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

Abstract

To study the quenching of single-particle strengths of carbon isotopes, a systematic analysis is made for 9−12,14−20C, with single neutron knockout reactions on Be/C targets, within an energy range from around 43 to 2100 MeV/nucleon, using the Glauber model. Incident energies do not show obvious effect on the resulting values across this wide energy range. The extracted quenching factors are found to be strongly dependent on the proton–neutron asymmetry, which is consistent with the recent analysis of knockout reactions but is different from the systematics of transfer and quasi-free knockout reactions. Quenching of single-paricle strengths of carbon isotopes 9−12,14−20C with knockout reactions for incident energies 43-2100 MeV/nucleon.

Systematic investigation of nucleon optical model potentials in (p, d) transfer reactions*

“…Overall, one observes that the values under different OMPs show no significant incident energy dependence when E < 70 MeV, which is consistent with the results of Ref. [39]. However, there are only three points for 28 Si, and the values of 40 Ca scatter considerably, although they are obtained using the same methodology wherein all reactions are analyzed with the same procedure without free parameters.…”

“…However, new precision measurements will be helpful. Satisfactorily, the results with CTOM agree well with the systematics of ( ) reactions at low energies, which is also the energy range of most previous systematic analyses of ( ) and ( ) reactions [9,11,38,39]. Therefore, reanalyzing previous studies by applying CTOM would be worthwhile.…”

“…Such quench-ing of single particle strengths has been attributed to some profound questions in nuclear physics, such as short-and medium-range nucleon-nucleon correlations and long-range correlations from the single-particle motion coupling of the nucleons near the Fermi surface and the collective excitations. Additionally, the reduction factors obtained from the transfer [10,13,38,39,[45][46][47][48], single-nucleon removal [35,36,40,[49][50][51][52][53], and quasifree knockout [54][55][56][57][58][59][60] ) reactions, which are free from the uncertainties of OMPs and are thus deemed to be more reliable, are known to range approximately between 0.4 and 0.7 [47,61]. Therefore, SFs derived from a self-consistent analysis are expectedly quenched by a common factor of approximately , independent of whether the reaction is nucleon adding or removing and whether a neutron or proton is transferred; in addition, the quenching is independent of the mass of the nucleus, reaction type, and angular momentum transfer [47,61].…”

“…A better solution is to confine the and values with reliable nuclear structure theory. The TB-MRM constrains the and values using modern Hartree-Fock (HF) calculations [13,[35][36][37][38][39][40], fixing the diffuseness parameter at fm. The radius parameter is determined by requiring that the root mean square (RMS) radius of the single neutron wave function, , is related to the RMS radius of the corresponding single particle orbital from the HF calculations, , by…”