A test of light-lepton universality in the rates of inclusive semileptonic $B$-meson decays at Belle II
Creators: name: Belle II Collaboration
name: Aggarwal, L.
name: Ahmed, H.
name: Aihara, H.
name: Akopov, N.
name: Aloisio, A.
name: Ky, N. Anh
name: Asner, D. M.
name: Atmacan, H.
name: Aushev, T.
name: Aushev, V.
name: Bae, H.
name: Bahinipati, S.
name: Bambade, P.
name: Banerjee, Sw.
name: Bansal, S.
name: Barrett, M.
name: Baudot, J.
name: Bauer, M.
name: Baur, A.
name: Beaubien, A.
name: Becker, J.
name: Bennett, J. V.
name: Bernieri, E.
name: Bernlochner, F. U.
name: Bertacchi, V.
name: Bertemes, M.
name: Bertholet, E.
name: Bessner, M.
name: Bettarini, S.
name: Bhardwaj, V.
name: Bhuyan, B.
name: Bianchi, F.
name: Bilka, T.
name: Bilokin, S.
name: Biswas, D.
name: Bodrov, D.
name: Borah, J.
name: Bozek, A.
name: Bračko, M.
name: Briere, R. A.
name: Browder, T. E.
name: Budano, A.
name: Bussino, S.
name: Campajola, M.
name: Cao, L.
name: Casarosa, G.
name: Cecchi, C.
name: Cerasoli, J.
name: Chang, M. -C.
name: Cheaib, R.
name: Cheema, P.
name: Chekelian, V.
name: Cheon, B. G.
name: Chilikin, K.
name: Chirapatpimol, K.
name: Cho, H. -E.
name: Cho, K.
name: Cho, S. -J.
name: Choi, S. -K.
name: Choudhury, S.
name: Cochran, J.
name: Corona, L.
name: Cunliffe, S.
name: Dattola, F.
name: De La Cruz-Burelo, E.
name: De La Motte, S. A.
name: De Nardo, G.
name: De Pietro, G.
name: de Sangro, R.
name: Destefanis, M.
name: Dhamija, R.
name: Di Capua, F.
name: Dingfelder, J.
name: Doležal, Z.
name: Dong, T. V.
name: Dorigo, M.
name: Dossett, D.
name: Dreyer, S.
name: Dubey, S.
name: Dujany, G.
name: Ecker, P.
name: Eliachevitch, M.
name: Feichtinger, P.
name: Ferber, T.
name: Ferlewicz, D.
name: Fillinger, T.
name: Finocchiaro, G.
name: Fodor, A.
name: Forti, F.
name: Frey, A.
name: Fulsom, B. G.
name: Gabrielli, A.
name: Ganiev, E.
name: Garcia-Hernandez, M.
name: Gaudino, G.
name: Gaur, V.
name: Gaz, A.
name: Gellrich, A.
name: Ghevondyan, G.
name: Giordano, R.
name: Giri, A.
name: Glazov, A.
name: Gobbo, B.
name: Godang, R.
name: Goldenzweig, P.
name: Gradl, W.
name: Grammatico, T.
name: Granderath, S.
name: Graziani, E.
name: Gruberová, Z.
name: Gu, T.
name: Gudkova, K.
name: Halder, S.
name: Hara, T.
name: Hayasaka, K.
name: Hayashii, H.
name: Hazra, S.
name: Hearty, C.
name: Hedges, M. T.
name: de la Cruz, I. Heredia
name: Villanueva, M. Hernández
name: Hershenhorn, A.
name: Higuchi, T.
name: Hill, E. C.
name: Hohmann, M.
name: Hsu, C. -L.
name: Iijima, T.
name: Inami, K.
name: Inguglia, G.
name: Ipsita, N.
name: Ishikawa, A.
name: Ito, S.
name: Itoh, R.
name: Iwasaki, M.
name: Jacobs, W. W.
name: Jang, E. -J.
name: Ji, Q. P.
name: Jia, S.
name: Jin, Y.
name: Junkerkalefeld, H.
name: Kaleta, M.
name: Kaliyar, A. B.
name: Karyan, G.
name: Kawasaki, T.
name: Kiesling, C.
name: Kim, C. -H.
name: Kim, D. Y.
name: Kim, K. -H.
name: Kim, Y. -K.
name: Kindo, H.
name: Kinoshita, K.
name: Kodyš, P.
name: Kohani, S.
name: Kojima, K.
name: Korobov, A.
name: Korpar, S.
name: Kovalenko, E.
name: Kowalewski, R.
name: Križan, P.
name: Krokovny, P.
name: Kumar, J.
name: Kumar, R.
name: Kumara, K.
name: Kuzmin, A.
name: Kwon, Y. -J.
name: Lacaprara, S.
name: Lange, J. S.
name: Laurenza, M.
name: Leboucher, R.
name: Diberder, F. R. Le
name: Levit, D.
name: Lewis, P. M.
name: Li, L. K.
name: Libby, J.
name: Liptak, Z.
name: Liu, Q. Y.
name: Liu, Z. Q.
name: Liventsev, D.
name: Longo, S.
name: Lueck, T.
name: Lyu, C.
name: Ma, Y.
name: Maggiora, M.
name: Maharana, S. P.
name: Maiti, R.
name: Maity, S.
name: Manfredi, R.
name: Manoni, E.
