentials
Z. Rudy1, W. Cassing2, L. Jarczyk1, B. Kamys1 and P. Kulessa3, 4
1 M. Smoluchowski Institute of Physics, Jagellonian University, PL-30059 Cracow, Poland
2 Institut für Theoretische Physik, Justus Liebig Universität Giessen, D-35392 Giessen, Germany
3 Institut für Kernphysik, Forschungszentrum Jülich, D-52425 Jülich, Germany
4 W. Niewodniczanski Institute of Nuclear Physics, PL-31342, Cracow, Poland
Wolfgang.Cassing@theo.physik.uni-giessen.de
(Received: 28 January 2002 / Published online: 19 November 2002)
Abstract
The production of
K+-mesons in proton-nucleus
collisions from 1.0 to 2.5 GeV is analyzed with respect to
one-step nucleon-nucleon (
) and two-step
-nucleon (
) or
pion-nucleon (
) production channels on
the basis of a coupled-channel transport approach (CBUU)
including the kaon final-state interactions. The influence of
momentum-dependent potentials for the nucleon, hyperon and kaon
in the final state are studied as well as the importance of
K+
elastic rescattering in the target nucleus. The transport
calculations are compared to the experimental
K+ spectra taken
at LBL Berkeley, SATURNE, CELSIUS, GSI and COSY-Jülich. It is
found that the momentum-dependent baryon potentials affect the
excitation function of the
K+ cross-section; at low bombarding
energies of
GeV the attractive baryon potentials in
the final state lead to a relative enhancement of the kaon yield,
whereas the net repulsive potential at bombarding energies
GeV causes a decrease of the
K+ cross-section.
Furthermore, it is pointed out that especially the
K+ spectra
at low momenta (or kinetic energy
TK) allow to determine
the in-medium
K+ potential almost model independently due to a
relative shift of the
K+ spectra in kinetic energy that arises
from the acceleration of the kaons when propagating out of the
nuclear medium to free space,
i.e. converting the potential energy to the kinetic
energy of the free kaon.
13.60.Le - Meson production.
13.75.Jz - Kaon-baryon interactions.
14.40.Aq -
,
K, and
mesons.
25.40.-h - Nucleon-induced reactions.
© Società Italiana di Fisica, Springer-Verlag 2002
