In-beam γ-ray and electron spectroscopy of ²⁴⁹^,²⁵¹Md

Abstract

<div lang="en" class="abs"><p class="abs_header">Abstract</p><p>The odd-Z ²⁵¹Md nucleus was studied using combined γ-ray and conversion-electron in-beam spectroscopy. Besides the previously observed rotational band based on the [521]1/2⁻ configuration, another rotational structure has been identified using <em>γ</em>−<em>γ</em> coincidences. The use of electron spectroscopy allowed the rotational bands to be observed over a larger rotational frequency range. Using the transition intensities that depend on the gyromagnetic factor, a [514]7/2⁻ single-particle configuration has been inferred for this band, i.e., the ground-state band. A physical background that dominates the electron spectrum with an intensity of ≃60% was well reproduced by simulating a set of unresolved excited bands. Moreover, a detailed analysis of the intensity profile as a function of the angular momentum provided a method for deriving the orbital gyromagnetic factor, namely \(g_{K}=0.69^{+0.19}_{−0.16}\) for the ground-state band. The odd-Z ²⁴⁹Md was studied using <em>γ</em>-ray in-beam spectroscopy. Evidence for octupole correlations resulting from the mixing of the Δ<em>l</em>=Δ<em>j</em>=3 [521]3/2⁻ and [633]7/2⁺ Nilsson orbitals were found in both ²⁴⁹^,²⁵¹Md. A surprising similarity of the²⁵¹Md ground-state band transition energies with those of the excited band of ²⁵⁵Lr has been discussed in terms of identical bands. Skyrme-Hartree-Fock-Bogoliubov calculations were performed to investigate the origin of the similarities between these bands.</p></div>