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. LiLibby, 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.Van Tonder, R.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.Zhulanov, V.2021-04-102021-04-102021-04-102021-03-1010.1007/JHEP03(2021)105https://infoscience.epfl.ch/handle/20.500.14299/177223WOS:000628215300001We 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.Physics, Particles & FieldsPhysicsfcnc interactionflavor physicsflavour changing neutral currentsb physicse(+)-e(-) experimentstext::journal::journal article::research article