First evidence for chirality in Tc isotopes: Spectroscopy of 100Tc

Excited states in ¹⁰⁰Tc have been studied using the ⁹⁶Zr( ⁷Li, 3n) reaction at a beam energy of 27 MeV. In the present work, evidence has been found for a second I = 1 band decaying via several stretched dipole transitions to the previously known I = 1 negative-parity band. Comparison of these data with those in neighbouring nuclei and also against recently reported criteria for chiral bands in nuclei, suggests that the two structures can be interpreted as chiral partners. Core quasi-particle coupling model calculations show reasonable agreement with the data and generally support the chiral interpretation of the states.