Measurement of the decays $B\to \eta \ell {\nu }_{\ell }$ and $B\to {\eta }^{\text{'}}\ell {\nu }_{\ell }$ in fully reconstructed events at Belle

Journal Article · 28 November 2017 · Physical Review D

DOI: https://doi.org/10.1103/PhysRevD.96.091102 · OSTI ID:1594348

Beleño, C.; Dingfelder, J.; Urquijo, P.; Aihara, H.; Al Said, S.; Asner, D. M.; Aushev, T.; Ayad, R.; Babu, V.; Badhrees, I.; Bakich, A. M.; Bansal, V.; Behera, P.; Bhuyan, B.; Biswal, J.; Bobrov, A.; Bračko, M.; Browder, T. E.; Červenkov, D.; Chen, A. ; Cheon, B. G.; Chistov, R.; Cho, K.; Choi, S. -K.; Choi, Y.; Cinabro, D.; Dash, N.; Di Carlo, S.; Doležal, Z.; Eidelman, S.; Farhat, H.; Fast, J. E.; Ferber, T.; Frey, A.; Fulsom, B. G.; Gaur, V.; Gabyshev, N.; Garmash, A.; Gillard, R.; Goldenzweig, P.; Hara, T.; Hayashii, H.; Hedges, M. T.; Hou, W. -S.; Iijima, T.; Inami, K.; Inguglia, G.; Ishikawa, A.; Itoh, R.; Iwasaki, Y.; Jeon, H. B.; Jin, Y.; Joffe, D.; Joo, K. K.; Kang, K. H.; Karyan, G.; Kim, D. Y.; Kim, J. B.; Kim, K. T.; Kim, M. J.; Kim, Y. J.; Kinoshita, K.; Kodyš, P.; Korpar, S.; Kotchetkov, D.; Križan, P.; Krokovny, P.; Kulasiri, R.; Lee, I. S.; Li, Y.; Li Gioi, L.; Libby, J.; Liventsev, D.; Lubej, M.; Luo, T.; Masuda, M.; Matsuda, T.; Matvienko, D.; Miyabayashi, K.; Miyata, H.; Moon, H. K.; Mori, T.; Nakano, E.; Nakao, M.; Nanut, T.; Nath, K. J.; Nayak, M.; Nishida, S.; Ogawa, S.; Okuno, S.; Ono, H.; Pal, B.; Park, C. -S.; Park, C. W.; Park, H.; Pedlar, T. K.; Pestotnik, R.; Piilonen, L. E.; Ritter, M.; Sakai, Y.; Salehi, M.; Sandilya, S.; Sanuki, T.; Schneider, O.; Schnell, G.; Schwanda, C.; Seino, Y.; Senyo, K.; Seon, O.; Sevior, M. E.; Shebalin, V.; Shibata, T. -A.; Shiu, J. -G.; Simon, F.; Solovieva, E.; Starič, M.; Sumiyoshi, T.; Takizawa, M.; Tamponi, U.; Tanida, K.; Tenchini, F.; Uchida, M.; Uglov, T.; Unno, Y.; Uno, S.; Usov, Y.; Van Hulse, C.; Varner, G.; Varvell, K. E.; Vinokurova, A.; Vorobyev, V.; Wang, C. H.; Wang, M. -Z.; Wang, P.; Watanabe, Y.; Widmann, E.; Won, E.; Yamashita, Y.; Ye, H.; Yelton, J.; Yook, Y.; Zhang, Z. P.; Zhilich, V.; Zhukova, V.; Zhulanov, V.; Zupanc, A.

We report branching fraction measurements of the decays B⁺ → ηℓ⁺νℓ and B⁺ → η'ℓ⁺νℓ based on 711 fb^–1 of data collected near the Υ(4S) resonance with the Belle experiment at the KEKB asymmetric-energy e⁺e^– collider. This data sample contains 772 million BB¯ 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 η meson in two decay channels, η → γγ and η → π⁺π^–π⁰, and reconstruct the η' meson in η' → ηπ⁺π^– with subsequent decay of the η into γγ. Combining the two η modes and using an extended maximum likelihood, the B⁺ → ηℓ⁺νℓ branching fraction is measured to be (4.2 ± 1.1(stat.) ± 0.3(syst.)) × 10^–5. For B⁺ → η'ℓ⁺νℓ, we observe no significant signal and set an upper limit of 0.72 × 10^–4 at 90% confidence level.

• Research Organization: Virginia Polytechnic Inst. and State Univ. (Virginia Tech), Blacksburg, VA (United States)
• Sponsoring Organization: USDOE Office of Science (SC), High Energy Physics (HEP)
• Contributing Organization: Belle Collaboration
• Grant/Contract Number: SC0009973
• OSTI ID: 1594348
• Alternate ID(s): OSTI ID: 1410482
• Journal Information: Physical Review D, Vol. 96, Issue 9; ISSN 2470-0010
• Publisher: American Physical Society (APS)Copyright Statement
• Country of Publication: United States
• Language: English