Model-independent determination of the relative strong-phase difference between D0 and (D)over-bar0 → KS,L0π+π- and its impact on the measurement of the CKM angle γ/φ3

Crucial inputs for a variety of CP-violation studies can be determined through the analysis of pairs of quantum-entangled neutral D mesons, which are produced in the decay of the psi(3770) resonance. The relative strong-phase parameters between D-0 and (D) over bar (0) in the decays D-0 -> K-S,L(0)pi(+)pi(-) are studied using 2.93 fb(-1) of e(+)e(-) annihilation data delivered by the BEPCII collider and collected by the BESIII detector at a center-of-mass energy of 3.773 GeV. Results are presented in regions of the phase space of the decay. These are the most precise measurements to date of the strong-phase parameters in D-0 -> K-S,L(0)pi(+)pi(-) decays. Using these parameters, the associated uncertainty on the Cabibbo-Kobayashi-Maskawa angle gamma/phi(3) is expected to be between 0.7 degrees and 1.2 degrees for an analysis using the decay B-+/- -> DK +/-, D -> K-S(0)pi(+)pi(-), where D represents a superposition of D-0 and (D) over bar (0) states. This is a factor of 3 smaller than that achievable with previous measurements. Furthermore, these results provide valuable input for charm-mixing studies, other measurements of CP violation, and the measurement of strong-phase parameters for other D-decay modes.