Speaker
Dr
Valery Lyuboshitz
(Joint Institute for Nuclear Research, Dubna, Russia)
Description
The structure of the nucleon charge-exchange process
n + p --> p + n is investigated basing on the isotopic
invariance of the nucleon-nucleon scattering. Using the operator
of permutation of the spin projections of the neutron and proton,
the connection between the spin matrices, describing the amplitude
of the nucleon charge-exchange process at zero angle and the
amplitude of neutron elastic scattering on the proton
in the "backward" direction, has been considered. Due to the
optical theorem, the spin-independent part of the differential
cross-section of the process n + p --> 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 deuteron charge-exchange breakup
d + p --> (pp) + n at zero angle at the deuteron
momentum {\bf k}_d = 2{\bf k}_n ( {\bf k}_n is the initial
neutron momentum ). Analysis shows that, assuming the real part
of the spin-independent term of the "forward" amplitude of the
process n + p --> p + n to be smaller or of the same
order as compared with the imaginary part, in the wide range of
neutron laboratory momenta k_n > 700 MeV/c the main contribution
into the differential cross-section of the process n + p --> p + n
at zero angle is provided namely by the spin-dependent term .
Author
Dr
Valery Lyuboshitz
(Joint Institute for Nuclear Research, Dubna, Russia)
Co-author
Dr
Vladimir Lyuboshitz
(Joint Institute for Nuclear Research, Dubna, Russia)
