Measurement of the angle ϕ_3 with Dalitz analysis of three-body D^0 decay from B\to D^0 K process
Abstract
A new method to measure the angle
ϕ
3
of the CKM unitarity triangle using a Dalitz analysis of the three-body decay of the
D
0
meson from the
B→
D
0
K
process has been introduced recently. The method employs the interference between
D
0
and
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
ϕ
3
value is
61
∘
<
ϕ
3
<
142
∘
.