Probing the quantum phase transition around $N\approx60$ via mass measurements of technetium isotopes

TL;DR

This study measures the masses of neutron-rich technetium isotopes near N=60, revealing deviations from previous data and providing insights into the nuclear shape transition around this neutron number.

Contribution

The paper presents new high-precision mass measurements of $^{104-106}$Tc isotopes, clarifying their role in the nuclear shape transition near N=60.

Findings

Mass deviations from previous evaluations were observed.

Updated $Q_\beta$ values align with prior measurements.

Technetium isotopes around N=60 are not part of shape coexistence island.

Abstract

The masses of neutron-rich $^{104-106}$Tc isotopes were measured using the JYFLTRAP double Penning trap and found to deviate from the Atomic Mass Evaluation 2020 by $-79(25)$, $40(12)$ and $94(41)$ keV, respectively. In the case of $^{105,106}$Tc, the updated $Q_\beta$ values are in agreement with a previous JYFLTRAP measurement, disagreeing with the values from the mass evaluation. The new mass values result in a more linear trend in two-neutron separation energies indicating that technetium ($Z=43$) isotopes around $N \approx 60$ are not a part of the island of shape coexistence around $^{100}$Zr$_{60}$.