First limit on neutrinoless quadruple β decay of Nd 150 to the 01+ state of Gd 150


Journal Article

© 2018 American Physical Society. Background: Observation of lepton number violation via detection of neutrinoless double β decay requires that the neutrino be a Majorana particle. If the neutrino is a Dirac particle, a potential lepton-number violating process is neutrinoless quadruple β decay. Only a few nuclei can undergo neutrinoless quadruple β decay; one of these nuclei is Nd150. Purpose: This study yields the first half-life limit of the neutrinoless quadruple β decay to the excited 01+ state of Gd150. Methods: We searched for neutrinoless quadruple β decay events to excited final states of Gd150 by detecting the deexcitation γ rays of the daughter nucleus in coincidence. These γ rays have energies of 569.031 and 638.050 keV, and are emitted in coincidence through a 01+→21+→0gs+ transition. Results: The enriched Nd2O3 sample consisted of 40.33±0.02 g Nd150 and was observed for 642.8 days at the Kimballton Underground Research Facility. A half-life limit for the decay to the 01+ state of Gd150 was found to be T1/2>1.76×1020 years (90% CL). Conclusions: We report the first search for this decay to excited final states. Though the predicted half-life of this decay is many orders of magnitudes larger, constraining this value experimentally is vital to check for potential enhancements to the decay rate.

Full Text

Duke Authors

Cited Authors

  • Kidd, MF; Tornow, W

Published Date

  • November 9, 2018

Published In

Volume / Issue

  • 98 / 5

Electronic International Standard Serial Number (EISSN)

  • 2469-9993

International Standard Serial Number (ISSN)

  • 2469-9985

Digital Object Identifier (DOI)

  • 10.1103/PhysRevC.98.055501

Citation Source

  • Scopus