The Performance of the Muon Veto of the GERDA Experiment

Abstract

Low background experiments need a suppression of cosmogenically induced events. The GERDA experiment located at LNGS is searching for the neutrinless double beta decay of ${}^{76}$Ge. It is equipped with an active muon veto the main part of which is a water Cherenkov veto with 66 PMTs in the watertank surrounding the GERDA cryostat. With this system 806 live days have been recorded, 491 days were combined muon-germanium data. A muon detection efficiency of ${\epsilon }_{\mu d}=(99.935\pm 0.015)$ \% was found in a Monte Carlo simulation for the muons depositing energy in the germanium detectors. By examining coincident muon-germanium events a rejection efficiency of ${\epsilon }_{\mu r}=(99.2_{-0.4}^{+0.3})$ \% was found. Without veto condition the muons by themselves would cause a background index of ${\text{BI}}_{\mu }=(3.16\pm 0.85)\times 10^{-3}$ cts/(keV$\cdot$kg$\cdot$yr) at $Q_{\beta \beta }$.

11pages, 14 figures

References in corpus (2)

• \textsc{MaGe} - a {\sc Geant4}-based Monte Carlo Application Framework for Low-background Germanium Experiments
• Results on $\beta \beta$ decay with emission of two neutrinos or Majorons in ${}^{76}$Ge from GERDA Phase I

Cited by in corpus (13)

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• Probing Majorana neutrinos with double-$\beta$ decay
• Upgrade for Phase II of the GERDA Experiment
• The first search for bosonic super-WIMPs with masses up to 1 MeV/c${}^2$ with GERDA
• Flux Modulations seen by the Muon Veto of the GERDA Experiment
• Final Results of GERDA on the Two-Neutrino Double-$\beta$ Decay Half-Life of ${}^{76}$Ge
• Limit on the Radiative Neutrinoless Double Electron Capture of ${}^{36}$Ar from GERDA Phase I
• Virtual depth by active background suppression: Revisiting the cosmic muon induced background of GERDA Phase II
• Neutrinoless Double Beta Decay with Germanium Detectors: 10${}^{26}$ yr and Beyond
• Design and Performance of the GERDA Low-Background Cryostat for Operation in Water
• Optical response of highly reflective film used in the water Cherenkov muon veto of the XENON1T dark matter experiment