First search for double- decay of platinum by ultra-low background HP Ge spectrometry

P. Belli; R. Bernabei; F. Cappella; R. Cerulli; F. A. Danevich; A. Di Marco; A. Incicchitti; M. Laubenstein; S. S. Nagorny; S. Nisi; O. G. Polischuk; V. I. Tretyak

doi:10.1140/epja/i2011-11091-6

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2023 Impact factor 2.6

Hadrons and Nuclei

Eur. Phys. J. A (2011) 47: 91
https://doi.org/10.1140/epja/i2011-11091-6

Regular Article - Experimental Physics

First search for double- $\beta$ decay of platinum by ultra-low background HP Ge $\gamma$ spectrometry

P. Belli¹, R. Bernabei¹^,2^*, F. Cappella³^,4, R. Cerulli⁵, F. A. Danevich⁶, A. Di Marco¹, A. Incicchitti³^,4, M. Laubenstein⁵, S. S. Nagorny⁶, S. Nisi⁵, O. G. Polischuk⁶ and V. I. Tretyak⁶

¹ INFN Sezione di Roma “Tor Vergata”, I-00133, Rome, Italy
² Dipartimento di Fisica, Università di Roma “Tor Vergata”, I-00133, Roma, Italy
³ INFN Sezione di Roma, I-00185, Rome, Italy
⁴ Dipartimento di Fisica, Università di Roma “La Sapienza”, I-00185, Roma, Italy
⁵ Laboratori Nazionali del Gran Sasso, INFN, I-67010, Assergi (Aq), Italy
⁶ Institute for Nuclear Research, MSP 03680, Kyiv, Ukraine

^* e-mail: rita.bernabei@roma2.infn.it

Received: 12 February 2011
Accepted: 15 July 2011
Published online: 8 August 2011

Abstract

A search for double- $\beta$ processes in ¹⁹⁰Pt and ¹⁹⁸Pt was realized with the help of ultra-low background HP Ge 468cm^3 $\gamma$ spectrometer in the underground Gran Sasso National Laboratories of the INFN (Italy). After 1815 h of data taking with 42.5g platinum sample, T _1/2 limits on 2 $\beta$ processes in ¹⁹⁰Pt ( $\varepsilon$ $\beta^{+}_{}$ and 2 $\varepsilon$ have been established on the level of 10¹⁴-10¹⁶y, 3 to 4 orders of magnitude higher than those known previously. In particular, a possible resonant double-electron capture in ¹⁹⁰Pt was restricted on the level of 2.9×10¹⁶ y at 90% C.L. In addition, T _1/2 limit on 2 $\beta^{-}_{}$ decay of ¹⁹⁸Pt (2 $\nu$ +0 $\nu$ ) to the 2⁺ ₁ excited level of ¹⁹⁸Hg has been set at the first time: T _1/2 > 3.5×10¹⁸ y. The radiopurity level of the used platinum sample is reported.