Measurements of branching fractions and q2 distributions for B → π ℓ ν and B → ρ ℓ ν decays with B → D(*) ℓ ν decay tagging

T. Hokuue, K. Abe, K. Abe, I. Adachi, H. Aihara, Y. Asano, T. Aushev, A. M. Bakich, V. Balagura, E. Barberio, M. Barbero, A. Bay, I. Bedny, K. Belous, U. Bitenc, I. Bizjak, S. Blyth, A. Bondar, A. Bozek, M. BračkoT. E. Browder, P. Chang, A. Chen, W. T. Chen, Y. Choi, A. Chuvikov, S. Cole, J. Dalseno, M. Danilov, M. Dash, A. Drutskoy, S. Eidelman, N. Gabyshev, A. Garmash, T. Gershon, G. Gokhroo, A. Gorišek, H. Ha, J. Haba, K. Hara, T. Hara, K. Hayasaka, H. Hayashii, M. Hazumi, L. Hinz, Y. Hoshi, S. Hou, W. S. Hou, T. Iijima, K. Ikado, A. Imoto, K. Inami, A. Ishikawa, R. Itoh, M. Iwasaki, Y. Iwasaki, H. Kakuno, J. H. Kang, P. Kapusta, S. U. Kataoka, H. Kawai, T. Kawasaki, H. R. Khan, H. J. Kim, H. O. Kim, K. Kinoshita, Y. Kozakai, P. Križan, P. Krokovny, R. Kulasiri, R. Kumar, C. C. Kuo, A. Kuzmin, Y. J. Kwon, J. Lee, T. Lesiak, J. Li, A. Limosani, S. W. Lin, G. Majumder, F. Mandl, T. Matsumoto, A. Matyja, S. McOnie, W. Mitaroff, H. Miyake, H. Miyata, Y. Miyazaki, D. Mohapatra, I. Nakamura, E. Nakano, Z. Natkaniec, S. Nishida, O. Nitoh, T. Nozaki, S. Ogawa, T. Ohshima, T. Okabe, S. Okuno, S. L. Olsen, Y. Onuki, P. Pakhlov, C. W. Park, H. Park, L. S. Peak, R. Pestotnik, L. E. Piilonen, Y. Sakai, N. Sato, N. Satoyama, K. Sayeed, T. Schietinger, O. Schneider, C. Schwanda, A. J. Schwartz, K. Senyo, M. E. Sevior, M. Shapkin, H. Shibuya, B. Shwartz, A. Somov, R. Stamen, S. Stanič, M. Starič, H. Stoeck, A. Sugiyama, S. Suzuki, S. Y. Suzuki, O. Tajima, F. Takasaki, K. Tamai, M. Tanaka, G. N. Taylor, Y. Teramoto, X. C. Tian, T. Tsukamoto, K. Ueno, T. Uglov, Y. Unno, S. Uno, P. Urquijo, Y. Usov, G. Varner, K. E. Varvell, S. Villa, C. C. Wang, C. H. Wang, M. Z. Wang, Y. Watanabe, E. Won, A. Yamaguchi, Y. Yamashita, M. Yamauchi, J. Ying, L. M. Zhang, Z. P. Zhang, D. Zürcher

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63 Citations (Scopus)


We report measurements of the charmless semileptonic decays B0 → π- / ρ-+ ν and B+ → π0 / ρ0+ ν, based on a sample of 2.75 × 108B over(B, ̄) events collected at the Υ{hooked} (4 S) resonance with the Belle detector at the KEKB e+ e- asymmetric collider. In this analysis, the accompanying B meson is reconstructed in the semileptonic mode B → D(*) ℓ ν, enabling detection of the signal modes with high purity. We measure the branching fractions B (B0 → π-+ ν) = (1.38 ± 0.19 ± 0.14 ± 0.03) × 10-4, B (B0 → ρ-+ ν) = (2.17 ± 0.54 ± 0.31 ± 0.08) × 10-4, B (B+ → π0+ ν) = (0.77 ± 0.14 ± 0.08 ± 0.00) × 10-4 and B (B+ → ρ0+ ν) = (1.33 ± 0.23 ± 0.17 ± 0.05) × 10-4, where the errors are statistical, experimental systematic, and systematic due to form factor uncertainties, respectively. For each mode we also present the partial branching fractions in three q2 intervals: q2 < 8, 8 ≤ q2 < 16, and q2 ≥ 16   GeV2 / c2. From our partial branching fractions for B → π ℓ ν and recent results for the form factor from unquenched Lattice QCD calculations, we obtain values of the CKM matrix element | Vu b |.

Original languageEnglish
Pages (from-to)139-148
Number of pages10
JournalPhysics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics
Issue number2-3
Publication statusPublished - 2007 May 3

Bibliographical note

Funding Information:
We thank the KEKB group for the excellent operation of the accelerator, the KEK cryogenics group for the efficient operation of the solenoid, and the KEK computer group and the National Institute of Informatics for valuable computing and Super-SINET network support. We acknowledge support from the Ministry of Education, Culture, Sports, Science, and Technology of Japan and the Japan Society for the Promotion of Science; the Australian Research Council and the Australian Department of Education, Science and Training; the National Science Foundation of China and the Knowledge Innovation Program of Chinese Academy of Sciences under contract No. 10575109 and IHEP-U-503; the Department of Science and Technology of India; the BK21 program of the Ministry of Education of Korea, and the CHEP SRC program and Basic Research program (grant No. R01-2005-000-10089-0) of the Korea Science and Engineering Foundation; the Polish State Committee for Scientific Research under contract No. 2P03B 01324; the Ministry of Science and Technology of the Russian Federation; the Slovenian Research Agency; the Swiss National Science Foundation; the National Science Council and the Ministry of Education of Taiwan; and the US Department of Energy.


  • B decay
  • Exclusive
  • Semileptonic

ASJC Scopus subject areas

  • Nuclear and High Energy Physics


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