Calibration of the liquid argon ionization response to low energy electronic and nuclear recoils with DarkSide-50

Agnes P.;Albuquerque I. F. M.;Alexander T.;Alton A. K.;Ave M.;Back H. O.;Batignani G.;Biery K.;Bocci V.;Bonivento W. M.;Bottino B.;Bussino S.;Cadeddu M.;Cadoni M.;Calaprice F.;Caminata A.;Canci N.;Caravati M.;Cariello M.;Carlini M.;Carpinelli M.;Catalanotti S.;Cataudella V.;Cavalcante P.;Cavuoti S.;Chepurnov A.;Cicalo C.;Cocco A. G.;Covone G.;D'Angelo D.;Davini S.;De Candia A.;De Cecco S.;De Filippis G.;De Rosa G.;Derbin A. V.;Devoto A.;D'Incecco M.;Dionisi C.;Dordei F.;Downing M.;D'Urso D.;Fiorillo G.;Franco D.;Gabriele F.;Galbiati C.;Ghiano C.;Giganti C.;Giovanetti G. K.;Gorchakov O.;Goretti A. M.;Grobov A.;Gromov M.;Guan M.;Guardincerri Y.;Gulino M.;Hackett B. R.;Herner K.;Hosseini B.;Hubaut F.;Hungerford E. V.;Ianni A.;Ippolito V.;Keeter K.;Kendziora C. L.;Kochanek I.;Korablev D.;Korga G.;Kubankin A.;Kuss M.;La Commara M.;Lai M.;Li X.;Lissia M.;Longo G.;Machulin I. N.;Mapelli L. P.;Mari S. M.;Maricic J.;Martoff C. J.;Messina A.;Meyers P. D.;Milincic R.;Morrocchi M.;Mougeot X.;Muratova V. N.;Musico P.;Navrer Agasson A.;Nozdrina A. O.;Oleinik A.;Ortica F.;Pagani L.;Pallavicini M.;Pandola L.;Pantic E.;Paoloni E.;Pelczar K.;Pelliccia N.;Picciau E.;Pocar A.;Pordes S.;Poudel S. S.;Pralavorio P.;Ragusa F.;Razeti M.;Razeto A.;Renshaw A. L.;Rescigno M.;Rode J.;Romani A.;Sablone D.;Samoylov O.;Sands W.;Sanfilippo S.;Savarese C.;Schlitzer B.;Semenov D. A.;Shchagin A.;Sheshukov A.;Skorokhvatov M. D.;Smirnov O.;Sotnikov A.;Stracka S.;Suvorov Y.;Tartaglia R.;Testera G.;Tonazzo A.;Unzhakov E. V.;Vishneva A.;Vogelaar R. B.;Wada M.;Wang H.;Wang Y.;Westerdale S.;Wojcik M. M.;Xiao X.;Yang C.;Zuzel G.

2021-01-01

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Abstract

DarkSide-50 has demonstrated the high potential of dual-phase liquid argon time projection chambers in exploring interactions of WIMPs in the GeV/c2 mass range. The technique, based on the detection of the ionization signal amplified via electroluminescence in the gas phase, allows us to explore recoil energies down to the sub-keV range. We report here on the DarkSide-50 measurement of the ionization yield of electronic recoils down to ∼180 eVer, exploiting Ar37 and Ar39 decays, and extrapolated to a few ionization electrons with the Thomas-Imel box model. Moreover, we present a model-dependent determination of the ionization response to nuclear recoils down to ∼500 eVnr, the lowest ever achieved in liquid argon, using in situ neutron calibration sources and external datasets from neutron beam experiments.