학술논문

First observation of $B\!\to \bar{D}_1(\to\bar{D}\pi^+\pi^-)\ell^+\nu_\ell$ and measurement of the $B\!\to \bar{D}^{(*)}\pi\ell^+\nu_\ell$ and $B\!\to \bar{D}^{(*)}\pi^+\pi^-\ell^+\nu_\ell$ branching fractions with hadronic tagging at Belle
Document Type
Working Paper
Author
Belle CollaborationMeier, F.Vossen, A.Adachi, I.Adamczyk, K.Aihara, H.Said, S. AlAsner, D. M.Atmacan, H.Aushev, T.Ayad, R.Babu, V.Bahinipati, S.Banerjee, Sw.Bauer, M.Behera, P.Belous, K.Bennett, J.Bernlochner, F.Bessner, M.Bhuyan, B.Bilka, T.Biswas, D.Bobrov, A.Bodrov, D.Bonvicini, G.Borah, J.Bozek, A.Bračko, M.Branchini, P.Browder, T. E.Budano, A.Campajola, M.Cao, L.Červenkov, D.Chang, M. -C.Chang, P.Chen, A.Cheon, B. G.Chilikin, K.Cho, K.Cho, S. -J.Choi, S. -K.Choi, Y.Choudhury, S.Cinabro, D.Das, S.De Nardo, G.De Pietro, G.Dhamija, R.Di Capua, F.Dingfelder, J.Doležal, Z.Dong, T. V.Epifanov, D.Ferber, T.Ferlewicz, D.Fulsom, B. G.Garg, R.Gaur, V.Giri, A.Goldenzweig, P.Golob, B.Graziani, E.Gudkova, K.Hadjivasiliou, C.Halder, S.Hara, T.Hayasaka, K.Hayashii, H.Hedges, M. T.Hou, W. -S.Hsu, C. -L.Inami, K.Ipsita, N.Ishikawa, A.Itoh, R.Iwasaki, M.Jacobs, W. W.Jang, E. -J.Jin, Y.Kaliyar, A. B.Kang, K. H.Kawasaki, T.Kiesling, C.Kim, C. H.Kim, D. Y.Kim, K. -H.Kim, Y. -K.Kinoshita, K.Kodyš, P.Korobov, A.Korpar, S.Kovalenko, E.Križan, P.Kroeger, R.Krokovny, P.Kuhr, T.Kumar, M.Kumar, R.Kumara, K.Kwon, Y. -J.Lam, T.Lange, J. S.Lee, S. C.Lewis, P.Li, C. H.Li, L. K.Li, Y.Li, Y. B.Gioi, L. LiLibby, J.Lieret, K.Lin, Y. -R.Liventsev, D.Luo, T.Masuda, M.Matsuda, T.Matvienko, D.Maurya, S. K.Merola, M.Metzner, F.Miyabayashi, K.Mizuk, R.Mussa, R.Nakamura, I.Nakao, M.Natkaniec, Z.Natochii, A.Nayak, L.Nayak, M.Nisar, N. K.Nishida, S.Ogawa, S.Ono, H.Oskin, P.Pakhlov, P.Pakhlova, G.Pardi, S.Park, H.Park, J.Passeri, A.Patra, S.Paul, S.Pestotnik, R.Piilonen, L. E.Podobnik, T.Prencipe, E.Prim, M. T.Rostomyan, A.Rout, N.Russo, G.Sandilya, S.Santelj, L.Savinov, V.Schnell, G.Schwanda, C.Schwartz, A. J.Seino, Y.Senyo, K.Sevior, M. E.Shapkin, M.Sharma, C.Shen, C. P.Shiu, J. -G.Simon, F.Singh, J. B.Soffer, A.Solovieva, E.Starič, M.Stottler, Z. S.Strube, J. F.Sumihama, M.Sumiyoshi, T.Takizawa, M.Tamponi, U.Tanida, K.Tenchini, F.Trabelsi, K.Uchida, M.Uglov, T.Unno, Y.Uno, K.Uno, S.Urquijo, P.Vahsen, S. E.Van Tonder, R.Varner, G.Varvell, K. E.Vinokurova, A.Wang, M. -Z.Watanabe, M.Watanuki, S.Wiechczynski, J.Won, E.Xu, X.Yabsley, B. D.Yan, W.Yang, S. B.Yin, J. H.Yuan, C. Z.Yuan, L.Yusa, Y.Zhang, Z. P.Zhukova, V.
