Precision mass measurement of ^173 Hf for nuclear structure of ^173 Lu and the γ process

We report on the precise mass measurement of the ^173 Hf isotope performed at the Ion Guide Isotope Separator On-Line facility using the JYFLTRAP double Penning trap mass spectrometer. The new mass-excess value, ME = -55390.8(30) keV, is in agreement with the literature while being nine times more precise. The newly determined ^173 Hf electron-capture Q value, Q_EC = 1490.2(34) keV, allows us to firmly reject the population of an excited state at 1578 keV in ^173 Lu and 11 transitions tentatively assigned to the decay of ^173 Hf. Our refined mass value of ^173 Hf reduces mass-related uncertainties in the reaction rate of ^174 Hf (γ ,n)^173 Hf. Thus, the rate for the main photodisintegration destruction channel of the p nuclide ^174 Hf in the relevant temperature region for the γ process is better constrained.