Light-front holographic distribution amplitudes of pseudoscalar mesons and their application to $B$-meson decays

TL;DR

This paper develops improved light-front holographic distribution amplitudes for pseudoscalar mesons, demonstrating their consistency with experimental data and their effectiveness in regulating divergences in B-meson decay calculations.

Contribution

It introduces dynamical spin effects into holographic wavefunctions and applies them to B-meson decays, providing a more accurate description of hadronic observables.

Findings

Consistent holographic parameters with Regge trajectory slopes

Improved wavefunctions match decay constants and form factors

Regulate end-point divergences in B decay amplitudes

Abstract

In this paper the dynamical spin effects of the light-front holographic wavefunctions for light pseudoscalar mesons are studied using two different assumptions. These improved wavefunctions are then confronted with a number of sensitive hadronic observables: the decay constants of $\pi$ and $K$ mesons, their $\xi$-moments, the pion-to-photon transition form factor, and the pure annihilation $\bar{B}_{s}\to \pi^+ \pi^-$ and $\bar{B}_{d}\to K^+K^-$ decays. Taking $f_{\pi}$, $f_{K}$ and their ratio $f_{K}/f_{\pi}$ as constraint conditions, the $\chi^2$ analyses for holographic parameters, including the mass scale parameter $\sqrt{\lambda}$ and effective quark masses, are all consistent with the mass scale which controls the slopes of the light-quark hadronic Regge trajectories. In addition, we also show how the improved light-front holographic distribution amplitudes regulate the end-point divergences which appear in the annihilation amplitudes of $B\to PP$ decays.