Higher order QCD corrections in exclusive charmless B decays

TL;DR

This paper advances the understanding of exclusive charmless B decays by computing NNLO QCD corrections, analyzing form factors, and exploring non-relativistic bound state dynamics, crucial for CP violation studies.

Contribution

It provides the first NNLO QCD corrections to hadronic B decays and introduces a conceptual framework for form factors involving non-relativistic states.

Findings

NNLO QCD corrections significantly affect strong phases and CP asymmetries.

Calculated the imaginary part of topological tree amplitudes.

Developed a method to compute form factors for non-relativistic bound states.

Abstract

We discuss exclusive charmless B decays within the Standard Model of particle physics. In particular, we consider hadronic two-body decays as B -> pi pi and perform a conceptual analysis of heavy-to-light form factors which encode the strong interaction effects in semi-leptonic decays as B -> pi l nu. Concerning the hadronic decays we compute NNLO QCD corrections which are particularly important with respect to strong interaction phases and hence direct CP asymmetries. We present results for the imaginary part of the topological tree amplitudes and a partial calculation of the real part of the amplitudes which is technically more involved. In our conceptual analysis of the QCD dynamics in heavy-to-light transitions we consider form factors between non-relativistic bound states. We perform a NLO analysis and compute the so-called soft-overlap contribution which is calculable in our set-up. As a byproduct of our analysis, we calculate leading-twist light-cone distribution amplitudes for non-relativistic bound states which can be applied for B_c or eta_c mesons.