Measurement of the Decays $\boldsymbol{B\to\eta\ell\nu_\ell}$ and $\boldsymbol{B\to\eta^\prime\ell\nu_\ell}$ in Fully Reconstructed Events at Belle
Creators: name: Beleño, C.
name: Dingfelder, J.
name: Urquijo, P.
name: Aihara, H.
name: Al Said, S.
name: Asner, D. M.
name: Aushev, T.
name: Ayad, R.
name: Babu, V.
name: Badhrees, I.
name: Bakich, A. M.
name: Bansal, V.
name: Behera, P.
name: Bhuyan, B.
name: Biswal, J.
name: Bobrov, A.
name: Bračko, M.
name: Browder, T. E.
name: Červenkov, D.
name: Chen, A.
name: Cheon, B. G.
name: Chistov, R.
name: Cho, K.
name: Choi, S.-K.
name: Choi, Y.
name: Cinabro, D.
name: Dash, N.
name: Di Carlo, S.
name: Doležal, Z.
name: Eidelman, S.
name: Farhat, H.
name: Fast, J. E.
name: Ferber, T.
name: Frey, A.
name: Fulsom, B. G.
name: Gaur, V.
name: Gabyshev, N.
name: Garmash, A.
name: Gillard, R.
name: Goldenzweig, P.
name: Hara, T.
name: Hayashii, H.
name: Hedges, M. T.
name: Hou, W.-S.
name: Iijima, T.
name: Inami, K.
name: Inguglia, G.
name: Ishikawa, A.
name: Itoh, R.
name: Iwasaki, Y.
name: Jeon, H. B.
name: Jin, Y.
name: Joffe, D.
name: Joo, K. K.
name: Kang, K. H.
name: Karyan, G.
name: Kim, D. Y.
name: Kim, J. B.
name: Kim, K. T.
name: Kim, M. J.
name: Kim, Y. J.
name: Kinoshita, K.
name: Kodyš, P.
name: Korpar, S.
name: Kotchetkov, D.
name: Križan, P.
name: Kulasiri, R.
name: Lee, I. S.
name: Li, Y.
name: Li Gioi, L.
name: Libby, J.
name: Liventsev, D.
name: Lubej, M.
name: Luo, T.
name: Masuda, M.
name: Matsuda, T.
name: Matvienko, D.
name: Miyabayashi, K.
name: Miyata, H.
name: Moon, H. K.
name: Mori, T.
name: Nakano, E.
name: Nakao, M.
name: Nanut, T.
name: Nath, K. J.
name: Nayak, M.
name: Nishida, S.
name: Ogawa, S.
name: Okuno, S.
name: Ono, H.
name: Pal, B.
name: Park, C.-S.
name: Park, C. W.
name: Park, H.
name: Pedlar, T. K.
name: Pestotnik, R.
name: Piilonen, L. E.
name: Ritter, M.
name: Sakai, Y.
name: Salehi, M.
name: Sandilya, S.
name: Sanuki, T.
name: Schneider, O.
name: Schnell, G.
name: Schwanda, C.
name: Seino, Y.
name: Senyo, K.
name: Seon, O.
name: Sevior, M. E.
name: Shebalin, V.
name: Shibata, T.-A.
name: Shiu, J.-G.
name: Simon, F.
name: Solovieva, E.
name: Starič, M.
name: Sumiyoshi, T.
name: Takizawa, M.
name: Tamponi, U.
name: Tanida, K.
name: Tenchini, F.
name: Uchida, M.
name: Uglov, T.
name: Unno, Y.
name: Uno, S.
name: Usov, Y.
name: Van Hulse, C.
name: Varner, G.
name: Varvell, K. E.
name: Vinokurova, A.
name: Vorobyev, V.
name: Wang, C. H.
name: Wang, M.-Z.
name: Wang, P.
name: Watanabe, Y.
name: Widmann, E.
name: Won, E.
name: Yamashita, Y.
name: Ye, Hua
name: Yelton, J.
name: Yook, Y.
name: Zhang, Z. P.
name: Zhilich, V.
name: Zhukova, V.
name: Zhulanov, V.
name: Zupanc, A.
Publisher: name: Deutsches Elektronen-Synchrotron, DESY, Hamburg
Year: 2017
Subjects: electron positron: annihilation
electron positron: colliding beams
B: pair production
B+: semileptonic decay
B+: branching ratio: measured
B+: branching ratio: upper limit
photon: pair production
eta: radiative decay
pi: multiple production
eta(958): hadronic decay
eta: hadronic decay
BELLE
B: hadronic decay
Upsilon(10570): electroproduction
decay modes
KEK-B
experimental results
B+ --&gt; eta lepton+ neutrino
B+ --&gt; eta(958) lepton+ neutrino
eta(958) --&gt; eta pi+ pi-
eta --&gt; 2photon
eta --&gt; pi+ pi- pi0
10.570 GeV-cms

description: We report branching fraction measurements of the decays $B^+\to\eta\ell^+\nu_\ell$ and $B^+\to\eta^\prime\ell^+\nu_\ell$ based on 711~fb$^{-1}$ of data collected near the $\Upsilon(4S)$ resonance with the Belle experiment at the KEKB asymmetric-energy $e^+e^-$ collider. This data sample contains 772 million $B\bar B$~events. One of the two $B$~mesons is fully reconstructed in a hadronic decay mode. Among the remaining ('signal-$B$') daughters, we search for the $\eta$~meson in two decay channels, $\eta\to\gamma\gamma$ and $\eta\to\pi^+\pi^-\pi^0$, and reconstruct the $\eta^{\prime}$~meson in $\eta^\prime\to\eta\pi^+\pi^-$ with subsequent decay of the $\eta$ into $\gamma\gamma$. Combining the two $\eta$ modes and using an extended maximum likelihood, the $B^+\to\eta\ell^+\nu_\ell$ branching fraction is measured to be $(4.2\pm 1.1 (\rm stat.)\pm 0.3 (\rm syst.))\times 10^{-5}$. For $B^+\to\eta^\prime\ell^+\nu_\ell$, we observe no significant signal and set an upper limit of $0.72\times 10^{-4}$ at 90\% confidence level.