https://doi.org/10.1140/epja/s10050-019-00005-x
Regular Article - Experimental Physics
First search for 
decays of naturally occurring Hf nuclides with emission of 
quanta
1
Institute for Nuclear Research, Kyiv, 03028, Ukraine
2
European Commission, Joint Research Centre, Retieseweg 111, 2440, Geel, Belgium
3
National Scientific Center Kharkiv Institute of Physics and Technology, Kharkiv, 61108, Ukraine
4
Karazin Kharkiv National University, Kharkiv, 61022, Ukraine
5
Public Enterprise “Scientific and Technological Center Beryllium”, Kharkiv, 61108, Ukraine
* e-mail: danevich@kinr.kiev.ua
Received:
23
July
2019
Accepted:
23
October
2019
Published online:
9
January
2020
The first ever search for decays to the first excited state in Yb was performed for six isotopes of hafnium (174, 176, 177, 178, 179, 180) using a high purity Hf sample of natural isotopic abundance with a mass of 179.8 g. For 
Hf, also decay to the ground state of 
Yb was searched for thanks to the 
-instability of the daughter nuclide Yb. The measurements were conducted using an ultra-low-background HPGe-detector system located 225 m underground. After 75 days of data taking no decays were detected but lower bounds for the half-lives of the decays were derived on the level of 
a. The decay with the shortest half-life based on theoretical calculation is the decay of 
Hf to the first 
84.3 keV excited level of 
Yb. The experimental lower bound was found to be 
a.
© Società Italiana di Fisica (SIF) and Springer-Verlag GmbH Germany, part of Springer Nature, 2020
