title: Constraint on 0νββ matrix elements from a novel decay channel of the scissors mode: the case of 154Gd.
abstract: The nucleus (154)Gd is located in a region of the nuclear chart where rapid changes of nuclear deformation occur as a function of particle number. It was investigated using a combination of γ-ray scattering experiments and a γγ-coincidence study following electron capture decay of (154)Tb(m). A novel decay channel from the scissors mode to the first excited 0(+) state was observed. Its transition strength was determined to B(M1;1(sc)(+)→0(2)(+))=0.031(4)μ(N)(2). The properties of the scissors mode of (154)Gd imply a much larger matrix element than previously thought for the neutrinoless double-β decay to the 0(2)(+) state in such a shape-transitional region. Theory indicates an even larger effect for (150)Nd.
authors.affiliation: Institut für Kernphysik, TU Darmstadt, Schlossgartenstraße 9, D-64289 Darmstadt, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Beller
authors.forename: N
authors.initials: N
authors.lastname: Pietralla
authors.forename: J
authors.initials: J
authors.lastname: Barea
authors.forename: M
authors.initials: M
authors.lastname: Elvers
authors.forename: J
authors.initials: J
authors.lastname: Endres
authors.forename: C
authors.initials: C
authors.lastname: Fransen
authors.forename: J
authors.initials: J
authors.lastname: Kotila
authors.forename: O
authors.initials: O
authors.lastname: Möller
authors.forename: A
authors.initials: A
authors.lastname: Richter
authors.forename: T R
authors.initials: TR
authors.lastname: Rodríguez
authors.forename: C
authors.initials: C
authors.lastname: Romig
authors.forename: D
authors.initials: D
authors.lastname: Savran
authors.forename: M
authors.initials: M
authors.lastname: Scheck
authors.forename: L
authors.initials: L
authors.lastname: Schnorrenberger
authors.forename: K
authors.initials: K
authors.lastname: Sonnabend
authors.forename: V
authors.initials: V
authors.lastname: Werner
authors.forename: A
authors.initials: A
authors.lastname: Zilges
authors.forename: M
authors.initials: M
authors.lastname: Zweidinger