Abstract
Electric quadrupole matrix elements, Mp, for the Jπ = 2+→0+, ΔT = 0, T = 1 transitions across the A = 46 isobaric multiplet 46Cr-46V-46Ti have been measured at GSI with the FRS-LYCCA-AGATA setup. This allows direct insight into the isospin purity of the states of interest by testing the linearity of Mp with respect to Tz. Pairs of nuclei in the T = 1 triplet were studied using identical reaction mechanisms in order to control systematic errors. The Mp values were obtained with two different methodologies: (i) a relativistic Coulomb excitation experiment was performed for 46Cr and 46Ti; (ii) a “stretched target” technique was adopted here, for the first time, for lifetime measurements in 46V and 46Ti. A constant value of Mp across the triplet has been observed. Shell-model calculations performed within the fp shell fail to reproduce this unexpected trend, pointing towards the need of a wider valence space. This result is confirmed by the good agreement with experimental data achieved with an interaction which allows excitations from the underlying sd shell. A test of the linearity rule for all published data on complete T = 1 isospin triplets is presented.
| Original language | English |
|---|---|
| Article number | 134835 |
| Number of pages | 6 |
| Journal | Physics Letters B |
| Volume | 797 |
| Early online date | 13 Aug 2019 |
| DOIs | |
| Publication status | Published - 10 Oct 2019 |
| Externally published | Yes |