12 research outputs found
Eta and eta-prime meson production in the reaction pn -> dM near threshold
The two-step model with pi-, rho- and omega- exchanges taken into account is
applied to investigate the reactions pn -> d eta and pn -> d eta-prime. The
existing experimental data on the reaction pn -> d eta are analysed and
predictions for the cross section of the reaction pn -> d eta-prime are
presented. It is found that pi- as well as rho exchange yield significant
contributions in both reactions. The effect of the final state interaction is
also studied.Comment: 15 pages, 4 figure
Incoherent Photoproduction of -mesons from the Deuteron near Threshold
Incoherent photoproduction of the -meson on the deuteron is studied for
photon energies from threshold to 800 MeV. The dominant contribution, the
N-N amplitude, is described within an isobar model. The final
state interaction derived from the CD-Bonn potential is included and found to
be important for the description of the production cross section close to
threshold. Possible effects from the final state interaction are
discussed.Comment: 11 pages, revtex, including 6 figure
Eta Meson Production in NN Collisions
Eta meson production in both proton-proton and proton-neutron collisions is
investigated within a relativistic meson exchange model of hadronic
interactions. It is found that the available cross section data can be
described equally well by either the vector or pseudoscalar meson exchange
mechanism for exciting the S_{11}(1535) resonance. It is shown that the
analyzing power data can potentially be very useful in distinguishing these two
scenarios for the excitaion of the S_{11}(1535) resonance.Comment: Revtex, 35 pages, 8 figure
Near-threshold and meson productions in collisions
Using a relativistic effective Lagrangian at the hadronic level,
near-threshold and meson productions in proton proton ()
collisions, , are studied within the distorted wave
Born approximation. Both initial and final state interactions are
included. In addition to total cross section data, both and
angular distribution data are used to constrain further the model parameters.
For the reaction we consider two different possibilities:
with and without the inclusion of nucleon resonances. The nucleon resonances
are included in a way to be consistent with the
reaction. It is shown that the inclusion of nucleon resonances can describe the
data better overall than without their inclusion. However, the SATURNE data in
the range of excess energies MeV are still underestimated by about a
factor of two. As for the reaction it is found that the
presently limited available data from DISTO can be reproduced by four sets of
values for the vector and tensor coupling constants. Further
measurements of the energy dependence of the total cross section near threshold
energies should help to constrain better the coupling constant.Comment: Latex, 37 pages, 13 figures (14 EPS-figure files), text modified,
version to appear in Phys. ReV.
K− 3He and K− 4He interactions at low energies
Using the multiple scattering approach (MSA) in the fixed center approximation we calculated the K− 4He and K− 3He scattering lengths. The K− 4He scattering length is also analyzed in the optical potential model. Within the MSA the K− 3He final state interaction factor was also calculated. It is found that the K− 3He mass spectrum for the pd → 3HeK+ K− reaction is expected to be influenced by the K− 3He FSI effect