DOI 10.1007/s100520000362
The components of the
cross
section
E. Gotsman - E. Levin - U. Maor - E. Naftali
School of Physics and Astronomy,
Raymond and Beverly Sackler Faculty of Exact Science,
Tel Aviv University,
Tel Aviv, 69978, Israel
Received: 12 January 2000 / Published online: 6 April 2000 - © Springer-Verlag 2000
Abstract
We extend our previous treatment
of
the
p cross section based on Gribov's hypothesis
to the
case of
photon-photon scattering. With the aid of two parameters, determined
from
the experimental data, we separate the interactions into two
categories
corresponding to short ("soft'') and long ("hard'') distance
processes.
The
photon-photon cross section thus receives contributions from
three sectors,
soft-soft, hard-hard and hard-soft. The additive quark model
is used to
describe the soft-soft sector, pQCD the hard-hard sector, while
the hard-soft
sector is determined by relating it to the
system.
We calculate
and display the behaviour of the total photon-photon cross section
and its
various components and polarizations for different values of
energy and
virtuality of the two photons, and discuss the significance of
our results.
Copyright Società Italiana di Fisica, Springer-Verlag 2000
