Test of lepton flavor universality and search for lepton flavor violation in B -> Kll decays

Li, Y.; Li, Y. B.; Shen, C. P.; Adachi, I.; Aihara, H.; Asner, D. M.; Atmacan, H.; Aulchenko, V.; Ayad, R.; Babu, V.; Badhrees, I.; Bakich, A. M.; Behera, P.; Bilka, T.; Biswal, J.; Bobrov, A.; Bonvicini, G.; Bozek, A.; Bracko, M.; Browder, T. E.; Campajola, M.; Cao, L.; Cervenkov, D.; Chang, P.; Chen, A.; Cheon, B. G.; Chilikin, K.; Cho, H. E.; Cho, K.; Choi, S. -K.; Choi, Y.; Cinabro, D.; Cunliffe, S.; De Nardo, G.; Di Capua, F.; Di Carlo, S.; Dolezal, Z.; Dong, T. V.; Eidelman, S.; Fast, J. E.; Ferber, T.; Ferlewicz, D.; Fulsom, B. G.; Garg, R.; Gaur, V.; Gabyshev, N.; Garmash, A.; Giri, A.; Goldenzweig, P.; Golob, B.; Grube, B.; Hara, T.; Hayasaka, K.; Hayashii, H.; Hou, W. -S.; Hsu, C. -L.; Iijima, T.; Inami, K.; Inguglia, G.; Ishikawa, A.; Itoh, R.; Iwasaki, M.; Iwasaki, Y.; Jacobs, W. W.; Jia, S.; Jin, Y.; Joo, K. K.; Kang, K. H.; Karyan, G.; Kichimi, H.; Kim, C. H.; Kim, D. Y.; Kim, S. H.; Kinoshita, K.; Kodys, P.; Korpar, S.; Kroeger, R.; Krokovny, P.; Kuhr, T.; Kulasiri, R.; Kuzmin, A.; Kwon, Y. -J.; Lalwani, K.; Lange, J. S.; Lee, I. S.; Lee, S. C.; Lewis, P.; Li, C. H.; Li, L. K.; Gioi, L. Li; Libby, J.; Lieret, K.; Liventsev, D.; MacQueen, C.; Masuda, M.; Matsuda, T.; Matvienko, D.; Merola, M.; Miyata, H.; Mizuk, R.; Mussa, R.; Nakao, M.; Nath, K. J.; Nayak, M.; Niiyama, M.; Nisar, N. K.; Nishida, S.; Nishimura, K.; Ogawa, S.; Ono, H.; Onuki, Y.; Oskin, P.; Pakhlov, P.; Pakhlova, G.; Pang, T.; Pardi, S.; Park, H.; Park, S. -H.; Patra, S.; Paul, S.; Pedlar, T. K.; Pestotnik, R.; Piilonen, L. E.; Podobnik, T.; Popov, V.; Prencipe, E.; Prim, M. T.; Roehrken, M.; Rostomyan, A.; Rout, N.; Russo, G.; Sahoo, D.; Sakai, Y.; Sandilya, S.; Santelj, L.; Savinov, V.; Schneider, O.; Schnell, G.; Schwanda, C.; Seino, Y.; Senyo, K.; Sevior, M. E.; Shiu, J. -G.; Shwartz, B.; Sokolov, A.; Solovieva, E.; Stanic, S.; Staric, M.; Stottler, Z. S.; Sumihama, M.; Sumiyoshi, T.; Sutcliffe, W.; Takizawa, M.; Tanida, K.; Tenchini, F.; Trabelsi, K.; Uchida, M.; Uglov, T.; Unno, Y.; Uno, S.; Tonder, R. van; Varner, G.; Vinokurova, A.; Wang, C. H.; Wang, M. -Z.; Wang, X. L.; Watanabe, M.; Won, E.; Yang, S. B.; Ye, H.; Yelton, J.; Yin, J. H.; Yuan, C. Z.; Zhang, Z. P.; Zhilich, V.; Zhukova, V. und Zhulanov, V. (2021): Test of lepton flavor universality and search for lepton flavor violation in B -> Kll decays. In: Journal of High Energy Physics, Nr. 3, 105

Abstract

We present measurements of the branching fractions for the decays B -> K mu(+)mu(-) and B -> Ke(+)e(-), and their ratio (R-K), using a data sample of 711 fb(-1) that contains 772 x 10(6) B (B) over bar events. The data were collected at the Gamma(4S) resonance with the Belle detector at the KEKB asymmetric-energy e(+)e(-) collider. The ratio RK is measured in five bins of dilepton invariant-mass-squared (q(2)): q(2) is an element of (0.1, 4.0), (4.00, 8.12), (1.0, 6.0), (10.2, 12.8) and (> 14.18) GeV2/c(4), along with the whole q(2) region. The R-K value for q(2) is an element of (1.0, 6.0) GeV2/c(4) is 1.03(-0.24)(+0.28) +/- 0.01. The first and second uncertainties listed are statistical and systematic, respectively. All results for R-K are consistent with Standard Model predictions. We also measure CP-averaged isospin asymmetries in the same q(2) bins. The results are consistent with a null asymmetry, with the largest difference of 2.6 standard deviations occurring for the q(2) is an element of (1.0, 6.0) GeV2/c(4) bin in the mode with muon final states. The measured differential branching fractions, dB/dq(2), are consistent with theoretical predictions for charged B decays, while the corresponding values are below the expectations for neutral B decays. We have also searched for lepton-flavor-violating B -> K mu(+/-)e(-/+) decays and set 90% confidence-level upper limits on the branching fraction in the range of 10(-8) for B+ -> K+ mu(+/-)e(-/+), and B-0 -> K-0 mu(+/-) e(-/+) modes.

• Dokumententyp: Zeitschriftenartikel
• Fakultät: Physik
• Themengebiete: 500 Naturwissenschaften und Mathematik > 530 Physik
• ISSN: 1029-8479
• Sprache: Englisch