Pickup coupling effects in deuteron scattering: The case ofd+Ca40

Abstract

The dynamic polarization potential (DPP) contribution to the effective deuteron-nucleus interaction is evaluated by means of coupled reaction channel (CRC) calculations followed by S-matrix-to-potential inversion. The full coupled channel S matrix S J l l is inverted using the iterative-perturbative algorithm to yield a potential that includes a complex T R tensor term as well as central and spin-orbit components. The differences between the various components of the inverted potential and the corresponding terms in the bare potential of the CRC calculation constitute a local equivalent representation of the complete DPP that is generated by the reaction channel coupling. The magnitude of the DPP, the real part in particular, is much less than that found in earlier calculations in which the nonorthogonality terms were omitted. The characteristic features of the tensor part of the DPP were traced to breakup and reorientation processes in the entrance deuteron channel that had been included with the pickup. The contribution of stripping to the deuteron-nucleus interaction is also discussed.

Theory of (d,p) and (p,d) reactions including breakup: Comparison of methods

“…There have been a few applications of CDCC to transfer reactions (e.g., Refs. [5,[22][23][24][25][26]), and results demonstrate the variety of phenomena that can be addressed within this same framework. While new developments of the CDCC method are taking place [27][28][29], here we would like to focus on a better understanding of the transfer matrix element when breakup is included.…”

Reaction channel contributions to the helion optical potential

“…In the present work we study the contribution to the 3 He OMP of coupling to transfer channels and collective excitations. The contribution of coupled reaction channels to the OMP was studied for protons (for recent contributions see [4][5][6][7][8]) and deuterons [9], but in both these cases many effects were omitted or treated incompletely. For example, in the case of the contribution of neutron pickup to proton scattering, the breakup of the deuteron was not taken into account in most cases.…”

Coupling effects in proton scattering from40Ca

“…Apart from one calculation, the calculations that did include all the 5/2 + strength lumped these nine states into three states at 5.6175, 7.3148 and 8.5148 MeV, having the same aggregate pickup strength. The choice of states in 39 Ca was as in our previous reanalysis [13] of the 40 Ca(d, t) data of Doll et al [14], where we omitted states with spectroscopic factors C 2 S < 0.2 in order to keep the number of states within tractable limits while retaining the main coupling strength.…”

“…of 39 Ca is increased to the value expected for a state that is a pure 3/2 + hole state. In the unmodified case "3/2 + ," the SF was taken from our reanalysis [13] of the 40 Ca(d,t) 39 Ca pickup data of Doll et al [14]; this was then increased to the sum-rule value, giving a 1.674-fold increase in the spectroscopic factor. The volume integrals of the various components of the DPP increase by factors that are systematically greater than 1.674, markedly so for the spinorbit components.…”