Nucleon charge exchange on the deuteron: A critical review

Abstract

The existing experimental data on the d(n, p)nn and d(p, n)pp cross sections in the forward direction are reviewed in terms of the Dean sum rule. It is shown that the measurement of the ratio of the charge exchange on the deuteron to that on the proton might, if taken together with other experimental data, allow a direct construction of the np → np scattering amplitude in the backward direction with few ambiguities. PACS. 13.75.Cs Nucleon nucleon interactions -25.40.Kv Charge-exchange reactions -25.10.+s Nuclear reactions involving few-nucleon systems 1 See Ref. [8] for a very comprehensive discussion of different amplitude bases.

Review of quasi-elastic charge-exchange data in the nucleon-deuteron breakup reaction

“…More crucially, the spin information from the ( n, p ) or ( d, {pp}) reactions enables one to separate the different spin contributions to the small angle charge exchange cross section. It could of course be argued that this is not just a benefit for an exclusive reaction since, if the Dubna bubble chamber experiments [47] had been carried out with a polarised deuteron beam, then these would also have been able to separate the contributions from the two independent forward spin-spin contributions through the use of the generalised Dean sum rule [13,10]. It is, however, much more feasible to carry out (d, {pp}) measurements with modern electronic equipment and the hope is that, through the use of polarised beams and targets, they will lead to evaluations of the relative phases between the three independent np → pn spin-spin amplitudes out to at least q ≈ m π [90].…”

“…Since we have recently reviewed the phenomenology of the d(n, p) and d(p, n) charge exchange [10], the theory will not be treated here in any detail. The aim of the present paper is rather to discuss the database of the existing inclusive and exclusive measurements and make comparisons with the information that is available from neutron-proton elastic scattering data.…”

Recent results from the deuteron charge–exchange on hydrogen programme at ANKE/COSY

“…It was emphasised many years ago that quasi-free (p, n) or (n, p) reactions on the deuteron can act, in suitable kinematic regions, as a spin filter that selects the spin-dependent contribution to the np elastic cross section [2]. The comparison of this reaction with free backward elastic scattering on a nucleon target might allow a direct reconstruction of the np backward amplitudes [3].…”

Spin physics experiments at NICA-SPD with polarized proton and deuteron beams

“…The reaction dp → (pp) S n at low momentum transfer from the incident deuteron to the final di-proton (pp) S allows to measure a spin-flip part of the nucleon-nucleon charge-exchange amplitudes [44,45]. Selecting two final protons with low energy, typically E pp < 3 MeV, one can have the emerging di-proton (pp) S dominantly in the 1 S 0 state.…”