Role of Long-Range Correlations on the Quenching of Spectroscopic Factors

TL;DR

This paper investigates how long-range correlations affect the reduction of spectroscopic factors in nuclear isotopes, emphasizing the importance of large model spaces and particle-vibration coupling for accurate predictions.

Contribution

It demonstrates that large model spaces and particle-vibration coupling are essential for accurately predicting spectroscopic factor quenching, advancing microscopic understanding of shell-model phenomena.

Findings

Large model spaces are necessary for accurate predictions.

Particle-vibration coupling is the main mechanism for quenching.

Theoretical results agree with experimental data.

Abstract

We consider the proton and neutron quasiparticle orbits around the closed-shell 56Ni and 48Ca isotopes. It is found that large model spaces (beyond the capability of shell-model applications) are necessary for predicting the quenchings of spectroscopic factors. The particle-vibration coupling is identified as the principal mechanism. Additional correlations--due to configuration with several particle-hole excitations--are estimated using shell-model calculations and generate an extra reduction which is < ~4% for most quasiparticle states. The theoretical calculations nicely agree with (e,e'p) and heavy ion knock-out experiments. These results open a new path for a microscopic understanding of the shell-model.