1210.0939 (CLEO Collaboration et al.)

Updated Measurement of the Strong Phase in D0 --> K+pi- Decay Using
Quantum Correlations in e+e- --> D0 D0bar at CLEO    [PDF]

CLEO Collaboration, D. M. Asner, G. Tatishvili, J. Y. Ge, D. H. Miller, I. P. J. Shipsey, B. Xin, G. S. Adams, J. Napolitano, K. M. Ecklund, Q. He, J. Insler, H. Muramatsu, L. J. Pearson, E. H. Thorndike, M. Artuso, S. Blusk, N. Horwitz, R. Mountain, T. Skwarnicki, S. Stone, J. C. Wang, L. M. Zhang, P. U. E. Onyisi, G. Bonvicini, D. Cinabro, A. Lincoln, M. J. Smith, P. Zhou, P. Naik, J. Rademacker, K. W. Edwards, E. J. White, R. A. Briere, H. Vogel, P. U. E. Onyisi, J. L. Rosner, J. P. Alexander, D. G. Cassel, S. Das, R. Ehrlich, L. Gibbons, S. W. Gray, D. L. Hartill, D. L. Kreinick, V. E. Kuznetsov, J. R. Patterson, D. Peterson, D. Riley, A. Ryd, A. J. Sadoff, X. Shi, S. Stroiney, W. M. Sun, J. Yelton, P. Rubin, N. Lowrey, S. Mehrabyan, M. Selen, J. Wiss, J. Libby, M. Kornicer, R. E. Mitchell, D. Besson, T. K. Pedlar, D. Cronin-Hennessy, J. Hietala, S. Dobbs, Z. Metreveli, K. K. Seth, A. Tomaradze, T. Xiao, A. Powell, C. Thomas, G. Wilkinson

We analyze a sample of 3 million quantum-correlated D0 D0bar pairs from 818 pb^-1 of e+e- collision data collected with the CLEO-c detector at E_cm = 3.77 GeV, to give an updated measurement of \cos\delta and a first determination of \sin\delta, where \delta is the relative strong phase between doubly Cabibbo-suppressed D0 --> K+pi- and Cabibbo-favored D0bar --> K+pi- decay amplitudes. With no inputs from other experiments, we find \cos\delta = 0.81 +0.22+0.07 -0.18-0.05, \sin\delta = -0.01 +- 0.41 +- 0.04, and |\delta| = 10 +28+13 -53-0 degrees. By including external measurements of mixing parameters, we find alternative values of \cos\delta = 1.15 +0.19+0.00 -0.17-0.08, \sin\delta = 0.56 +0.32+0.21 -0.31-0.20, and \delta = (18 +11-17) degrees. Our results can be used to improve the world average uncertainty on the mixing parameter y by approximately 10%.

View original: http://arxiv.org/abs/1210.0939