Benchmark calculations for 3H, 4He, 16O and 40Ca with ab-initio coupled-cluster theory

TL;DR

This paper performs ab-initio coupled-cluster calculations for light and medium-mass nuclei using low-momentum interactions, achieving results close to exact methods and providing insights into convergence and accuracy.

Contribution

It introduces benchmark calculations for several nuclei using coupled-cluster theory with low-momentum interactions, demonstrating high accuracy and convergence analysis.

Findings

Results for 3H and 4He are within 70 keV and 10 keV of exact energies.

Practically converged binding energies for 16O and 40Ca are reported.

Comparison with other approaches shows good agreement.

Abstract

We present ab-initio calculations for 3H, 4He, 16O, and 40Ca based on two-nucleon low-momentum interactions Vlowk within coupled-cluster theory. For 3H and 4He, our results are within 70 keV and 10 keV of the corresponding Faddeev and Faddeev-Yakubovsky energies. We study in detail the convergence with respect to the size of the model space and the single-particle basis. For the heavier nuclei, we report practically converged binding energies and compare with other approaches.