Measurement of the Z boson invisible width at $\sqrt{s}=13$ TeV with the ATLAS detector

• Published in: Physics letters. B Vol. 854
• Main Authors: Alberghi, G. L., Antel, C., Barklow, T., Batool, B., Battulga, D., Bechtle, P., Biswal, J. P., Bold, T., Boudreau, J., Bruni, G., Carter, T. M., Cepaitis, V., Chen, S., Danninger, M., Davis-Purcell, B., Di Nardo, R., Djobava, T., Dreyer, E., El Farkh, S., El Jarrari, H., Ezzarqtouni, S., Faraj, M., Farazpay, Z., Farrington, S. M., Fenyuk, A. B., Filipčič, A., Fleck, I., Fortman, A. W., Froch, A., Gallas, E. J., Ghosh, A., Goblirsch-Kolb, M., Grillo, A. A., Gugel, R., Hamer, M., Hampshire, E. J., Hanif, H., Hedberg, V., Heim, S., Hibi, H., Ishino, M., Jejelava, J., Jia, J., Jovicevic, J., Kalderon, C. W., Karkanias, I., Kartvelishvili, V., Kostyukhin, V. V., Krüger, H., Krumnack, N., Kupich, A., Lacasta, C., Lambert, J. E., Le, B., Leban, B., Lee, T. F., Lefebvre, M., Li, S., Li, Z., Lorenzo Martinez, N., Maeda, J., Mc Gowan, J. P., Min, T., Mitsumori, Y., Mlinarevic, T., Nairz, A. M., Nikolic-Audit, I., Oreglia, M. J., Palestini, S., Pan, T., Pontecorvo, L., Popeneciu, G. A., Primavera, M., Pyatiizbyantseva, D., Rembser, C., Ribaric, N., Roberts, B. R., Romano, M., Rozario, Z. M.A., Ruby, A. J., Sawyer, L., Shcherbakova, A., Silva, J. M., Strandberg, S., Styles, N. A., Ta, D., Tapia Araya, S., Theiner, O., Tojo, J., Trzupek, A., Vafeiadis, T., Varvell, K. E., Vishwakarma, A., Walker, R., Wang, S., Wang, Z., Weik, E. J., Yabsley, B., Zerradi, S., Zhao, H.
• Format: Journal Article
• Language: English
• Published: United States Elsevier 10.05.2024
• Subjects: 13000 GeV-cms; associated production; branching ratio; CERN LEP Stor; colliding beams; experimental results; hadroproduction; invisible decay; missing-energy; muon; phase space; PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; scattering; transverse momentum
• ISSN: 0370-2693; 1873-2445

A measurement of the invisible width of the Z boson using events with jets and missing transverse momentum is presented using 37 fb-1 of 13 TeV proton–proton data collected by the ATLAS detector in 2015 and 2016. The ratio of Z → inv to Z → ℓℓ events, where inv refers to non-detected particles and ℓ is either an electron or a muon, is measured and corrected for detector effects. Events with at least one energetic central jet with pT ≥ 110 GeV are selected for both the Z → inv and Z → ℓℓ final states to obtain a similar phase space in the ratio. The invisible width is measured to be 506 ± 2 (stat.) ± 12 (syst.) MeV and is the single most precise recoil-based measurement. The result is in agreement with the most precise determination from LEP and the Standard Model prediction based on three neutrino generations.