Charge Exchange Part of the Effective Two-Body Interaction

Heavy ion charge exchange reactions as probes for nuclearβ-decay

“…If properly separated in the measurements, the relative yields observed for this doublet ( 3 2 − g.s. and 1 2 − excited state) can be directly connected to the ratio of spin-flip to non-spin-flip interaction [100][101][102][103]. Thereby important information on the spin structure of the isovector nucleon-nucleon interaction is obtained.…”

Nucleon Charge-Exchange Reactions at Intermediate Energy

“…The relation above seems to have first been written explicitly in [21], but the ideas behind it were assumed, if not explicitly stated, in all the prior studies of interest here. In these, the most clear-cut conclusions were obtained from studies of the (p,n) reaction on the J π = 0 + , T = 1 targets 14 C [17] and 18 O [16].…”

“…During the following decade a number of studies investigated the properties of the isovector effective interaction utilizing the correspondence between betadecay matrix elements and those for the (p, n) reaction cross section [ 16,17,18,19,20,21]. It was recognized that the momentum transfer in beta decay was small, so that the transition amplitude for the (p,n) reaction should also be evaluated for q 0, i.e., near scattering angle θ = 0.…”

Ratio of the Isovector Spin-Flip to Nonflip Effective Interaction from 0 (p, n) Scattering

“…Our formulation is analogous to that of the nonrelativistic approach.7) The starting point is the relativistic distorted-wave impulse approximation (RDWIA)16) to the transition matrix for (p, n) scattering: (1) where the relativistic distorted-wave function cj J of the incident proton (denoted by 0) or the outgoing neutron, with momentum h or h' and spin projection s or s', is calculated by the relativistic optical modeP7) and lJT(jM) is the nuclear wave function with spin] and its projection M.…”

“…The free NN t-matrix operator tOj is given by the usual five Fermi covariants :18) (2) with (3) The operator yO(O) y0(j) tOj in (1) is represented by the familiar form in .a-decay theory:16) Furthermore, we treat the wave function of the target nucleon nonrelativistically. Namely, its lower component is neglected and the upper component is regarded as the nonrelativistic wave function, so that n(j)-::::=.n(j)-::::=.…”