On Parity Violation in Compound Nuclei

Formal theory of neutron induced fission

“…Thus no interference terms should contribute to the inclusive differential fission cross section. However, such terms were experimentally observed as P-odd [13] and P-even [14,15] angular correlations in neutron induced fission. The first one is caused by the interference of diverging waves with orbital momenta L and L of opposite parities.…”

“…Here µ α is a reduced mass, r α is a relative radius-vector, directed from particle 1 (heavy) to particle 2 (light), Z αi is a charge of i-th particle in units of elementary charge e, andĤ αi is a hamiltonian of internal motion of i-th particle. We take the functions (u (∓) αl /r α )ϕ cα λα as a complete set of eigenfunctions of hamiltonian (13). Radial functions u (−) αl (r α ) and u (+) αl (r α ) = (u (−) αl (r α )) * are solutions of equation…”

“…Outside an area of nuclear interaction a total wave function is a superposition of eigenfunctions of hamiltonians (13). Taking into account, that the converging waves exist only in an entrance channel, we write…”

“…We mean, first, parity-nonconserving (P-odd) correlation of fission axis and spin of captured neutron [13], and, second, P-even "left-right" [14] and "forward-backward" [15] correlations. Sushkov and Flambaum [16] extended the A. Bohr's approach to such effects.…”

Parity nonconservation and Brosa modes in nuclear fission

“…Danilyan et al many years ago [1]. Studying angular distributions of fission fragments in reactions induced by thermal polarized neutrons, an asymmetry of fragment emission relative to the spin direction of the incoming neutron and hence the direction of polarization of the capture compound state was observed.…”