name: Manthei, A. C.
name: Mantovano, M.
name: Marinas, C.
name: Martel, L.
name: Martellini, C.
name: Martini, A.
name: Massaccesi, L.
name: Masuda, M.
name: Matsuoka, K.
name: Matvienko, D.
name: Maurya, S. K.
name: McKenna, J. A.
name: Meier, F.
name: Merola, M.
name: Metzner, F.
name: Milesi, M.
name: Miller, C.
name: Miyabayashi, K.
name: Mizuk, R.
name: Mohanty, G. B.
name: Moneta, S.
name: Mrvar, M.
name: Mussa, R.
name: Nakamura, I.
name: Nakamura, K. R.
name: Nakao, M.
name: Nakazawa, Y.
name: Charan, A. Narimani
name: Naruki, M.
name: Narwal, D.
name: Natochii, A.
name: Nayak, L.
name: Nazaryan, G.
name: Nisar, N. K.
name: Nishida, S.
name: Ono, H.
name: Onuki, Y.
name: Oskin, P.
name: Pakhlov, P.
name: Pakhlova, G.
name: Paladino, A.
name: Panta, A.
name: Pardi, S.
name: Park, H.
name: Park, J.
name: Paschen, B.
name: Passeri, A.
name: Patra, S.
name: Paul, S.
name: Pedlar, T. K.
name: Peruzzi, I.
name: Peschke, R.
name: Pestotnik, R.
name: Piilonen, L. E.
name: Angioni, G. Pinna
name: Podesta-Lerma, P. L. M.
name: Podobnik, T.
name: Pokharel, S.
name: Polat, L.
name: Praz, C.
name: Prell, S.
name: Prencipe, E.
name: Prim, M. T.
name: Purwar, H.
name: Rad, N.
name: Rados, P.
name: Raeuber, G.
name: Reif, M.
name: Reiter, S.
name: Ripp-Baudot, I.
name: Rizzo, G.
name: Rizzuto, L. B.
name: Rocchetti, P.
name: Roney, J. M.
name: Rostomyan, A.
name: Rout, N.
name: Sanders, D. A.
name: Sandilya, S.
name: Sangal, A.
name: Santelj, L.
name: Sato, Y.
name: Scavino, B.
name: Schwanda, C.
name: Seino, Y.
name: Selce, A.
name: Senyo, K.
name: Sevior, M. E.
name: Sfienti, C.
name: Shan, W.
name: Sharma, C.
name: Shen, C. P.
name: Shillington, T.
name: Shiu, J. -G.
name: Simon, F.
name: Singh, J. B.
name: Skorupa, J.
name: Sobie, R. J.
name: Soffer, A.
name: Sokolov, A.
name: Solovieva, E.
name: Spataro, S.
name: Spruck, B.
name: Starič, M.
name: Stefkova, S.
name: Stroili, R.
name: Sue, Y.
name: Sumihama, M.
name: Sutcliffe, W.
name: Suzuki, S. Y.
name: Svidras, H.
name: Takizawa, M.
name: Tamponi, U.
name: Tanida, K.
name: Taniguchi, N.
name: Tenchini, F.
name: Tiwary, R.
name: Tonelli, D.
name: Torassa, E.
name: Trabelsi, K.
name: Tsaklidis, I.
name: Ueda, I.
name: Uematsu, Y.
name: Uglov, T.
name: Unger, K.
name: Unno, Y.
name: Uno, K.
name: Uno, S.
name: Urquijo, P.
name: Ushiroda, Y.
name: Vahsen, S. E.
name: van Tonder, R.
name: Varner, G. S.
name: Varvell, K. E.
name: Vinokurova, A.
name: Vismaya, V. S.
name: Vitale, L.
name: Vossen, A.
name: Wallner, S.
name: Wang, E.
name: Wang, M. -Z.
name: Wang, X. L.
name: Warburton, A.
name: Watanabe, M.
name: Watanuki, S.
name: Welsch, M.
name: Wessel, C.
name: Won, E.
name: Xu, X. P.
name: Yabsley, B. D.
name: Yamada, S.
name: Yan, W.
name: Yang, S. B.
name: Ye, H.
name: Yin, J. H.
name: Yook, Y. M.
name: Yoshihara, K.
name: Zhai, Y.
name: Zhang, Y.
name: Zhilich, V.
name: Zhou, Q. D.
name: Zhou, X. Y.
name: Zhukova, V. I.
name: Žlebčík, R.
Publisher: name: arXiv
Year: 2023
Subjects: subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences
subject: FOS: Physical sciences

description: We present the first measurement of the ratio of branching fractions of inclusive semileptonic $B$-meson decays, $R(X_{e/μ}) = \mathcal{B}(B\to X \, e \, ν) / \mathcal{B}(B\to X \, μ\, ν)$, a precision test of electron-muon universality, using data corresponding to $189\,\mathrm{fb}^{-1}$ from electron-positron collisions collected with the Belle II detector. In events where the partner $B$ meson is fully reconstructed, we use fits to the lepton momentum spectra above $1.3\,\mathrm{GeV}/c$ to obtain $R(X_{e/μ}) = 1.007 \pm 0.009~(\mathrm{stat}) \pm 0.019~(\mathrm{syst})$, which is the most precise lepton-universality test of its kind and agrees with the standard-model expectation.