The (d,He-2) reaction on Mo-96 and the double-beta decay matrix elements for Zr-96

The Mo-96(d,He-2)Nb-96 charge-exchange reaction was investigated at an incident energy of E-d=183.5 MeV. An excitation-energy resolution of 110 keV was achieved. The experiment was performed at KVI, Groningen, using the magnetic spectrometer BBS at three angular positions: 0(degrees),2.5(degrees), and 6(degrees). We found that below 6 MeV almost the entire Gamow-Teller (GT(+)) strength is concentrated in a single state at 0.69 MeV excitation energy. As Mo-96 is the daughter of the beta beta decay nucleus Zr-96, the present result provides information about the nuclear matrix elements active in the 2 nu beta beta decay of Zr-96.