Updated model-independent measurement of the strong-phase differences between $D^0$ and $\bar{D}^0 \to K^{0}_{S/L}π^+π^-$ decays

Abstract

The strong-phase differences between $D^0\to K_{S/L}^0π^+π^-$ and $\bar{D}^0\to K_{S/L}^0π^+π^-$ decays are one of the most important inputs in measuring the $C\!P$ violating angle $γ$ via $B^- \to D K^-$ decays. They also play a key role in studies of charm mixing and indirect $C\!P$ violation. In this paper, the strong-phase differences are determined in a model-independent way with quantum-correlated $D^0$-$\bar{D}^0$ decays from 7.93 fb$^{-1}$ of $e^+e^-$ annihilation data at $\sqrt{s}$=3.773 GeV by the BESIII experiment. These results are the most precise to date and are expected to significantly reduce associated uncertainties in determining the $C\!P$ violating angle $γ$ and related charm mixing parameters.

Figures (11)

• Figure 1: Binned regions marked as different colors indexed from 1 to 8 in the equal binning scheme (left), optimal binning scheme (middle) and modified-optimal binning scheme (right).
• Figure 2: Fits to the $M_{\rm BC}$ distributions of ST signal events. The black points with error bars represent data where peaking background has been subtracted. The red solid lines represent the fit to data. The signal and background components are shown as blue and green dashed lines.
• Figure 3: The 1D unbinned maximum likelihood fits for $K^{0}_{S}\pi^+\pi^-$ versus full reconstructed modes on $M_{\rm BC}$. The black points with error bars represent data. The dashed lines indicate the signal and background shapes. The red lines represent the sum of signal and background shapes. The fitting plots in logarithm scale are shown in Figure \ref{['fig:ksfitted2_log']}.
• Figure 4: The 1D unbinned maximum likelihood fits for $K^{0}_{S}\pi^+\pi^-$ versus partially reconstructed tags on $M^{2}_{\rm miss}/U_{\rm miss}$. The black points with error bars represent data. The dashed lines indicate the signal and background shapes. The red lines represent the sum of signal and background shapes. The fitting plots in logarithm scale are shown in Figure \ref{['fig:ksfitted_log']}.
• Figure 5: The 1D unbinned maximum likelihood fits for $K^{0}_{L}\pi^+\pi^-$ versus various tag modes on $M^{2}_{\rm miss}$. The black points with error bars represent data. The dashed lines indicate the signal and background shapes. The red lines represent the sum of signal and background shapes. The fitting plots in logarithm scale are shown in Figure \ref{['fig:klfitted_log']}.