First measurement of phi_3 with a binned model-independent Dalitz plot analysis of B->DK, D->Ks pi+pi- decay

TL;DR

This paper reports the first measurement of the CKM unitarity triangle angle phi_3 using a model-independent Dalitz plot analysis of B->DK, D->Ks pi+pi- decays, leveraging data from the Belle experiment and CLEO measurements.

Contribution

It introduces a novel, model-independent Dalitz plot analysis method for measuring phi_3, utilizing strong phase parameters from CLEO and Belle data.

Findings

Measured phi_3 = (77.3^{+15.1}_{-14.9} +- 4.2 +- 4.3) degrees.

Determined the suppressed amplitude ratio rB = 0.145 +- 0.030 +- 0.011 +- 0.011.

First application of this method to experimental data.

Abstract

We present the first measurement of the angle phi_3 of the unitarity triangle using a binned model-independent Dalitz plot analysis technique of B->DK, D->Ks pi+pi- decay chain. The method is based on the measurement of parameters related to the strong phase of D->Ks pi+ pi- amplitude performed by the CLEO collaboration. The analysis uses full data set of 772x10^6 BBbar pairs collected by the Belle experiment at Upsilon(4S) resonance. We obtain phi3 = (77.3^{+15.1}_{-14.9} +- 4.2 +- 4.3) degree and the suppressed amplitude ratio rB = 0.145 +- 0.030 +- 0.011 +- 0.011. Here the first error is statistical, the second is experimental systematic uncertainty, and the third is the error due to precision of strong phase parameters obtained by CLEO. This result is preliminary.