Conformal symmetry of the Lange-Neubert evolution equation

Understand

The Lange-Neubert evolution equation describes the scale dependence of the wave function of a meson built of an infinitely heavy quark and light antiquark at light-like separations, which is the hydrogen atom problem of QCD.

• It has numerous applications to the studies of B-meson decays.
• We show that the kernel of this equation can be written in a remarkably compact form, as a logarithm of the generator of special conformal transformation in the light-ray direction.
• This representation allows one to study solutions of this equation in a very simple and mathematically consistent manner.