Systematic Analysis of B --> K pi l^+ l^- Decay through Angular Decomposition

TL;DR

This paper presents a systematic angular analysis of B --> K pi l^+ l^- decay to identify potential new physics effects through detailed CP asymmetry measurements, leveraging interference effects from resonances.

Contribution

It introduces a comprehensive angular decomposition method to extract multiple CP asymmetries, including time-dependent and direct CP asymmetries, in four-body B decay processes.

Findings

Enhanced CP asymmetries possible due to resonance interference.

New angular observables can reveal weak CP phases from new physics.

Method provides detailed insight into new physics contributions.

Abstract

We investigate systematically how to extract new physics contributions in B --> K pi l^+ l^- decay by using the angular decomposition. The decomposition will enable us to define not only several CP averaged forward-backward (FB) asymmetries but also the direct CP asymmetry and the time-dependent mixing induced CP asymmetry for each FB asymmetry newly defined in the general 4 body angular space. The decay process involves several intermediate vector and scalar resonances as sources of strong phase difference through interference, therefore, one can expect largely enhanced CP asymmetries, if there exists any new physics with weak CP phases. The combined analysis of the FB and CP asymmetries will give us fruitful information about new physics contributions in detail.