title: Resonant enhancement of neutrinoless double-electron capture in 152Gd.
abstract: In the search for the nuclide with the largest probability for neutrinoless double-electron capture, we have determined the Q(ϵϵ) value between the ground states of (152)Gd and (152)Sm by Penning-trap mass-ratio measurements. The new Q(ϵϵ) value of 55.70(18) keV results in a half-life of 10(26)  yr for a 1 eV neutrino mass. With this smallest half-life among known 0νϵϵ transitions, (152)Gd is a promising candidate for the search for neutrinoless double-electron capture.
authors.affiliation: Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Eliseev
authors.forename: C
authors.initials: C
authors.lastname: Roux
authors.forename: K
authors.initials: K
authors.lastname: Blaum
authors.forename: M
authors.initials: M
authors.lastname: Block
authors.forename: C
authors.initials: C
authors.lastname: Droese
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authors.lastname: Herfurth
authors.forename: H-J
authors.initials: HJ
authors.lastname: Kluge
authors.forename: M I
authors.initials: MI
authors.lastname: Krivoruchenko
authors.forename: Yu N
authors.initials: YN
authors.lastname: Novikov
authors.forename: E
authors.initials: E
authors.lastname: Minaya Ramirez
authors.forename: L
authors.initials: L
authors.lastname: Schweikhard
authors.forename: V M
authors.initials: VM
authors.lastname: Shabaev
authors.forename: F
authors.initials: F
authors.lastname: Simkovic
authors.forename: I I
authors.initials: II
authors.lastname: Tupitsyn
authors.forename: K
authors.initials: K
authors.lastname: Zuber
authors.forename: N A
authors.initials: NA
authors.lastname: Zubova