Direct ab initio calculation of the $^{4}$He nuclear electric dipole polarizability

TL;DR

This paper demonstrates the first ab initio calculation of the $^{4}$He nuclear electric dipole polarizability using large basis diagonalization, achieving convergence and consistency with experimental data.

Contribution

It introduces a feasible method for calculating nuclear electromagnetic sum rules for $A>2$ nuclei via direct diagonalization of the Hamiltonian with high-performance computing.

Findings

Calculated $^{4}$He electric dipole polarizability consistent with experimental data.

Showed numerical tractability and convergence of sum rule calculations.

Compared results with other theoretical approaches and interactions.

Abstract

The calculation of nuclear electromagnetic sum rules by directly diagonalizing the nuclear Hamiltonian in a large basis is numerically challenging and has not been performed for $A>2$ nuclei. With the significant progress of high performance computing, we show that calculating sum rules using numerous discretized continuum states obtained by directly diagonalizing the ab initio no-core shell model Hamiltonian is achievable numerically. Specifically, we calculate the $^{4}$He electric dipole ($E1$) polarizability, that is an inverse energy weighted sum rule, employing the Daejeon16 $NN$ interaction. We demonstrate that the calculations are numerically tractable as the dimension of the basis increases and are convergent. Our results for the $^{4}$He electric dipole polarizability are consistent with the most recent experimental data and are compared with those of other theoretical studies employing different techniques and various interactions.