Measurement of cos2beta in B0->D(*)h0 Decays with a Time-Dependent Dalitz Plot Analysis of D->KSpi+pi-

TL;DR

This paper measures the CP-violating parameter cos2beta in B0 decays using a time-dependent Dalitz plot analysis of D->KSpi+pi- with data from the BABAR detector, providing insights into CP violation.

Contribution

It presents the first measurement of cos2beta in B0 decays via a time-dependent Dalitz plot analysis of D->KSpi+pi-, including detailed uncertainty analysis.

Findings

Measured cos2beta = 0.42+-0.49+-0.09+-0.13

Determined sin2beta = 0.29+-0.34+-0.03+-0.05

Found that cos2beta>0 is preferred at 86% confidence level

Abstract

We study the time-dependent Dalitz plot of D->KSpi+pi- in B0->D(*)h0 decays, where h0 is a pi0, eta, eta', or omega meson and D*->Dpi0 using a data sample of 383 X 10^6 Upsilon(4S)->BBbar decays collected with the BABAR detector. We determine cos2beta = 0.42+-0.49+-0.09+-0.13, sin2beta = 0.29+-0.34+-0.03+-0.05, and |lambda| = 1.01+-0.08+-0.02, where the first error is statistical, the second is the experimental systematic uncertainty, and the third, where given, is the Dalitz model uncertainty. Assuming the world average value for sin2beta and |lambda|=1, cos2beta>0 is preferred over cos2beta<0 at 86% confidence level.