Non-dipolar gauge links for transverse-momentum-dependent pion wave functions

Abstract

I discuss the factorization-compatible definitions of transverse-momentum-dependent (TMD) pion wave functions which are fundamental theory inputs entering QCD factorization formulae for many hard exclusive processes. I will first demonstrate that the soft subtraction factor introduced to remove both rapidity and pinch singularities can be greatly reduced by making the maximal use of the freedom to construct the Wilson-line paths when defining the TMD wave functions. I will then turn to show that the newly proposed TMD definition with non-dipolar Wilson lines is equivalent to the one with dipolar gauge links and with a complicated soft function, to all orders of the perturbative expansion in the strong coupling, as far as the infrared behavior is concerned.

7 pages, 3 figures

References in corpus (7)

• Matches and mismatches in the descriptions of semi-inclusive processes at low and high transverse momentum
• Light Cone Sum Rules for the pi0-gamma*-gamma Form Factor Revisited
• Next-to-leading-order corrections to exclusive processes in $k_T$ factorization
• The NLO twist-3 contributions to $B\to \pi$ form factors in $k_T$ factorization
• Joint resummation for pion wave function and pion transition form factor
• Gauge Invariance and k_T-Factorization of Exclusive Processes
• Rapidity resummation for $B$-meson wave functions

Cited by in corpus (6)

• Precision calculations of $B\to V$ form factors in QCD
• QCD calculations of $B\to \pi ,K$ form factors with higher-twist corrections
• Precision calculations of $B_{d,s}\to \pi ,K$ decay form factors in soft-collinear effective theory
• $B\to D\ell {\nu }_{\ell }$ form factors beyond leading power and extraction of $|V_{cb}|$ and $R(D)$
• Pion and Kaon form factors in the perturbative QCD approach
• Rho-pion transition form factors in the $k_T$ factorization formulism revisited