Speaker
Dr
Valery Lyuboshitz
(Joint Institute for Nuclear Research, Dubna)
Description
The structure of the nucleon charge-exchange process $n + p \rightarrow p + n$ is theoretically investigated on the basis of the isotopic invariance of the nucleon-nucleon scattering. By using the operator of permutation of the spin projections of the neutron and proton, the connection between the spin
matrices, which describe the amplitude of the "forward" nucleon charge-exchange process and the amplitude of the neutron-proton elastic scattering
in the "backward" direction, has been obtained. Due to the optical theorem, the spin-independent part of the differential cross-section of the process $n + p \rightarrow p + n$ at zero angle for unpolarized particles is expressed through the difference of total cross-sections of
unpolarized proton-proton and neutron-proton scattering. Meantime, the spin-dependent part of this cross-section is
proportional to the differential cross-section of the "forward" deuteron
charge-exchange breakup $d + p \rightarrow (pp) + n$ at the deuteron
momentum ${\bf k}_d = 2 {\bf k}_n$ (${\bf k}_n$ is the initial neutron momentum). As shown by the performed analysis, it is just the spin-dependent term that provides the main contribution into the differential cross-section of the "forward" process $n + p \rightarrow
p + n$ in the wide range of neutron laboratory momenta $k_n > 700$ $MeV/c$ .
Author
Dr
Valery Lyuboshitz
(Joint Institute for Nuclear Research, Dubna)
Co-author
Dr
Vladimir Lyuboshitz
(Joint Institute for Nuclear Research, Dubna)
