The Scalar Meson f0(980) in Heavy-Meson Decays

TL;DR

This paper analyzes the scalar meson f0(980) in heavy-meson decays using a covariant quark model, extracting its structure and predicting decay form factors for D, Ds, B, and Bs mesons.

Contribution

It introduces a comprehensive phenomenological approach combining experimental data and relativistic models to study the f0(980) meson in heavy-meson decays, including its quark structure and decay form factors.

Findings

Determined the f0(980) wave function components and mixing angle.

Computed transition form factors for D, Ds, B, and Bs decays involving f0(980).

Predicted decay rates and form factors across the full kinematic range.

Abstract

A phenomenological analysis of the scalar meson f0(980) is performed that relies on the quasi-two body decays D and Ds -> f0(980)P, with P=pi, K. The two-body branching ratios are deduced from experimental data on D or Ds -> pi pi pi, K Kbar pi and from the f0(980) -> pi+ pi- and f0(980) -> K+ K- branching fractions. Within a covariant quark model, the scalar form factors F0(q2) for the transitions D and Ds -> f0(980) are computed. The weak D decay amplitudes, in which these form factors enter, are obtained in the naive factorization approach assuming a quark-antiquark state for the scalar and pseudoscalar mesons. They allow to extract information on the f0(980) wave function in terms of u-ubar, d-dbar and s-sbar pairs as well as on the mixing angle between the strange and non-strange components. The weak transition form factors are modeled by the one-loop triangular diagram using two different relativistic approaches: covariant light-front dynamics and dispersion relations. We use the information found on the f0(980) structure to evaluate the scalar and vector form factors in the transitions D and Ds -> f0(980), as well as to make predictions for B and Bs -> f0(980), for the entire kinematically allowed momentum range of q2.