DOI: 10.1140/epja/i2002-10140-7
Final-state interaction in semi-inclusive DIS off nuclei
C. Ciofi degli Atti1 and B.Z. Kopeliovich2, 31 Department of Physics, University of Perugia, and INFN, Sezione di Perugia, via A. Pascoli, Perugia, I-06100, Italy
2 Max-Planck-Institut für Kernphysik, Postfach 103980, 69029 Heidelberg, Germany
3 Institut für Theoretische Physik der Universität, 93040 Regensburg, Germany
ciofi@pg.infn.it
bzk@pluto.mpi-hd.mpg.de
(Received: 28 June 2002 / Revised version: 6 October 2002 / Published online: 5 May 2003)
Abstract
The Final-State Interaction (FSI) in Deep-Inelastic Scattering (DIS) of
leptons off a nucleus
A, due to the propagation of the struck nucleon
debris and its hadronization in the nuclear environment is considered.
The effective cross-section of such a partonic system with the nucleons
of the medium and its time dependence are estimated, for different values
of the Bjorken scaling variable, on the basis of a model which takes into
account both the production of hadrons due to the breaking of the color
string, which is formed after a quark is knocked out off a bound nucleon,
as well as the production of hadrons originating from gluon radiation. It
is shown that the interaction, the evolution and the hadronization of the
partonic system in the nuclear environment can be thoroughly investigated
by a new type of semi-inclusive process, denoted
A(e,e'(A-1))X, in
which the scattered lepton is detected in coincidence with a heavy
nuclear fragment, namely a nucleus (
A-1) in low energy and momentum
states. As a matter of fact, if the FSI is disregarded, the momentum
distribution of (
A-1) is directly related to the momentum distribution of
the nucleon before
absorption, i.e. the same quantity which
appears in the conventional
A(e,e'N)X process, where
N denotes a
nucleon. The rescattering of the struck nucleon debris with the medium
damps and distorts the momentum distributions of (
A-1) in a way which is
very sensitive to the details of the effective cross-section of the debris
with the nucleons of the medium. The total cross-section of the process
A(e,e'(A-1))X on
,
, and
, related to the
probability that after a target nucleon experiences a DIS process, the
recoiling (
A-1) nucleus remains intact in spite of the strong FSI, is
evaluated, and the distorted momentum distribution of the recoiling (
A-1)
system is obtained. It is shown that both quantities are very sensitive
to the details of the early stage of hadronization of the nucleon debris
in the nuclear medium.
24.85.+p - Quarks, gluons, and QCD in nuclei and nuclear processes.
25.10.+s - Nuclear reactions involving few-nucleon systems.
25.30.Dh - Inelastic electron scattering to specific states.
25.30.Fj - Inelastic electron scattering to continuum.
© Società Italiana di Fisica, Springer-Verlag 2003
