Measurement of phi_3 with Dalitz plot analysis of B+ -> D(*)K(*)+ decay

TL;DR

This paper measures the unitarity triangle angle phi_3 using Dalitz plot analysis of B+ decays to D(*)K(*)+ with interference effects, analyzing data from the Belle experiment to determine phi_3 with quantified uncertainties.

Contribution

It introduces a Dalitz plot analysis method for phi_3 measurement in B+ decays, combining multiple decay modes and interference effects for improved precision.

Findings

Measured phi_3 as 53 degrees with uncertainties.

Determined the two standard deviation interval for phi_3 as 8 to 111 degrees.

Applied the method to 357 fb-1 data from Belle.

Abstract

We present a measurement of the unitarity triangle angle phi_3 using a Dalitz plot analysis of the K0_S pi+ pi- decay of the neutral D meson from the B+- -> D(*)K(*)+- process. The method employs the interference between D0 and D0bar to extract the angle phi_3, strong phase Delta and the ratio r of suppressed and allowed amplitudes. We apply this method to a 357 fb-1 data sample collected by the Belle experiment. The analysis uses three modes: B+ -> DK+, B+ -> D*K+ with D* -> Dpi0, and B+ -> DK*+ with K*+ -> K0_S pi+, as well as the corresponding charge-conjugate modes. From a combined maximum likelihood fit to the three modes, we obtain phi_3=53+15-18(stat)+-3(syst)+-9(model) degrees. The corresponding two standard deviation interval is 8<phi_3<111 degrees.