Twist-2 pseudoscalar and vector meson distribution amplitudes in light-front quark model with exponential-type confining potential

Nisha Dhiman,Ho-Meoyng Choi,Harleen Dahiya,Chueng-Ryong Ji

doi:10.1103/physrevd.100.014026

Abstract

We study the twist-2 distribution amplitudes (DAs) and the decay constants of pseudoscalar light ($\pi$, $K$) and heavy ($D$, $D_s$, $B$, $B_s$) mesons as well as the longitudinally and transversely polarized vector light ($\rho$, $K^*$) and heavy ($D^*$, $D_s^*$, $B^*$, $B_s^*$) mesons in the light-front quark model with the Coulomb plus exponential-type confining potential $V_{\rm {exp}} = a + b e^{\alpha r}$ in addition to the hyperfine interaction. We first compute the mass spectra of ground state pseudoscalar and vector light and heavy mesons and fix the model parameters necessary for the analysis, applying the variational principle with the trial wave function up to the first three lowest order harmonic oscillator (HO) wave functions $\Phi(x, \textbf{k}_\bot) = \sum_{n=1}^{3} c_n \phi_{nS}$. We then obtain the numerical results for the corresponding decay constants of light and heavy mesons. We estimate the DAs, analyze their variation as a function of momentum fraction and compute the first six $\xi$-moments of the $B$ and $D$ mesons as well. We compare our results with the available experimental data as well as with the other theoretical model predictions.

Highlights

In the last few decades, the light as well as heavy quark mesonic systems have provided a great deal of important and attractive information on the precise determination of the fundamental parameters of the Standard Model (SM)
It is interesting to note in this work that our light-front quark model (LFQM) predictions are comparable to each other regardless the type of confining potential as far as the efficacy of model prediction is achieved by allowing sufficient number of harmonic oscillator (HO) basis functions for the trial wave function
We have studied the mass spectra, decay constants and the twist-2 distribution amplitudes (DAs) of pseudoscalar and vector light (π, K) and heavy (D, Ds, B, Bs) mesons within the LFQM with the exponential-type confining potential

Summary

INTRODUCTION

In the last few decades, the light as well as heavy quark mesonic systems have provided a great deal of important and attractive information on the precise determination of the fundamental parameters of the Standard Model (SM). The ground state mass spectra and the decay constants of pseudoscalar and vector heavy mesons have already been analyzed by fixing the model parameters obtained from the linear and harmonic oscillator (HO) confining potentials using the 1S state HO wave function in the light-front approach [72]. The mass spectra and decay constants of ground state pseudoscalar and vector light and heavy mesons have been computed in the LFQM by fixing the model parameters obtained from the linear confining potential using the two lowest order HO wave functions [73]. In the Appendix, we present the analytic formula of the mass eigenvalues of the ground state pseudoscalar and vector mesons by fixing the model parameters obtained from the exponential-type potential using the mixture of three lowest order HO states as our trial wave function for the variational principle

LIGHT-FRONT QUARK MODEL

FIXATION OF MODEL PARAMETERS AND MESON MASS SPECTRA

QUARK DISTRIBUTION AMPLITUDES AND DECAY CONSTANTS

Summary of formulas

Numerical results

SUMMARY AND CONCLUSIONS