B -meson wave function with contributions from three-particle Fock states

The B-meson light-cone wave functions, Ψ_±(ω,z²), are investigated up to the next-to-leading order in Fock state expansion in the heavy-quark limit. In order to know the transverse momentum dependence of the B-meson wave functions with 3-particle Fock states' contributions, we make use of the relations between 2- and 3- particle wave functions derived from the QCD equations of motion and the heavy-quark symmetry, especially two constraints derived from the gauge field equation of motion are employed. Our results show that the use of gluon equation of motion can give a constraint on the transverse momentum dependence χ(ω,k_⊥) of the B-meson wave functions, whose distribution tends to be a hyperbolalike curve under the condition 0<c₁<1, which is quite different from the Wandzura-Wilczek-(WW)-type wave functions, whose transverse momentum dependence χWW(ω,k_⊥) is merely a delta function. Based on the derived results, we propose a simple model for the B-meson wave functions with 3-particle Fock states' contributions.