Eur. Phys. J. A 11, 237-245 (2001)
Medium effects in the production and
decay of
-mesons in pA collisions in the GeV region
Ye.S. Golubeva1, L.A. Kondratyuk2, M. Büscher3, W. Cassing4, V. Hejny3 and H. Ströher3
1 Institute of Nuclear Research, 117312 Moscow, Russia
2 Institute of Theoretical and Experimental Physics, 117259 Moscow, Russia
3 Forschungszentrum Jülich, Institut für Kernphysik, 52425 Jülich, Germany
4 Institute for Theoretical Physics, University of Giessen, D-35392 Giessen, Germany
m.buescher@fz-juelich.de
(Received: 2 April 2001 / Revised version: 23 May 2001 Communicated by A. Schäfer)
Abstract
The resonance production and its
decay in
pA reactions close to threshold is considered within the
Intranuclear Cascade (INC) model. The
invariant-mass distribution shows two components which correspond
to the
decay "inside" and "outside" the nucleus, respectively.
The "inside" component is distorted by medium effects, which
introduce a mass shift as well as collisional broadening for the
-meson and its decaying pion. The relative contribution of
the "inside" component is analyzed in detail for different
kinematical conditions and nuclear targets. It is demonstrated
that a measurement of the correlation in azimuthal angle between
the
and
momenta allows to separate events related
to the "inside"
decay from different sources of
background when uncorrelated
's and
's are
produced.
25.40.Ep - Inelastic proton scattering.
25.80.-e - Meson- and hyperon-induced reactions.
25.80.Ek - Pion inelastic scattering.
© Società Italiana di Fisica, Springer-Verlag 2001