Determination of the Strong Phase inD0→K+π−Using Quantum-Correlated Measurements

Abstract

We exploit the quantum coherence between pair-produced D0 and D[over]0 in psi(3770) decays to study charm mixing, which is characterized by the parameters x and y, and to make a first determination of the relative strong phase delta between D0-->K+pi- and D[over]0-->K+pi-. Using 281 pb(-1) of e+e- collision data collected with the CLEO-c detector at Ecm=3.77 GeV, as well as branching fraction input and time-integrated measurements of RM identical with (x2 + y2)/2 and RWS identical with Gamma(D0-->K+pi-)/Gamma(D[over]0-->K+pi-) from other experiments, we find cosdelta=1.03(-0.17)(+0.31)+/-0.06, where the uncertainties are statistical and systematic, respectively. By further including other mixing parameter measurements, we obtain an alternate measurement of cosdelta=1.10+/-0.35+/-0.07, as well as x sindelta=(4.4(-1.8)(+2.7)+/-2.9)x10(-3) and delta=(22(-12-11)(+11+9)) degrees .

Measurement ofD0−D¯0Mixing Parameters UsingD0→KSanchez1, Lees2, Poireau3 et al. 2010Phys. Rev. Lett.861220View full textAdd to dashboardCite

“…equivalent to 1.9 standard deviations and are in agreement with the range of SM predictions [1][2][3][4][5]. Our measurements favor lower values for x than for y, and lower x and y values (but still consistent) than those obtained when combining results from other D 0 decays [6][7][8][9][10][11]23]. Adding our results to the combination of all previous analyses significantly improves our current knowledge of the mixing parameters x and y, whose average values change from ð9:8 AE 2:5Þ Â 10 À3 and ð8:3 AE 1:6Þ Â 10 À3 to ð5:9 AE 2:0Þ Â 10 À3 and ð8:0 AE 1:3Þ Â 10 À3 , respectively [24].…”

Contributions to the width difference in the neutral D system from hadronic decays

“…The asymmetry for D 0 → K ∓ π ± decays has been measured to be A CP K ∓ π ± = (12.7 ± 1.3 ± 0.7) % [43] (see also Refs. [44][45][46]). Similar quantities for other quasi-flavour-specific decay modes can also be obtained from published results.…”

Charm Meson Mixing: An Experimental Review

“…37 Table 1. Correlated and uncorrelated decay rates for ST and DT events used in analysis of coherent D 0 D 0 decays by CLEO-c. 31,35 Rates are normalized to the branching fraction(s) of reconstructed mode(s) (note that a normalization is used where A 2 j is the D 0 branching fraction to mode j when no mixing is present). S + (S − ) denotes a decay to a CP = +1(−1) eigenstate; e − denotes a semileptonic decay containing e − .…”