Chien-Wen Hwang

Covariant Light-Front Approach for s-wave and p-wave Mesons: Its Application to Decay Constants and Form Factors

We study the decay constants and form factors of the ground-state s-wave and low-lying p-wave mesons within a covariant light-front approach. Numerical results of the form factors for transitions between a heavy pseudoscalar meson and an s-wave or p-wave meson and their momentum dependence are presented in detail. In particular, form factors for heavy-to-light and B to D** transitions, where D** denotes generically a p-wave charmed meson, are compared with other model calculations. The experimental measurements of the decays B^- to D** pi^- and B to D D**_s are employed to test the decay constants of D**_s and the B to D** transition form factors. The heavy quark limit behavior of the decay constants and form factors is examined and it is found that the requirement of heavy quark symmetry is satisfied. The universal Isgur-Wise (IW) functions, one for s-wave to s-wave and two for s-wave to p-wave transitions, are obtained. The values of IW functions at zero recoil and their slope parameters can be used to test the Bjorken and Uraltsev sum rules.

Two-photon and two-gluon decays of p-wave heavy quarkonium using a covariant light-front approach

In this paper, a study of two-photon and two-gluon decays in the context of p-wave heavy quarkonia is presented. Within the covariant light-front framework, the annihilation rates of scalar and tensor quarkonium states are derived. In the absence of free parameters in this case, the results for the charmonium decay widths are consistent with the experimental data. However, in comparison to other theoretical calculations, there are large discrepancies in our results regarding bottomonia.

Analyses of decay constants and light-cone distribution amplitudes for s-wave heavy meson

In this paper, a study of light-cone distribution amplitudes (LCDAs) for

SU(3)symmetry breaking in decay constants and electromagnetic properties of pseudoscalar heavy mesons

s

Isospin mass splittings of heavy baryons in heavy quark symmetry

-wave heavy meson are presented in both general and heavy quark frameworks. Within the light-front approach, the leading twist light-cone distribution amplitudes,

Study of light-cone distribution amplitudes for p-wave heavy mesons

{\ensuremath{\phi}}_{M}(u)

Light front approach for heavy pentaquark transitions

, and their relevant decay constants of heavy pseudoscalar and vector mesons,

Γ(phi → η'γ)/Γ(phi → ηγ) and the pseudoscalar mixing angle

{f}_{M}

Gamma(phi --> eta'gamma)/Gamma(phi --> etagamma) and the pseudoscalar mixing angle

, have simple relations. These relations can be further simplified when the heavy quark limit is taken into consideration. After fixing the parameters that appear in both Gaussian and power-law wave functions, the corresponding decay constants are calculated and compared with those of other theoretical approaches. The curves and the first six

?(phi ? ?'?)/?(phi ? ??) and the pseudoscalar mixing angle

\ensuremath{\xi}