Reduction in nuclear size and quadrupole deformation of high-spin isomers of 127,129In

TL;DR

This study uses laser spectroscopy to measure nuclear charge radii and quadrupole moments of high-spin isomers in neutron-rich indium isotopes, revealing size and shape reductions linked to nucleon alignment.

Contribution

It provides new experimental data on nuclear size and shape changes in high-spin isomers near closed shells, challenging current nuclear theories.

Findings

Reduction in charge radius and quadrupole moment in 129In high-spin isomer.

No similar reduction observed in 127In, indicating different nuclear configurations.

Experimental results are not fully explained by existing nuclear models.

Abstract

We employed laser spectroscopy of atomic transitions to measure the nuclear charge radii and electromagnetic properties of the high-spin isomeric states in neutron-rich indium isotopes (Z = 49) near the closed proton and neutron shells at Z = 50 and N = 82. Our data reveal a reduction in the nuclear charge radius and intrinsic quadrupole moment when protons and neutrons are fully aligned in 129In(N = 80), to form the high spin isomer. Such a reduction is not observed in 127In(N = 78), where more complex configurations can be formed by the existence of four neutron-holes. These observations are not consistently described by nuclear theory.