Rare multi-nucleon decays with the full data sets of the Majorana Demonstrator

Abstract

The Majorana Demonstrator was an ultra-low-background experiment designed for neutrinoless double-beta decay ($0\nu \beta \beta$) investigation in ${}^{76}$Ge. Located at the Sanford Underground Research Facility in Lead, South Dakota, the Demonstrator utilized modular high-purity Ge detector arrays within shielded vacuum cryostats, operating deep underground. The arrays, with a capacity of up to 40.4 kg (27.2 kg enriched to $\sim 88\%$ in ${}^{76}$Ge), have accumulated the full data set, totaling 64.5 kg yr of enriched active exposure and 27.4 kg yr of exposure for natural detectors. Our updated search improves previously explored three-nucleon decay modes in Ge isotopes, setting new partial lifetime limits of $1.83\times 10^{26}$ years (90\% confidence level) for ${}^{76}$Ge($ppp$) $\to$ ${}^{73}$Cu e${}^{+}{\pi }^{+}{\pi }^{+}$ and ${}^{76}$Ge($ppn$) $\to$ ${}^{73}$Zn e${}^{+}{\pi }^{+}$. The partial lifetime limit for the fully inclusive tri-proton decay mode of ${}^{76}$Ge is found to be $2.1\times 10^{25}$ yr. Furthermore, we have updated limits for corresponding multi-nucleon decays.

References in corpus (23)

• A Unified Approach to the Classical Statistical Analysis of Small Signals
• Large-Mass Ultra-Low Noise Germanium Detectors: Performance and Applications in Neutrino and Astroparticle Physics
• Search for Proton Decay via $p\to e^{+}{\pi }^0$ and $p\to {\mu }^{+}{\pi }^0$ in 0.31 megaton$\cdot$years exposure of the Super-Kamiokande Water Cherenkov Detector
• \textsc{MaGe} - a {\sc Geant4}-based Monte Carlo Application Framework for Low-background Germanium Experiments
• The Majorana Demonstrator Radioassay Program
• Final Result of the MAJORANA DEMONSTRATOR's Search for Neutrinoless Double-$\beta$ Decay in ${}^{76}$Ge
• Inclusive Nucleon Decay Searches as a Frontier of Baryon Number Violation
• Gauged Baryon Parity and Nucleon Stability
• Search for dinucleon decay into pions at Super-Kamiokande
• Multi-site event discrimination for the MAJORANA DEMONSTRATOR
• Search for Nucleon and Dinucleon Decays with an Invisible Particle and a Charged Lepton in the Final State at the Super-Kamiokande Experiment
• Muon Flux Measurements at the Davis Campus of the Sanford Underground Research Facility with the Majorana Demonstrator Veto System
• The Majorana Demonstrator calibration system
• $\alpha$-event Characterization and Rejection in Point-Contact HPGe Detectors
• Search for nucleon decays with EXO-200
• The MAJORANA DEMONSTRATOR Readout Electronics System
• Search for Tri-Nucleon Decay in the Majorana Demonstrator
• ADC Nonlinearity Correction for the MAJORANA DEMONSTRATOR
• Charge Trapping and Energy Performance of the MAJORANA DEMONSTRATOR
• A hidden symmetry in the Standard Model
• Search for tri-nucleon decays of ${}^{76}$Ge in GERDA
• Energy Calibration of Germanium Detectors for the MAJORANA DEMONSTRATOR
• Signatures of muonic activation in the Majorana Demonstrator