Heavy pseudoscalar-meson decay constants with strangeness from the extended nonlocal chiral-quark model

TL;DR

This paper calculates decay constants for heavy pseudoscalar mesons using an extended nonlocal chiral-quark model, incorporating strange-quark effects, and finds results consistent with experimental data and theoretical estimates.

Contribution

It introduces an extended nonlocal chiral-quark model that includes strange-quark corrections to accurately compute heavy meson decay constants.

Findings

Decay constants agree with experimental data.

CKM matrix elements are consistent with known values.

The model effectively incorporates strange-quark effects.

Abstract

We study the weak-decay constants for the heavy pseudoscalar mesons, D, Ds, B, and Bs. For this purpose, we employ the extended nonlocal chiral-quark model (ExNLChQM), motivated by the heavy-quark effective field theory as well as the instanton-vacuum configuration. In addition to the heavy-quark symmetry and the nonlocal interactions between quarks and pseudoscalar mesons in ExNLChQM, a correction for the strange-quark content inside Ds and Bs is also taken into account and found to be crucial to reproduce the empirical values. From those numerical results, we obtain f_{D,Ds,B,Bs}=(207.53, 262.56, 208.13, 262.39) MeV, which are in good agreement with experimental data and other theoretical estimations. Using those numerical results, we compute the CKM matrix elements and the Cabibbo angle, using various mesonic and leptonic heavy-meson decay channels, resulting in (|V_{cd}|,|V_{cs}|,|V_{ub}|,|V_{td}|/|V_{ts}|)=(0.224,0.968,<5.395*10^{-3},0.215) and theta_C=12.36^o which are well compatible with available data.