The decay characteristic of $^{22}$Si and its ground-state mass significantly affected by three-nucleon forces

TL;DR

This study investigates the decay properties of the proton-rich nucleus $^{22}$Si, revealing the influence of three-nucleon forces on its ground-state mass and decay modes, supported by experimental data and shell-model calculations.

Contribution

It provides new experimental data on $^{22}$Si decay and demonstrates the significant impact of three-nucleon forces on nuclei near the proton drip line.

Findings

Observation of $eta$-delayed proton and two-proton emissions.

Half-life of $^{22}$Si measured as 27.5 ms.

Mass excess data indicates strong effects of three-nucleon forces.

Abstract

The decay of the proton-rich nucleus $^{22}$Si was studied by a silicon array coupled with germanium clover detectors. Nine charged-particle groups are observed and most of them are recognized as $\beta$-delayed proton emission. A charged-particle group at 5600 keV is identified experimentally as $\beta$-delayed two-proton emission from the isobaric analog state of $^{22}$Al. Another charged-particle emission without any $\beta$ particle at the low energy less than 300 keV is observed. The half-life of $^{22}$Si is determined as 27.5 (18) ms. The experimental results of $\beta$-decay of $^{22}$Si are compared and in nice agreement with shell-model calculations. The mass excess of the ground state of $^{22}$Si deduced from the experimental data shows that three-nucleon (3N) forces with repulsive contributions have significant effects on nuclei near the proton drip line.