Four-body resonances of 7B using the complex scaling method

TL;DR

This paper investigates the resonance states of the proton-rich nucleus 7B using the complex scaling method within a 4He+p+p+p cluster model, predicting five resonances and analyzing mirror symmetry breaking due to Coulomb effects.

Contribution

It applies the complex scaling method to study 7B resonances and reveals the significance of 6Be(2+) components and mirror symmetry breaking in its structure.

Findings

Predicted five resonances of 7B.

Identified the importance of 6Be(2+)-p components.

Showed mirror symmetry breaking due to Coulomb repulsion.

Abstract

We study the resonance spectroscopy of the proton-rich nucleus 7B in the 4He+p+p+p cluster model. Many-body resonances are treated on the correct boundary condition as the Gamow states using the complex scaling method. We predict five resonances of 7B and evaluate the spectroscopic factors of the 6Be-p components. The importance of the 6Be(2+)-p component is shown in several states of 7B, which is a common feature of 7He, a mirror nucleus of 7B. For only the ground state of 7B, the mixing of 6Be(2+) state is larger than that of 6He(2+) in 7He, which indicates the breaking of the mirror symmetry. This is caused by the small energy difference between 7B and the excited 6Be(2+) state, whose origin is the Coulomb repulsion.