We study transitions between Υ states with the emission of charged pions using 604.6fb-1 of data collected with the Belle detector at the KEKB asymmetric-energy e+e- collider. The measured product branching fraction is B(Υ(4S)→Υ(1S)π+π-)×B(Υ(1S)→μ+μ-)=(2. 11±0.30(stat)±0.14(sys))×10-6 and the partial decay width is Γ(Υ(4S)→Υ(1S)π+π-)=(1.75±0.25(stat)±0. 24(sys))keV. © 2009 The American Physical Society.
Olivier Schneider, Aurelio Bay, Guido Haefeli, Tatsuya Nakada, Frédéric Blanc, Lesya Shchutska, Elena Graverini, Sebastian Schulte, Marie Theres Christin Bachmayer, Serhii Cholak, Ettore Zaffaroni, Aravindhan Venkateswaran, Luis Miguel Garcia Martin, Yunxuan Song, Vitalii Lisovskyi, Sonia Amina Bouchiba, Federico Ronchetti, Radoslav Marchevski, Anni Matilda Kauniskangas, Dimitrios Kaminaris, Raphaël van Laak, Pierre Paul Louis Mayencourt, Andrea Merli, Gianluca Zunica, Abdul-Kerim Guseinov, Roberto Ribatti, Spencer Edward Collaviti
Olivier Schneider, Aurelio Bay, Guido Haefeli, Tatsuya Nakada, Frédéric Blanc, Lesya Shchutska, Elena Graverini, Marie Theres Christin Bachmayer, Ettore Zaffaroni, Aravindhan Venkateswaran, Yunxuan Song, Vitalii Lisovskyi, Federico Ronchetti, Radoslav Marchevski, Anni Matilda Kauniskangas, Dimitrios Kaminaris, Raphaël van Laak, Pierre Paul Louis Mayencourt, Brianna Leililani Thielen, Arnaud Merlin Gauthey, Gianluca Zunica, Abdul-Kerim Guseinov, Roberto Ribatti, Louis André Marie Jean Henry, Spencer Edward Collaviti, Julius Christian Daniel Schulte