Heavy-to-light currents at NNLO in SCET and semi-inclusive anti-B ---> X(s) l+ l- decay

TL;DR

This paper calculates two-loop matching coefficients for heavy-to-light currents in SCET, impacting phenomenological predictions for B meson decays, including form factors and the semi-inclusive anti-B to X(s) l+ l- decay.

Contribution

It provides the complete two-loop matching calculation for heavy-to-light currents in SCET, a novel and essential step for precise phenomenological analyses.

Findings

Significant shift in the forward-backward asymmetry zero for anti-B ---> X(s) l+ l- decay.

Calculated q_0^2 = (3.34 +0.22 -0.25) GeV^2 for m_X^cut=2.0 GeV.

Enhanced understanding of decay distributions and form factor ratios.

Abstract

We perform the two-loop matching calculation for heavy-to-light currents from QCD onto soft-collinear effective theory for the complete set of Dirac structures. The newly obtained matching coefficients enter several phenomenological applications, of which we discuss heavy-to-light form factor ratios and exclusive radiative decays, as well as the semi-inclusive decay anti-B ---> X(s) l+ l-. For this decay, we observe a significant shift of the forward-backward asymmetry zero and find q_0^2 = (3.34 +0.22 -0.25) GeV^2 for an invariant mass cut m_X^cut=2.0 GeV.