Proton–neutron asymmetry independence of reduced single-particle strengths derived from (p,d) reactions

Abstract

An overall reduction factor (ORF) is introduced for studying the quenching of single particle strengths through nucleon transfer reactions. The ORF includes contributions of all the probed bound states of the residual nucleus in a transfer reaction and permits a proper comparison with results of inclusive knockout reactions. A systematic analysis is made with 103 sets of angular distribution data of (p, d) reactions on 21 even-even targets with atomic mass numbers from 8 to 56 using the consistent three-body model reaction methodology proposed in [J. Lee, J.A. Tostevin, B.A. Brown, et al., Phys. Rev. C 73, 044608 (2006)]. The extracted ORFs are found to be nearly independent on the nuclear isospin asymmetry, which is different from the systematics of inclusive knockout reactions but is consistent with the recent measurement of (d, t), (d, 3 He), (p, 2p), and (p, pn) reactions on nitrogen and oxygen isotopes and ab initio calculations.

Breakup reactions and their ambiguities

“…While for the removal of a deeply bound nucleon, the model overestimates the experimental cross section by a factor 3-5, which has been first interpreted as a possible indication of missing correlations for deeply-bound nucleons in shell model calculations [50]. On the other hand, only a weak or even no dependence on proton-neutron asymmetry has been observed in transfer reactions [52][53][54][55]. Although the conclusions are based on few experimental data, still this apparent inconsistent dependence of SFs on proton-neutron asymmetry calls for a deeper understanding on the reaction mechanism and correlations in nuclei.…”

Ambiguities from Nuclear Interactions in the \(^{12}\)C(p,2p)\(^{11}\)B Reaction

“…This allows us to include in our comparison the neutron SFs from two systematic (p, d) reactions analyses of Refs. [68,69]. The mean values of the g.s.…”

“…The mean values of the g.s. SFs from transfer reactions [68][69][70] are larger than those of (p, 2p) at 392 MeV and (e, e p) by approximately 22%. However, we note that within the total uncertainty, the g.s.…”

Quenching of single-particle strengths of carbon isotopes 9-12,14-20C with knockout reactions for incident energies 43–2100 MeV/nucleon *

“…The quenching of single-particle strength (SPS) is an important topic in nuclear physics (see review [7]). Transfer [8][9][10][11][12][13][14][15], single-nucleon removal [16][17][18][19][20][21][22][23][24], and quasi-free knockout [25][26][27][28][29] reactions are common probes for the quenching of SPS across a wide region of proton-neutron asymmetry , which is defined as the difference between the neutron and proton separation energies of the particles concerned, i.e., for neutron removal and for proton removal. Experiments using different reactions and/or beam energies are expected to extract consistent nuclear structure information for any nuclei.…”