Liquid argon light collection and veto modeling in GERDA Phase II.
M AgostiniA AlexanderG R AraujoA M BakalyarovM BalataI BarabanovL BaudisC BauerS BelogurovA BettiniL BezrukovV BiancacciE BossioV BotheR BrugneraA CaldwellS CalgaroC CattadoriA ChernogorovP-J ChiuT ComellatoV D'AndreaE V DemidovaA Di GiacintoN Di MarcoE DoroshkevichF FischerM FominaA GangapshevA GarfagniniC GoochP GrabmayrV GurentsovK GusevJ HakenmüllerS HemmerW HofmannM HultL V InzhechikJ Janicskó CsáthyJ JochumM JunkerV KazalovY KermaïdicH KhushbakhtT KihmK KilgusI V KirpichnikovA KlimenkoK T KnöpfleO KochetovV N KornoukhovP KrauseV V KuzminovM LaubensteinB LehnertM LindnerI LippiA LubashevskiyB LubsandorzhievG LutterC MacolinoB MajorovitsW ManeschgL ManzanillasG MarshallM MiloradovicR MingazhevaM MisiaszekM MorellaY MüllerI NemchenokM NeubergerL PandolaK PelczarL PertoldiP PiseriA PulliaL RauscherM RedchukS RiboldiN RumyantsevaC SadaS SailerF SalamidaS SchönertJ SchreinerM SchüttA-K SchützO SchulzM SchwarzB SchwingenheuerO SelivanenkoE ShevchikM ShirchenkoL ShtembariH SimgenA SmolnikovD StukovS SullivanA A VasenkoA VeresnikovaC VignoliK von SturmA WegmannT WesterC WiesingerM WojcikE YanovichB ZatschlerI ZhitnikovS V ZhukovD ZinatulinaA ZschockeA J ZsigmondK ZuberG Zuzelnull nullPublished in: The European physical journal. C, Particles and fields (2023)
The ability to detect liquid argon scintillation light from within a densely packed high-purity germanium detector array allowed the Gerda experiment to reach an exceptionally low background rate in the search for neutrinoless double beta decay of 76 Ge. Proper modeling of the light propagation throughout the experimental setup, from any origin in the liquid argon volume to its eventual detection by the novel light read-out system, provides insight into the rejection capability and is a necessary ingredient to obtain robust background predictions. In this paper, we present a model of the Gerda liquid argon veto, as obtained by Monte Carlo simulations and constrained by calibration data, and highlight its application for background decomposition.