Measurement ofsin2βwith hadronic and previously unused muonicJ/ψdecays

B. Aubert, R. Barate, D. Boutigny, J.-M. Gaillard, A. Hicheur, Y. Karyotakis, J. P. Lees, P. Robbe, V. Tisserand, A. Zghiche, A. Palano, A. Pompili (+582 others)
2004 Physical Review D  
We report a measurement of the CP-violation parameter sin2beta with B^0 -> J/psi K^0_S decays in which the J/psi decays to hadrons or to muons that do not satisfy our standard identification criteria. With a sample of 88 million BBbar events collected by the BaBar detector at the PEP-II asymmetric-energy B factory at SLAC, we reconstruct 100 +/- 17 such events, with J/psi -> pi^+ pi^- pi^0 being the most prevalent, and measure sin2beta = 1.56 +/- 0.42 (stat.) +/- 0.21 (syst.).
doi:10.1103/physrevd.69.052001 fatcat:sdo4zkvxffehnfjf426esahfju