Updated measurement of the strong phase in D0 → K+π- decay using quantum correlations in e+e- → D0(D)over-bar0 at CLEO

We analyze a sample of 3 X 10(6) quantum-correlated D-0(D) over bar (0) 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 D-0 -> K+pi(-) and Cabibbo-favored (D) over bar (0) -> K+pi(-) decay amplitudes. With no inputs from other experiments, we find cos delta = 0.81(-0.18-0.005)(+0.22+0.007), sin delta = -0.01 +/- 0.41 +/- 0.04, and vertical bar delta vertical bar = (10(-53-0)(+28+13))degrees. By including external measurements of mixing parameters, we find alternative values of cos delta = 1.15(-0.17-0.08)(+0.19+0.00), sin delta = 0.56(-0.31-0.20)(+0.32+0.21), and delta = (18(-17)(+11))degrees. Our results can be used to improve the world average uncertainty on the mixing parameter y by approximately 10%. DOI: 10.1103/PhysRevD.86.112001