A search for the lepton-flavor-violating decays B-s(0) -> e(+/-)mu(-/+) and B-0 -> e(+/-)mu(-/+) is performed with a data sample, corresponding to an integrated luminosity of 1.0 fb(-1) of pp collisions at root s = 7 TeV, collected by the LHCb experiment. The observed number of B-s(0) -> e(+/-)mu(-/+) and B-0 -> e(+/-)mu(-/+) candidates is consistent with background expectations. Upper limits on the branching fractions of both decays are determined to be B(B-s(0) -> e(+/-)mu(-/+)) < 1.1(1.4) x 10(-8) and B(B-0 -> e(+/-)mu(-/+)) < 2.8(3.7) x 10(-9) at 90% (95%) confidence level (C.L.). These limits are a factor of 20 lower than those set by previous experiments. Lower bounds on the Pati-Salam leptoquark masses are also calculated, M-LQ(B-s(0) -> e(+/-)mu(-/+)) > 101 TeV/c(2) and M-LQ(B-0 -> e(+/-)mu -/+) > 126 TeV/c(2) at 95% C.L., and are a factor of 2 higher than the previous bounds.
Olivier Schneider, Yiming Li, Mingkui Wang, Chao Wang, Sun Hee Kim, Donghyun Kim, Xiao Wang, Lei Li
Jian Wang, Olivier Schneider, Yiming Li, Yi Zhang, Aurelio Bay, Guido Haefeli, Christoph Frei, Frédéric Blanc, Tatsuya Nakada, Michel De Cian, Luca Pescatore, François Fleuret, Elena Graverini, Chitsanu Khurewathanakul, Renato Quagliani, Federico Betti, Aravindhan Venkateswaran, Luis Miguel Garcia Martin, Vitalii Lisovskyi, Katharina Müller, Sebastian Schulte, Veronica Sølund Kirsebom, Elisabeth Maria Niel, Mingkui Wang, Zhirui Xu, Lei Zhang, Ho Ling Li, Mark Tobin, Minh Tâm Tran, Niko Neufeld, Matthew Needham, Marc-Olivier Bettler, Greig Alan Cowan, Maurizio Martinelli, Vladislav Balagura, Donal Patrick Hill, Liang Sun, Pietro Marino, Mirco Dorigo, Xiaoxue Han, Liupan An, Federico Leo Redi, Plamen Hristov Hopchev, Thibaud Humair, Maxime Schubiger, Hang Yin, Guido Andreassi, Violaine Bellée, Olivier Göran Girard, Axel Kuonen, Preema Rennee Pais, Pavol Stefko, Tara Nanut, Maria Elena Stramaglia, Yao Zhou, Tommaso Colombo, Vladimir Macko, Guillaume Max Pietrzyk, Evgenii Shmanin, Simone Meloni, Xiaoqing Zhou, Surapat Ek-In, Dipanwita Dutta, Zheng Wang, Yi Wang, Hans Dijkstra, Gerhard Raven, Peter Clarke, Frédéric Teubert, Giovanni Carboni, Victor Coco, Adam Davis, Paolo Durante, Wenyu Zhang, Yu Zheng, Anton Petrov, Maxim Borisyak, Feng Jiang, Zhipeng Tang, Xuan Li, Alexey Boldyrev, Almagul Kondybayeva, Hossein Afsharnia