Quantum-correlated measurements of $D\to K^{0}_{\rm S}\pi^{+}\pi^{-}\pi^{0}$ decays and consequences for the determination of the CKM angle $\gamma$

TL;DR

This study measures quantum correlations in specific D meson decays to improve the precision of CKM angle gamma determination, providing key phase and CP content data for future B decay analyses.

Contribution

It presents the first measurement of the CP-even fraction and strong-phase differences in D to K_S^0 pi+ pi- pi0 decays using quantum-correlated data, aiding gamma angle extraction.

Findings

CP-even fraction F_+ = 0.238 ± 0.012 ± 0.012

Strong-phase differences measured across phase space

Potential for improved gamma measurement sensitivity

Abstract

We perform quantum-correlated measurements of the decay $D \to K^{0}_{\rm S}\pi^{+}\pi^{-}\pi^{0}$ using a data sample corresponding to an integrated luminosity of 0.82 fb$^{-1}$ collected at the $\psi(3770)$ resonance by the CLEO-c detector. The value of the $CP$-even fraction $F_{+}$ is determined to be 0.238 $\pm$ 0.012 $\pm$ 0.012. The strong-phase differences are also measured in different regions of $K^{0}_{\rm S}\pi^{+}\pi^{-}\pi^{0}$ phase space by binning around the intermediate resonances present. The potential sensitivity of the results for determining the CKM angle $\gamma$ from $B^{\pm} \to D(K^{0}_{\rm S}\pi^{+}\pi^{-}\pi^{0})K^{\pm}$ decays is also discussed.