Projected WIMP sensitivity of the XENONnT dark matter experiment

• Published in: Journal of cosmology and astroparticle physics Vol. 2020; no. 11; p. 31
• Main Authors: Aprile, E., Aalbers, J., Agostini, F., Alfonsi, M., Althueser, L., Amaro, F.D., Antochi, V.C., Angelino, E., Angevaare, J.R., Arneodo, F., Barge, D., Baudis, L., Bauermeister, B., Bellagamba, L., Benabderrahmane, M.L., Berger, T., Brown, A., Brown, E., Bruenner, S., Bruno, G., Budnik, R., Capelli, C., Cardoso, J.M.R., Cichon, D., Cimmino, B., Clark, M., Coderre, D., Colijn, A.P., Conrad, J., Cussonneau, J.P., Decowski, M.P., Depoian, A., Gangi, P. Di, Giovanni, A. Di, Stefano, R. Di, Diglio, S., Elykov, A., Eurin, G., Ferella, A.D., Fulgione, W., Gaemers, P., Gaior, R., Galloway, M., Gao, F., Grandi, L., Hasterok, C., Hils, C., Hiraide, K., Hoetzsch, L., Howlett, J., Iacovacci, M., Itow, Y., Joerg, F., Kato, N., Kazama, S., Kobayashi, M., Koltman, G., Kopec, A., Landsman, H., Lang, R.F., Levinson, L., Lin, Q., Lindemann, S., Lindner, M., Lombardi, F., Long, J., Lopes, J.A.M., Fune, E. López, Macolino, C., Mahlstedt, J., Mancuso, A., Manenti, L., Manfredini, A., Marignetti, F., Undagoitia, T. Marrodán, Martens, K., Masbou, J., Masson, D., Mastroianni, S., Messina, M., Miuchi, K., Mizukoshi, K., Molinario, A., Morå, K., Moriyama, S., Mosbacher, Y., Murra, M., Naganoma, J., Ni, K., Oberlack, U., Odgers, K., Palacio, J., Pelssers, B., Peres, R., Pienaar, J., Pizzella, V., Plante, G., Qin, J., Qiu, H., García, D. Ramírez
• Format: Journal Article
• Language: English
• Published: Bristol IOP Publishing 01.11.2020; Institute of Physics (IOP)
• Subjects: Astrophysics; Confidence intervals; Cross-sections; Dark matter; dark matter experiments; dark matter simulations; High Energy Physics - Experiment; Instrumentation and Detectors; Physics; Sensitivity; Statistical analysis; Weakly interacting massive particles; Xenon; data analysis method; dark matter: direct detection; nucleus: recoil; background; activity report; XENON; WIMP: dark matter; WIMP nucleon: scattering; electron: recoil; xenon: liquid; sensitivity
• ISSN: 1475-7516; 1475-7508; 1475-7516
• DOI: 10.1088/1475-7516/2020/11/031

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  cm 2 for a 50 GeV/c 2 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/c 2 WIMP with cross-sections above 2.6×10 −48  cm 2 (5.0×10 −48  cm 2 ) 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  cm 2 (6.0×10 −42  cm 2 ).