Transverse Momentum Dependent Light-Cone Wave Function of B-Meson and Relation to the Momentum Integrated One

Abstract

A direct generalization of the transverse momentum integrated(TMI) light-cone wave function to define a transverse momentum dependent(TMD) light-cone wave function will cause light-cone singularities and they spoil TMD factorization. We motivate a definition in which the light-cone singularities are regularized with non-light like Wilson lines. The defined TMD light-cone wave function has some interesting relations to the corresponding TMI one. When the transverse momentum is very large, the TMD light-cone wave function is determined perturbatively in term of the TMI one. In the impact $b$-space with a small $b$, the TMD light-cone wave function can be factorized in terms of the TMI one. In this letter we study these relations. By-products of our study are the renormalization evolution of the TMI light-cone wave function and the Collins-Soper equation of the TMD light-cone wave function, the later will be useful for resumming Sudakov logarithms.