Verlag des Forschungszentrums Jülich
JUEL-4017
The close to threshold η' production in proton-proton collisions has already
been investigated at the COSY-11 facility. Cross section values in the threshold
region have been measured . However, until now no data have been taken for the
η' meson production in the proton-neutron collision .
In order to investigate the η' production in proton-neutron collisions at the
COSY synchrotron, the COSY-11 facility has been equipped with two new subsystems,
namely the neutron detector and the spectator counter. The optimization
of the topography for these additional detectors, the selection of the most suitable
beam momentum and a discussion for the method of luminosity determination for
the quasi-free pn→pnn(η') reactions are presented in this thesis. Rates for the
production of η and η' mesons in proton-neutron collisions at COSY-11 have been
estimated . For the calculations a special fast program has been written.
Czyzykiewicz, Rafal
n and n meson production in the quasi-free proton-neutron collisions at the COSY-11 facility
78 S., 2003
Both, the structure of the η' meson as well as its production mechanism are
still under strong discussion and debate. The most possible hypothesis concerning
the explanation of the almost three times larger mass for this meson observed
experimentally relative to the theoretically calculated mass is a gluonium admixture
to the η' wave function . This gluonium admixture should reflect itself in the
production yield of the η' meson in proton-neutron collisions . Since the production
of η' meson through the gluonium exchange is isospin independent, the ratio
Rη, = o(pn→pnn)/o(pp→ppn)
close to threshold is expected to be Rη = 1, after corrections for initial and final state interactions .
Neuerscheinungen
Schriften des Forschungszentrums Jülich
Ihre Ansprechperson
Heike Lexis
+49 2461 61-5367
zb-publikation@fz-juelich.de