Resonance chiral Lagrangian currents and experimental data forτ−→π−π−π+ντ

Abstract

In this paper we document the modifications introduced to the previous version of the resonance chiral Lagrangian current [Phys. Rev. D 86, 113008 (2012)] of the AE ! AE AE Ç decay which enable the one-dimensional distributions measured by the BABAR Collaboration to be well modeled. The main change required to model the data is the addition of the resonance. Systematic errors, theoretical and experimental ones, limitations due to fits of one-dimensional distributions only, and resulting difficulties and statistical/systematic errors for fitted parameters are addressed. The current and fitting environment is ready for comparisons with the fully exclusive experimental data. The present result for AE ! AE AE Ç is encouraging for work on other decay modes and resonance chiral Lagrangian based currents.

Confronting theoretical predictions with experimental data; fitting strategy for multi-dimensional distributions

“…A set of semi-analytic distributions 10 had been prepared that correspond to the data distributions available to us. This required a substantial effort on the experimental side as well.…”

“…The estimated effect of this interaction on the results was relatively low; but for completeness, it had to be tested [10].…”

“…Because our model was unable to describe that region, we added the low-mass scalar σ resonance [12], which has been used in previous experiments to describe the low mass region, to our model. While the σ resonance is not well-defined by the theory, may not be a true resonance, and is not part of the RχL scheme, it has been added in a way that does not conflict with the RχL scheme (see [10], eq. (3)- (7)).…”

“…Since the focus of this paper is on the technical aspects of this project, we refer the reader to [10] for physics-related results. Instead, we will focus on performance results and validation process of the fitting framework in this section.…”

“…For the other aspects and physics details, we address the reader to references [16,10] as well as the references herein, for presentation of this rich and complicated activity.…”