Measurement of CP Violation in B-0 -> D+D- Decays

Liupan An, Guido Andreassi, Aurelio Bay, Violaine Bellée, Federico Betti, Marc-Olivier Bettler, Frédéric Blanc, Maxim Borisyak, Peter Clarke, Victor Coco, Greig Alan Cowan, Adam Davis, Michel De Cian, Hans Dijkstra, Mirco Dorigo, Paolo Durante, François Fleuret, Christoph Frei, Sebastiana Gianì, Olivier Göran Girard, Elena Graverini, Guido Haefeli, Xiaoxue Han, Thibaud Humair, Chitsanu Khurewathanakul, Ilya Komarov, Axel Kuonen, Yiming Li, Pietro Marino, Maurizio Martinelli, Tatsuya Nakada, Matthew Needham, Niko Neufeld, Preema Rennee Pais, Luca Pescatore, Anton Petrov, Cédric Potterat, Jessica Prisciandaro, Renato Quagliani, Gerhard Raven, Federico Leo Redi, Olivier Schneider, Maxime Schubiger, Pavol Stefko, Liang Sun, Frédéric Teubert, Mark Tobin, Minh Tâm Tran, Maria Vieites Diaz, Jian Wang, Jean Wicht, Zhirui Xu, Hang Yin, Lei Zhang, Yi Zhang, Yu Zheng
Amer Physical Soc, 2016
Article

Résumé

The CP violation observables S and C in the decay channel B-0 -> D+D- are determined from a sample of proton-proton collisions at center-of-mass energies of 7 and 8 TeV, collected by the LHCb experiment and corresponding to an integrated luminosity of 3 fb(-1). The observable S describes CP violation in the interference between mixing and the decay amplitude, and C parametrizes direct CP violation in the decay. The following values are obtained from a flavor-tagged, decay-time-dependent analysis: S = -0.54(-0.16)(+0.17) (stat) +/- 0.05(syst) ,C=0.26(-0.17)(+0.18) (stat) +/- 0.02(syst). These values provide evidence for CP violation at a significance level of 4.0 standard deviations. The phase shift due to higher-order standard model corrections is constrained to a small value of Delta phi = -0.16(-0.21)(+0.19) rad.

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https://infoscience.epfl.ch/record/224904?ln=fr

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