Eur. Phys. J. A 14, 247-254 (2002)
DOI: 10.1140/epja/i2001-10195-x
Polarization phenomena by deuteron fragmentation into pions
A.Yu. Illarionov, A.G. Litvinenko and G.I. LykasovJoint Institute for Nuclear Research, 141980 Dubna, Moscow Region, Russia Alexei.Illarionov@jinr.ru
(Received: 17 April 2001 / Revised version: 7 March 2002 Communicated by V. Vento)
Abstract
The fragmentation of deuterons into pions emitted forward in the
kinematic region forbidden for free nucleon-nucleon collisions
is analyzed. The inclusive relativistic invariant spectrum of pions and
the tensor analyzing power
T20 are investigated within the framework
of an impulse approximation using various deuteron wave functions.
The influence of
-wave inclusion in the deuteron wave
function is also studied. The invariant spectrum is shown to be more
sensitive to the amplitude of the
process than the tensor
analyzing power
T20.
It is shown that the inclusion of the non-nucleonic degrees of freedom
in a deuteron results in a satisfactory description of the data
for the inclusive pion spectrum and improves the description of the
data about
T20. According to the data,
T20 has
very small positive values, less than
0.2, which contradicts
the theoretical calculations ignoring these degrees of freedom.
25.10.+s - Nuclear reactions involving few-nucleon systems.
24.70.+s - Polarization phenomena in reactions.
24.10.Jv - Relativistic models.
© Società Italiana di Fisica, Springer-Verlag 2002