Computation of spectroscopic factors with the coupled-cluster method

TL;DR

This paper develops a coupled-cluster method to compute spectroscopic factors, demonstrating its application on oxygen isotopes and analyzing the effects of interaction parameters and center-of-mass treatment.

Contribution

It introduces algebraic equations for one-body overlap functions within coupled-cluster theory and applies them to specific nuclei, advancing computational nuclear structure methods.

Findings

Spectroscopic factors for $^{15}$O and $^{15}$N were calculated from $^{16}$O.

Results show sensitivity to the momentum cutoff in the interaction.

Center-of-mass treatment impacts the computed spectroscopic factors.

Abstract

We present a calculation of spectroscopic factors within coupled-cluster theory. Our derivation of algebraic equations for the one-body overlap functions are based on coupled-cluster equation-of-motion solutions for the ground and excited states of the doubly magic nucleus with mass number $A$ and the odd-mass neighbor with mass $A-1$. As a proof-of-principle calculation, we consider $^{16}$O and the odd neighbors $^{15}$O and $^{15}$N, and compute the spectroscopic factor for nucleon removal from $^{16}$O. We employ a renormalized low-momentum interaction of the $V_{\mathrm{low-}k}$ type derived from a chiral interaction at next-to-next-to-next-to-leading order. We study the sensitivity of our results by variation of the momentum cutoff, and then discuss the treatment of the center of mass.