TITLE:
Space-Time Description of Cross Sections and Durations of Neutron-Nucleus Scattering near 1 - 2 Resonances in the C- and L-Systems
AUTHORS:
V. S. Olkhovsky
KEYWORDS:
Space-Time Approach to Nuclear Collision, Time Delay, Time Advance, Transformations of Cross Sections from the C-System to the L-System, Interference Phenomena
JOURNAL NAME:
Open Access Library Journal,
Vol.2 No.7,
July
20,
2015
ABSTRACT:
The appearance of time advance (due to distortion by the non-resonant
background) instead of the expected time delay in the region of a
compound-nucleus resonance in the center-of-mass (C-) system is known. Here at
the same conditions we study cross sections and durations of the neutron-nucleus
scattering in the laboratory (L-) system. Here there are a review of papers
where it is shown that such time advance is a virtual paradox and in the
L-system the time-advance phenomenon does not occur and only the trivial time
delay is observed. At the same time the transformations from C-system into the
L-system appear to be different from the standard kinematical transformations
because in the C-system the motion of a compound nucleus is absent but it is
present in the L-system. Here we analyze the initial wave-packet motion (after
the collision origin) and the cross section in the laboratory (L-) system. Also
here (as physical revelations of profound general methodic and in very good
consistent accordance with the experiment) several results of the calculated
cross sections for the neutron-nucleus in comparison with the experimental data
in the L-system at the range of one or two
overlapped compound resonances are presented. It is shown in the
space-time approach that the standard cinematic transformations of cross
sections from the C-system to the L-system are not valid because it is
necessary to consider the center-of-mass motion in the L-system. Finally on a
correct self-consistent base of the space-time description of the nuclear processes
in the laboratory system with 3 particles in the final channel, the validity of
the former approach is shown, which is obtained for the space-time description
of the nuclear processes with 2-particle channels earlier.