학술논문
Measurement of the Branching Fraction of the Decay $\boldsymbol{B^{+}\to\pi^{+}\pi^{-}\ell^{+}\nu_\ell}$ in Fully Reconstructed Events at Belle
Document Type
Working Paper
Author
The Belle Collaboration; Beleño, C.; Frey, A.; Adachi, I.; Aihara, H.; Asner, D. M.; Atmacan, H.; Aushev, T.; Ayad, R.; Behera, P.; Bennett, J.; Bernlochner, F.; Bhardwaj, V.; Bilka, T.; Biswal, J.; Bonvicini, G.; Bozek, A.; Bračko, M.; Browder, T. E.; Campajola, M.; Červenkov, D.; Chang, P.; Chen, A.; Chilikin, K.; Cho, K.; Choi, Y.; Cinabro, D.; Cunliffe, S.; Dash, N.; Di Capua, F.; Dingfelder, J.; Doležal, Z.; Dong, T. V.; Eidelman, S.; Epifanov, D.; Fast, J. E.; Ferber, T.; Fulsom, B. G.; Garg, R.; Gaur, V.; Gabyshev, N.; Garmash, A.; Giri, A.; Goldenzweig, P.; Guan, Y.; Hartbrich, O.; Hayasaka, K.; Hayashii, H.; Hou, W. -S.; Inami, K.; Ishikawa, A.; Iwasaki, M.; Jacobs, W. W.; Jeon, H. B.; Jin, Y.; Joo, K. K.; Kiesling, C.; Kim, B. H.; Kim, D. Y.; Kim, K. -H.; Kim, S. H.; Kim, Y. -K.; Kimmel, T. D.; Kinoshita, K.; Kodyš, P.; Korpar, S.; Kotchetkov, D.; Križan, P.; Kroeger, R.; Krokovny, P.; Kuhr, T.; Kulasiri, R.; Kumar, R.; Kuzmin, A.; Kwon, Y. -J.; Lalwani, K.; Lee, S. C.; Li, L. K.; Li, Y. B.; Gioi, L. Li; Libby, J.; Lieret, K.; Liventsev, D.; Luo, T.; MacNaughton, J.; MacQueen, C.; Masuda, M.; Matsuda, T.; Merola, M.; Miyabayashi, K.; Mohanty, G. B.; Moon, T. J.; Mori, T.; Mrvar, M.; Nakao, M.; Nisar, N. K.; Nishida, S.; Ogawa, S.; Ono, H.; Oskin, P.; Pakhlov, P.; Pakhlova, G.; Pardi, S.; Park, H.; Patra, S.; Pedlar, T. K.; Pestotnik, R.; Piilonen, L. E.; Podobnik, T.; Prencipe, E.; Prim, M. T.; Rostomyan, A.; Rout, N.; Russo, G.; Sahoo, D.; Sakai, Y.; Sandilya, S.; Sangal, A.; Sanuki, T.; Savinov, V.; Schnell, G.; Schwanda, C.; Schwartz, A. J.; Schwenker, B.; Seino, Y.; Senyo, K.; Sevior, M. E.; Shapkin, M.; Shiu, J. -G.; Shwartz, B.; Sokolov, A.; Solovieva, E.; Starič, M.; Stottler, Z. S.; Strube, J. F.; Sumiyoshi, T.; Sutcliffe, W.; Takizawa, M.; Tanida, K.; Tenchini, F.; Uchida, M.; Uglov, T.; Uno, S.; Urquijo, P.; Vahsen, S. E.; Van Tonder, R.; Varner, G.; Varvell, K. E.; Wang, C. H.; Wang, E.; Wang, M. -Z.; Wang, P.; Wang, X. L.; Watanabe, M.; Won, E.; Xu, X.; Yan, W.; Yang, S. B.; Ye, H.; Yusa, Y.; Zhang, Z. P.; Zhilich, V.; Zhukova, V.
Source
Phys. Rev. D 103, 112001 (2021)
Subject
Language
Abstract
We present an analysis of the exclusive $B^{+}\to\pi^{+}\pi^{-}\ell^{+}\nu_{\ell}$ decay, where $\ell$ represents an electron or a muon, with the assumption of charge-conjugation symmetry and lepton universality. The analysis uses the full $\Upsilon(4S)$ data sample collected by the Belle detector, corresponding to 711 fb$^{-1}$ of integrated luminosity. We select the events by fully reconstructing one $B$ meson in hadronic decay modes, subsequently determining the properties of the other $B$ meson. We extract the signal yields using a binned maximum-likelihood fit to the missing-mass squared distribution in bins of the invariant mass of the two pions or the momentum transfer squared. We measure a total branching fraction of ${{\cal B}(B^{+}\to \pi^{+}\pi^{-}\ell^{+}\nu_{\ell})= [22.7 ^{+1.9}_{-1.6} (\mathrm{stat}) \pm 3.5(\mathrm{syst}) ]\times 10^{-5}}$, where the uncertainties are statistical and systematic, respectively. This result is the first reported measurement of this decay.
Comment: 23 pages, 19 figures
Comment: 23 pages, 19 figures