Source
Phys. Rev. D 107, 092003 (2023)
Subject
High Energy Physics - Experiment
Language
Abstract
We report measurements of the ratios of branching fractions for $B \to \bar{D}^{(*)}\pi\ell^+\nu_\ell$ and $B \to \bar{D}^{(*)}\pi^+\pi^-\ell^+\nu_\ell$ relative to $B \to \bar{D}^*\ell^+\nu_\ell$ decays with $\ell = e, \mu$. These results are obtained from a data sample that contains $772 \times 10^6 B\bar{B}$ pairs collected near the $\Upsilon(4S)$ resonance with the Belle detector at the KEKB asymmetric energy $e^+e^-$ collider. Fully reconstructing both $B$ mesons in the event, we obtain \begin{align*} \frac{B(B^0 \to \bar{D}^0\pi^-\ell^+\nu_\ell)}{B(B^0 \to D^{*-}\ell^+\nu_\ell)} &= (7.24\pm0.36\pm0.12)\%\ ,\\ \frac{B(B^+ \to D^-\pi^+\ell^+\nu_\ell)}{B(B^+ \to \bar{D}^{*0}\ell^+\nu_\ell)} &= (6.78\pm0.24\pm0.15)\%\ ,\\ \frac{B(B^0 \to \bar{D}^{*0}\pi^-\ell^+\nu_\ell)}{B(B^0 \to D^{*-}\ell^+\nu_\ell)} &= (11.10\pm0.48\pm0.20)\%\ ,\\ \frac{B(B^+ \to D^{*-}\pi^+\ell^+\nu_\ell)}{B(B^+ \to \bar{D}^{*0}\ell^+\nu_\ell)} &= (9.50\pm0.33\pm0.27)\%\ ,\\ \frac{B(B^0 \to D^-\pi^+\pi^-\ell^+\nu_\ell)}{B(B^0 \to D^{*-}\ell^+\nu_\ell)} &= (2.91\pm0.37\pm0.25)\%\ ,\\ \frac{B(B^+ \to \bar{D}^0\pi^+\pi^-\ell^+\nu_\ell)}{B(B^+ \to \bar{D}^{*0}\ell^+\nu_\ell)} &= (3.10\pm0.26\pm0.21)\%\ ,\\ \frac{B(B^0 \to D^{*-}\pi^+\pi^-\ell^+\nu_\ell)}{B(B^0 \to D^{*-}\ell^+\nu_\ell)} &= (1.03\pm0.43\pm0.18)\%\ ,\\ \frac{B(B^+ \to \bar{D}^{*0}\pi^+\pi^-\ell^+\nu_\ell)}{B(B^+ \to \bar{D}^{*0}\ell^+\nu_\ell)} &= (1.25\pm0.27\pm0.15)\%\ , \end{align*} where the uncertainties are statistical and systematic, respectively. The invariant mass spectra of the $D\pi$, $D^*\pi$, and $D\pi\pi$ systems are studied. Branching fraction products are extracted, among them the first observations of $B(B^0 \to D_1^-\ell^+\nu_\ell) \times B(D_1^- \to D^-\pi^+\pi^-) = (0.102\pm0.013\pm0.009)\%$ and $B(B^+ \to \bar{D}_1^0\ell^+\nu_\ell) \times B(\bar{D}_1^0 \to \bar{D}^0\pi^+\pi^-) = (0.105\pm0.011\pm0.008)\%$.
Comment: submitted to Phys. Rev. D