Neutrinoless Double-Electron Capture

Abstract

Double-beta processes play a key role in the exploration of neutrino and weak interaction properties, and in the searches for effects beyond the Standard Model. During the last half century many attempts were undertaken to search for double-beta decay with emission of two electrons, especially for its neutrinoless mode ($0\nu 2{\beta }^{-}$), the latter being still not observed. Double-electron capture (2EC) was not in focus so far because of its in general lower transition probability. However, the rate of neutrinoless double-electron capture ($0\nu 2$EC) can experience a resonance enhancement by many orders of magnitude in case the initial and final states are energetically degenerate. In the resonant case, the sensitivity of the $0\nu 2$EC process can approach the sensitivity of the $0\nu 2{\beta }^{-}$ decay in the search for the Majorana mass of neutrinos, right-handed currents, and other new physics. We present an overview of the main experimental and theoretical results obtained during the last decade in this field. The experimental part outlines search results of 2EC processes and measurements of the decay energies for possible resonant $0\nu$2EC transitions. An unprecedented precision in the determination of decay energies with Penning traps has allowed one to refine the values of the degeneracy parameter for all previously known near-resonant decays and has reduced the rather large uncertainties in the estimate of the $0\nu 2$EC half-lives. The theoretical part contains an updated analysis of the electron shell effects and an overview of the nuclear structure models, in which the nuclear matrix elements of the $0\nu 2$EC decays are calculated. One can conclude that the decay probability of $0\nu$2EC can experience a significant enhancement in several nuclides.

68 pages, 14 tables, 19 figures, accepted for publication in Reviews of Modern Physics

References in corpus (39)

• Double Beta Decay, Majorana Neutrinos, and Neutrino Mass
• Colloquium: Majorana Fermions in nuclear, particle and solid-state physics
• Status and Future of Nuclear Matrix Elements for Neutrinoless Double-Beta Decay: A Review
• Energy density functional study of nuclear matrix elements for neutrinoless $\beta \beta$ decay
• Extending the Standard Model Effective Field Theory with the Complete Set of Dimension-7 Operators
• Neutrinoless double beta decay and neutrino mass
• Neutrinoless Double-Beta Decay: a Probe of Physics Beyond the Standard Model
• The Ramsey method in high-precision mass spectrometry with Penning traps: Experimental results
• Separated Oscillatory Fields for High-Precision Penning Trap Mass Spectrometry
• First observation of two-neutrino double electron capture in ${}^{124}$Xe with XENON1T
• Short-range correlations and neutrinoless double beta decay
• TRIGA-SPEC: A setup for mass spectrometry and laser spectroscopy at the research reactor TRIGA Mainz
• Neutrinoless double beta decay in chiral effective field theory: lepton number violation at dimension seven
• Double-beta decay Q values of 130Te, 128Te, and 120Te
• Two-neutrino double beta decay of deformed nuclei within QRPA with realistic interaction
• Recent Progress in Double Beta Decay
• Search for ${\beta }^{+}$EC and ECEC processes in ${}^{74}$Se
• Search for ${\beta }^{+}$EC and ECEC processes in ${}^{112}$Sn and ${\beta }^{-}{\beta }^{-}$ decay of ${}^{124}$Sn to the excited states of ${}^{124}$Te
• Random coincidence of $2\nu 2\beta$ decay events as a background source in bolometric $0\nu 2\beta$ decay experiments
• Extended Black Box Theorem for Lepton Number and Flavor Violating processes
• Comparative study of the double $K$-shell-vacancy production in single- and double-electron capture decay
• Pion dominance in RPV SUSY induced neutrinoless double beta decay
• First results on double beta decay modes of Cd, Te and Zn isotopes with the COBRA experiment
• Experimental study of double beta decay modes using a CdZnTe detector array
• A search for double beta decays of tin isotopes with enhanced sensitivity
• Search for double beta decay of ${}^{136}$Ce and ${}^{138}$Ce with HPGe gamma detector
• A search for various double beta decay modes of tin isotopes
• Search for double beta decay of ${}^{106}$Cd with an enriched ${}^{106}$CdWO${}_4$ crystal scintillator in coincidence with CdWO${}_4$ scintillation counters
• Search for Two-Neutrino Double Electron Capture of ${}^{124}$Xe with XENON100
• Q value and half-life of double-electron capture in Os-184
• Direct decay-energy measurement as a route to the neutrino mass
• BEST potential in testing the eV-scale sterile neutrino explanation of reactor antineutrino anomalies
• New limits on the ${\beta }^{+}$EC and ECEC processes in ${}^{120}$Te
• First search for $2\epsilon$ and $\epsilon {\beta }^{+}$ decay of ${}^{174}$Hf
• First direct search for $2\epsilon$ and $\epsilon {\beta }^{+}$ decay of ${}^{144}$Sm and $2{\beta }^{-}$ decay of ${}^{154}$Sm
• Improved limits on ${\beta }^{+}$EC and ECEC processes in ${}^{74}$Se
• On ${}^{146}$Nd, ${}^{144}$Sm and other unexplored 2$\beta$ decay isotopes
• Double Beta Decays into Excited States in ${}^{110}$Pd and ${}^{102}$Pd
• Search for double beta decay with HPGe detectors at the Gran Sasso underground laboratory

Cited by in corpus (23)

• Toward the discovery of matter creation with neutrinoless double-beta decay
• A Next-Generation Liquid Xenon Observatory for Dark Matter and Neutrino Physics
• Unraveling the $0\nu \beta \beta$ Decay Mechanisms
• ${}^{159}$Dy electron-capture: a strong new candidate for neutrino mass determination
• Updated evaluation of potential ultra-low Q value $\beta$-decay candidates
• Observation of an ultra-low $Q$-value electron-capture channel decaying to ${}^{75}$As via high-precision mass measurement
• Spontaneous double alpha decay: First experimental limit and prospects of investigation
• Inferring the nature of active neutrinos: Dirac or Majorana?
• $g_{\mathrm{A}}$-sensitive $\beta$ spectral shapes in the mass $A=86-99$ region assessed by the nuclear shell model
• Shake-off in the 164Er neutrinoless double electronic capture and the dark matter puzzle
• Theoretical analysis and predictions for the double electron capture of ${}^{124}$Xe
• New experimental limits on double-beta decay of osmium
• Search for double $\beta$-decay modes of ${}^{64}$Zn using purified zinc
• Probing the non-standard neutrino interactions using quantum statistics
• Combining Hybrid and Opaque Scintillator Techniques in the Search for Double Beta Plus Decays
• ZnO-based scintillating bolometers: New prospects to study double beta decay of ${}^{64}$Zn
• New limits on double-beta decay of ${}^{190}$Pt and ${}^{198}$Pt
• Search for rare alpha and double beta decays of Yb isotopes to excited levels of daughter nuclei
• Neutrino Mass Matrix in Neutrino-Related Processes
• Gauge invariance of quantum electrodynamics of multi-electron atoms
• Status and Perspectives of Neutrino Physics
• Large-scale shell-model study of 2$\nu$ECEC process in ${}^{78}$Kr
• Exchange contribution to the variance of the excitation energy of the electron shell of the daughter atom in double-$\beta$ decay