Precise electromagnetic tests of ab-initio calculations of light nuclei: States in $^{10}$Be

TL;DR

This study measures lifetimes of specific states in $^{10}$Be using improved DSAM techniques to test ab-initio nuclear calculations, providing new experimental data and comparing it with advanced GFMC theoretical models.

Contribution

It offers precise lifetime measurements of $^{10}$Be states and compares these results with new GFMC calculations, advancing the validation of ab-initio nuclear models.

Findings

Measured the lifetime of the 2+_1 state at 3.37 MeV as 205 fs.

Determined the B(E2) value for the 2+_2 state at 5.96 MeV as 0.11 e^2fm^4.

Provided experimental data that discriminate between different nuclear Hamiltonians.

Abstract

In order to test {\it ab-initio} calculations of light nuclei, we have remeasured lifetimes in $^{10}$Be using the Doppler Shift Attenuation Method (DSAM) following the $^{7}$Li($^7$Li,$\alpha$)$^{10}$Be reaction at 8 and 10 MeV. The new experiments significantly reduce systematic uncertainties in the DSAM technique. The J$^{\pi}$ = $2^+_1$ state at 3.37 MeV has $\tau$ = 205${\pm}$(5)$_{stat}\pm$(7)$_{sys}$ fs corresponding to a $B$($E2\downarrow$) of 9.2(3) $e^2$fm$^4$ in broad agreement with many calculations. The J$^{\pi}$ = $2^+_2$ state at 5.96 MeV was found to have a $B$($E2\downarrow$) of 0.11(2) $e^2$fm$^4$ and provides a more discriminating test of nuclear models. New Green's Function Monte Carlo (GFMC) calculations for these states and transitions with a number of Hamiltonians are also reported and compared to experiment.