Measurement of the angle \phi_3 with Dalitz analysis of three-body D^0 decay from B\to D^0 K process

TL;DR

This paper introduces a Dalitz analysis method to measure the CKM angle _3 using interference effects in D^0 decays from BD^0K processes, providing a new approach to CP violation studies.

Contribution

The paper presents a novel Dalitz analysis technique for _3 measurement, utilizing interference in D^0 decays from BD^0K, with statistical and systematic error evaluation.

Findings

Indication of CP asymmetry with 2.4 sigma significance.

90% confidence interval for _3: 61b0 to 142b0.

Analysis based on 140 fb^{-1} data sample.

Abstract

A new method to measure the angle $\phi_3$ of the CKM unitarity triangle using a Dalitz analysis of the three-body decay of the $D^0$ meson from the $B\to D^0 K$ process has been introduced recently. The method employs the interference between $D^0$ and $\bar{D^0}$ to extract both the weak and strong phases. We present a study of statistical and systematic errors of this method using Monte Carlo simulation. A fit of the $D^0$ Dalitz distribution has been performed based on a 140 fb$^{-1}$ sample collected by the Belle detector. We observe the indication of a CP asymmetry with the significance of 2.4 standard deviations. The 90% confidence interval obtained for the $\phi_3$ value is $61^{\circ}<\phi_3<142^{\circ}$.