Long-Distance Contributions to D^0-D^0bar Mixing Parameters

TL;DR

This paper evaluates long-distance effects on $D^0$-$ar D^0$ mixing parameters using recent decay data, finding results consistent with experimental measurements and discussing contributions from various two-body decay modes.

Contribution

It provides a comprehensive estimation of long-distance contributions to $D^0$-$ar D^0$ mixing parameters using updated decay data and diagrammatic approaches, including effects of different two-body modes.

Findings

$y$ is of order a few $ imes 10^{-3}$

$x$ is of order $10^{-3}$

Results agree with BaBar measurements

Abstract

Long-distance contributions to the $D^0$-$\bar D^0$ mixing parameters $x$ and $y$ are evaluated using latest data on hadronic $D^0$ decays. In particular, we take on two-body $D \to PP$ and $VP$ decays to evaluate the contributions of two-body intermediate states because they account for $\sim 50%$ of hadronic $D^0$ decays. Use of the diagrammatic approach has been made to estimate yet-observed decay modes. We find that $y$ is of order a few $\times 10^{-3}$ and $x$ of order $10^{-3}$ from hadronic $PP$ and $VP$ modes. These are in good agreement with the latest direct measurement of $D^0$-$\bar D^0$ mixing parameters using the $D^0 \to K_S \pi^+\pi^-$ and $K_S K^+ K^-$ decays by BaBar. We estimate the contribution to $y$ from the $VV$ modes using the factorization model and comment on the single-particle resonance effects and contributions from other two-body modes involving even-parity states.