Details

Autor(en) / Beteiligte

• Giri, A.
• Asner, D. M.
• Atmacan, H.
• Aulchenko, V.
• Ayad, R.
• Beleño, C.
• Biswal, J.
• Bonvicini, G.
• Bozek, A.
• Browder, T. E.
• Červenkov, D.
• Chang, M.-C.
• Chang, P.
• Chekelian, V.
• Choi, S.-K.
• Cinabro, D.
• Cunliffe, S.
• De Nardo, G.
• Dingfelder, J.
• Doležal, Z.
• Dong, T. V.
• Dossett, D.
• Dubey, S.
• Eidelman, S.
• Fulsom, B. G.
• Garg, R.
• Garmash, A.
• Goldenzweig, P.
• Golob, B.
• Hedges, M. T.
• Hou, W.-S.
• Hsu, C.-L.
• Joo, C. W.
• Joo, K. K.
• Kahn, J.
• Kaliyar, A. B.
• Kang, K. H.
• Karyan, G.
• Kichimi, H.
• Kiesling, C.
• Kim, K. T.
• Kodyš, P.
• Kotchetkov, D.
• Kuhr, T.
• Li, L. K.
• Libby, J.
• Lieret, K.
• Liventsev, D.
• Luo, T.
• Masuda, M.
• Matvienko, D.
• Merola, M.
• Mohanty, S.
• Natkaniec, Z.
• Nayak, L.
• Niiyama, M.
• Nisar, N. K.
• Ogawa, K.
• Ono, H.
• Onuki, Y.
• Oskin, P.
• Pakhlov, P.
• Park, H.
• Park, S.-H.
• Pedlar, T. K.
• Pestotnik, R.
• Podobnik, T.
• Prim, M. T.
• Rabusov, A.
• Rostomyan, A.
• Rout, N.
• Rozanska, M.
• Sanuki, T.
• Schnell, G.
• Schueler, J.
• Schwartz, A. J.
• Seino, Y.
• Senyo, K.
• Shapkin, M.
• Shwartz, B.
• Simon, F.
• Starič, M.
• Stottler, Z. S.
• Sumiyoshi, T.
• Takizawa, M.
• Tanida, K.
• Uchida, M.
• Urquijo, P.
• Ushiroda, Y.
• Vorobyev, V.
• Waheed, E.
• Wang, C. H.
• Watanuki, S.
• Wehle, S.
• Wiechczynski, J.
• Won, E.
• Yabsley, B. D.
• Yang, S. B.
• Yuan, C. Z.
• Zhang, Z. P.

Titel

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

Ist Teil von

• The journal of high energy physics, 2021-03, Vol.2021 (3), p.1-24, Article 105

Ort / Verlag

Berlin/Heidelberg: Springer Berlin Heidelberg

Erscheinungsjahr

2021

Link zum Volltext

Quelle

Electronic Journals Library

Beschreibungen/Notizen

• A bstract We present measurements of the branching fractions for the decays B → Kμ + μ − and B → Ke + e − , and their ratio ( R K ), using a data sample of 711 fb − 1 that contains 772 × 10 6 B B ¯ events. The data were collected at the ϒ(4 S ) resonance with the Belle detector at the KEKB asymmetric-energy e + e − collider. The ratio R K is measured in five bins of dilepton invariant-mass-squared ( q 2 ): q 2 ∈ (0 . 1 , 4 . 0) , (4 . 00 , 8 . 12) , (1 . 0 , 6 . 0), (10 . 2 , 12 . 8) and ( > 14 . 18) GeV 2 /c 4 , along with the whole q 2 region. The R K value for q 2 ∈ (1 . 0 , 6 . 0) GeV 2 /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 ∈ (1 . 0 , 6 . 0) GeV 2 /c 4 bin in the mode with muon final states. The measured differential branching fractions, d ℬ /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 → Kμ ± e ∓ decays and set 90% confidence-level upper limits on the branching fraction in the range of 10 − 8 for B + → K + μ ± e ∓ , and B 0 → K 0 μ ± e ∓ modes.