Expected Accuracy in a Measurement of the CKM Angle $\alpha$ Using a Dalitz Plot Analysis of $\boldmath B^0 \to \rho \pi$ Decays in the BTeV Project

TL;DR

This paper demonstrates that the BTeV experiment can measure the CKM angle alpha with better than 5 degrees accuracy within one year using a Dalitz plot analysis of B0 to rho pi decays, providing a theoretically clean method.

Contribution

It introduces a Monte Carlo simulation-based approach combined with a time-dependent Dalitz plot analysis to accurately determine alpha in B0 to rho pi decays, enhancing measurement precision.

Findings

Achieves better than 5° accuracy on alpha within one year.

Estimates BTeV's reconstruction efficiency and signal-to-background ratio.

Validates the Dalitz plot analysis method for alpha measurement.

Abstract

A precise measurement of the angle $\alpha$ in the CKM triangle is very important for a complete test of Standard Model. A theoretically clean method to extract $\alpha$ is provided by B$^0 \to \rho \pi$ decays. Monte Carlo simulations to obtain the BTeV reconstruction efficiency and to estimate the signal to background ratio for these decays were performed. Finally the time-dependent Dalitz plot analysis, using the isospin amplitude formalism for tree and penguin contributions, was carried out. It was shown that in one year of data taking BTeV could achieve an accuracy on $\alpha$ better than 5$^{\circ}$.