Gamma-Ray Angular Distribution, Angular Correlation, Linear Polarization, and Doppler-Shift Attenuation Measurements in the ⁴⁶Ti(α, nγ) ⁴⁹Cr Reaction

Cr49: Towards full spectroscopy up to 4 MeV

“…b) The 2160 keV branch of the 2432 keV level is very small, in agreement with Ref. [10] and in disagreement with NDS [2]. c) The previously reported branch of 2979 keV from the 3251 keV level [2] is not observed.…”

“…Concerning the 1/2 + levels, a large experimental ℓ n =0 pick-up strength is concentrated on a level at 6470 keV, which was interpreted as the T=3/2 IAS of the yrast 1/2 + in 49 V. The 49 Cr 1/2 + level with configuration [211]1/2 + is predicted more than 3 MeV above the one based on the [200]1/2 + orbital, but it is likely fragmented owing to the high level density, while IAS's are more robust against mixing. It may be that some ℓ n =0 strength due to [211]1/2 + orbital was attributed to IAS fragmentation of the T=3/2, I=1/2 + state, leading also in this case to an overestimate of the sum of spectroscopic factors with isotopic spin T > [10].…”

“…This perspective, often named full spectroscopy, became more important recently, also because some properties of non yrast states are fingerprints of nuclear symmetries and supersymmetries [9]. Such information was scanty in γ-spectroscopy, as levels up to about 2.5 MeV had been studied in the reaction 46 Ti(α, nγ) 49 Cr at a bombarding energy of 8 MeV, more than twenty five years ago [10]. We have used the same reaction but, in order to observe non yrast levels in 49 Cr, which are populated with small cross-section, a high efficiency γ-detector array was used.…”