Measurement of the Lepton Forward-Backward Asymmetry in $B \rightarrow X_s \ell^+ \ell^-$ Decays with a Sum of Exclusive Modes
Creators: name: Sato, Y.
name: Ishikawa, A.
name: Yamamoto, H.
name: Abdesselam, A.
name: Adachi, I.
name: Adamczyk, K.
name: Aihara, H.
name: Asner, D. M.
name: Aulchenko, V.
name: Aushev, T.
name: Ayad, R.
name: Bakich, A. M.
name: Bala, A.
name: Bhardwaj, V.
name: Bhuyan, B.
name: Bondar, A.
name: Bonvicini, G.
name: Bozek, A.
name: Bra\v, M.
name: Browder, T. E.
name: \v, D.
name: Chekelian, V.
name: Chen, A.
name: Cheon, B. G.
name: Cho, I. -S.
name: Cho, K.
name: Chobanova, V.
name: Choi, Y.
name: Cinabro, D.
name: Dalseno, J.
name: Danilov, M.
name: Dole\v, Z.
name: Drásal, Z.
name: Drutskoy, A.
name: Dutta, D.
name: Dutta, K.
name: Eidelman, S.
name: Farhat, H.
name: Fast, J. E.
name: Ferber, T.
name: Gaur, V.
name: Garmash, A.
name: Gillard, R.
name: Goh, Y. M.
name: Golob, B.
name: Haba, J.
name: Hara, T.
name: Hayasaka, K.
name: Hayashii, H.
name: He, X. H.
name: Hoshi, Y.
name: Hou, W. -S.
name: Hyun, H. J.
name: Iijima, T.
name: Itoh, R.
name: Iwasaki, Y.
name: Iwashita, T.
name: Jaegle, I.
name: Julius, T.
name: Kang, J. H.
name: Kato, E.
name: Kato, Y.
name: Kawai, H.
name: Kawasaki, T.
name: Kichimi, H.
name: Kim, D. Y.
name: Kim, H. J.
name: Kim, J. B.
name: Kim, J. H.
name: Kim, M. J.
name: Kim, Y. J.
name: Kinoshita, K.
name: Klucar, J.
name: Ko, B. R.
name: Kody\v, P.
name: Korpar, S.
name: Kri\v, P.
name: Krokovny, P.
name: Kuhr, T.
name: Kumita, T.
name: Kuzmin, A.
name: Kwon, Y. -J.
name: Lee, S. -H.
name: Li, Y.
name: Libby, J.
name: Liu, C.
name: Liu, Y.
name: Liu, Z. Q.
name: Liventsev, D.
name: Lukin, P.
name: Miyata, H.
name: Mizuk, R.
name: Mohanty, G. B.
name: Moll, A.
name: Mussa, R.
name: Nakao, M.
name: Natkaniec, Z.
name: Nayak, M.
name: Nedelkovska, E.
name: Nisar, N. K.
name: Nishida, S.
name: Nitoh, O.
name: Ogawa, S.
name: Pakhlov, P.
name: Park, H.
name: Park, H. K.
name: Pedlar, T. K.
name: Peng, T.
name: Pestotnik, R.
name: Petri\v, M.
name: Piilonen, L. E.
name: Ribe\v, E.
name: Ritter, M.
name: Röhrken, M.
name: Rostomyan, A.
name: Sahoo, H.
name: Saito, T.
name: Sakai, Y.
name: Sandilya, S.
name: Santel, D.
name: Santelj, L.
name: Sanuki, T.
name: Savinov, V.
name: Schneider, O.
name: Schnell, G.
name: Schwanda, C.
name: Schwartz, A. J.
name: Seidl, R.
name: Semmler, D.
name: Senyo, K.
name: Sevior, M. E.
name: Shapkin, M.
name: Shen, C. P.
name: Shibata, T. -A.
name: Shiu, J. -G.
name: Shwartz, B.
name: Sibidanov, A.
name: Simon, F.
name: Sohn, Y. -S.
name: Sokolov, A.
name: Solovieva, E.
name: Stani\v, S.
name: Stari\v, M.
name: Sumiyoshi, T.
name: Tamponi, U.
name: Tatishvili, G.
name: Teramoto, Y.
name: Trabelsi, K.
name: Uchida, M.
name: Uehara, S.
name: Uglov, T.
name: Unno, Y.
name: Uno, S.
name: Urquijo, P.
name: Ushiroda, Y.
name: Usov, Y.
name: Vahsen, S. E.
name: Van Hulse, C.
name: Vanhoefer, P.
name: Varner, G.
name: Varvell, K. E.
name: Vorobyev, V.
name: Wang, C. H.
name: Wang, M. -Z.
name: Wang, P.
name: Wang, X. L.
name: Watanabe, Y.
name: Won, E.
name: Yamaoka, J.
name: Yamashita, Y.
name: Yashchenko, S.
name: Yook, Y.
name: Zhang, Z. P.
name: Zhilich, V.
name: Zhulanov, V.
name: Zupanc, A.
Publisher: name: arXiv
Year: 2014
Subjects: subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences
subject: FOS: Physical sciences

description: We report the first measurement of the lepton forward-backward asymmetry ${\cal A}_{\rm FB}$ as a function of the squared four-momentum of the dilepton system, $q^2$, for the electroweak penguin process $B \rightarrow X_s \ell^+ \ell^-$ with a sum of exclusive final states, where $\ell$ is an electron or a muon and $X_s$ is a hadronic recoil system with an $s$ quark. The results are based on a data sample containing $772\times10^6$ $B\bar{B}$ pairs recorded at the $Υ(4S)$ resonance with the Belle detector at the KEKB $e^+ e^-$ collider. ${\cal A}_{\rm FB}$ for the inclusive $B \rightarrow X_s \ell^+ \ell^-$ is extrapolated from the sum of 10 exclusive $X_s$ states whose invariant mass is less than 2 GeV/$c^2$. For $q^2 &gt; 10.2$ GeV$^2$/$c^2$, ${\cal A}_{\rm FB} &lt; 0$ is excluded at the 2.3$σ$ level, where $σ$ is the standard deviation. For $q^2 &lt; 4.3$ GeV$^2$/$c^2$, the result is within 1.8$σ$ of the Standard Model theoretical expectation.
description: 13 pages, 23 figures, Belle Preprint 2014-1, KEK preprint 2013-60