Abstract
The low-lying excited states in the neutron-deficient N = Z + 1 nucleus 87 43 Tc 44 have been studied via the fusion-evaporation reaction 54 Fe(36 Ar, 2n1p) 87 Tc at Grand Accélérateur National d'Ions Lourds (GANIL), France. The AGATA spectrometer was used in conjution with the auxiliary NEDA, Neutron Wall, and DIAMANT detector arrays to measure coincident prompt γ-rays, neutrons , and charged particles emitted in the reactions. A level scheme of 87 Tc from the (9/2 + g.s.) state to the (33/2 + 1) state was established based on 6 mutually coincident γ-ray transitions. The constructed level structure exhibits a rotational behavior with a sharp backbending at ω ≈ 0.50 MeV. A decrease in alignment frequency and increase in alignment sharpness in the odd-mass isotonic chains around N = 43 is proposed as an effect of the enhanced isoscalar neutron-proton interactions in odd-mass nuclei when approaching the N = Z line.