Projected WIMP sensitivity of the XENONnT dark matter experiment

E. Aprile , J. Aalbers , F. Agostini , M. Alfonsi , L. Althueser , F.D. Amaro , V.C. Antochi , E. Angelino , J.R. Angevaare , F. Arneodo , D. Barge , L. Baudis , B. Bauermeister , L. Bellagamba , M.L. Benabderrahmane , T. Berger , A. Brown , E. Brown , S. Bruenner , G. Bruno , R. Budnik , C. Capelli , J.M.R. Cardoso , D. Cichon , B. Cimmino , M. Clark , D. Coderre , A.P. Colijn , J. Conrad , J.P. Cussonneau (1) , M.P. Decowski , A. Depoian , P. Di Gangi , A. Di Giovanni , R. Di Stefano , S. Diglio (1) , A. Elykov , G. Eurin , A.D. Ferella , W. Fulgione , P. Gaemers , R. Gaior (2) , M. Galloway , F. Gao , L. Grandi , C. Hasterok , C. Hils , K. Hiraide , L. Hoetzsch , J. Howlett , M. Iacovacci , Y. Itow , F. Joerg , N. Kato , S. Kazama , M. Kobayashi , G. Koltman , A. Kopec , H. Landsman , R.F. Lang , L. Levinson , Q. Lin , S. Lindemann , M. Lindner , F. Lombardi , J. Long , J.A.M. Lopes , E. López Fune (2) , C. Macolino (3) , J. Mahlstedt , A. Mancuso , L. Manenti , A. Manfredini , F. Marignetti , T. Marrodán Undagoitia , K. Martens , J. Masbou (1) , D. Masson , S. Mastroianni , M. Messina , K. Miuchi , K. Mizukoshi , A. Molinario , K. Morå , S. Moriyama , Y. Mosbacher , M. Murra , J. Naganoma , K. Ni , U. Oberlack , K. Odgers , J. Palacio (1) , B. Pelssers , R. Peres , J. Pienaar , V. Pizzella , G. Plante , J. Qin , H. Qiu , D. Ramírez García , S. Reichard , A. Rocchetti , N. Rupp , J.M.F. dos Santos , G. Sartorelli , N. Šarčević , M. Scheibelhut , J. Schreiner , D. Schulte , M. Schumann , L. Scotto Lavina (2) , M. Selvi , F. Semeria , P. Shagin , E. Shockley , M. Silva , H. Simgen , A. Takeda , C. Therreau (1) , Dominique Thers (1) , F. Toschi , G. Trinchero , C. Tunnell , K. Valerius , M. Vargas , G. Volta , H. Wang , Y. Wei , C. Weinheimer , M. Weiss , D. Wenz , C. Wittweg , Z. Xu , M. Yamashita , J. Ye , G. Zavattini , Y. Zhang , T. Zhu , J.P. Zopounidis. (2)

1 SUBATECH - Laboratoire de physique subatomique et des technologies associées
2 LPNHE (UMR_7585) - Laboratoire de Physique Nucléaire et de Hautes Énergies
3 IJCLab - Laboratoire de Physique des 2 Infinis Irène Joliot-Curie

XENONnT is a dark matter direct detection experiment, utilizing 5.9 t of instrumented liquid xenon, located at the INFN Laboratori Nazionali del Gran Sasso. In this work, we predict the experimental background and project the sensitivity of XENONnT to the detection of weakly interacting massive particles (WIMPs). The expected average differential background rate in the energy region of interest, corresponding to (1, 13) keV and (4, 50) keV for electronic and nuclear recoils, amounts to 12.3 ± 0.6 (keV t y)-1 and (2.2± 0.5)× 10−3 (keV t y)-1, respectively, in a 4 t fiducial mass. We compute unified confidence intervals using the profile construction method, in order to ensure proper coverage. With the exposure goal of 20 t y, the expected sensitivity to spin-independent WIMP-nucleon interactions reaches a cross-section of 1.4×10−48 cm2 for a 50 GeV/c2 mass WIMP at 90% confidence level, more than one order of magnitude beyond the current best limit, set by XENON1T . In addition, we show that for a 50 GeV/c2 WIMP with cross-sections above 2.6×10−48 cm2 (5.0×10−48 cm2) the median XENONnT discovery significance exceeds 3σ (5σ). The expected sensitivity to the spin-dependent WIMP coupling to neutrons (protons) reaches 2.2×10−43 cm2 (6.0×10−42 cm2).

Mots clés: xenon: liquid; sensitivity; background; data analysis method; activity report; XENON; WIMP: dark matter; dark matter: direct detection; WIMP nucleon: scattering; nucleus: recoil; electron: recoil

Domaines: Instrumentations et Détecteurs [physics.ins-det]; Astrophysique [astro-ph]; Physique des Hautes Energies - Expérience [hep-ex]

E. Aprile, J. Aalbers, F. Agostini, M. Alfonsi, L. Althueser, et al.. Projected WIMP sensitivity of the XENONnT dark matter experiment. JCAP, 2020, 11, pp.031. ⟨10.1088/1475-7516/2020/11/031⟩. ⟨hal-02911946⟩