Speaker
Description
Baryon light-cone distribution amplitudes (LCDAs) encode the longitudinal momentum distributions of valence quarks and provide important nonperturbative inputs for hard exclusive processes involving baryons. In this talk, I will present the first lattice determination of the three leading-twist $\Lambda$-baryon LCDAs, $V$, $A$, and $T$, as full two-dimensional functions of the valence-quark momentum fractions.
This work establishes a systematic large-momentum effective theory (LaMET) framework for determining leading-twist baryon LCDAs from lattice QCD, covering the complete procedure from equal-time three-quark correlators to the momentum-fraction dependence of physical light-cone amplitudes. Key ingredients include a two-dimensional hybrid renormalization prescription in coordinate space, an HQET-motivated large-$\lambda$ extrapolation strategy for controlling the long-distance behavior of Euclidean correlators, one-loop perturbative matching to the light-cone amplitudes in the $\overline{\rm MS}$ scheme, and controlled extrapolations to the continuum, physical-pion-mass, and infinite-momentum limits.
As a phenomenological illustration, replacing the asymptotic LCDA with the lattice-determined distributions leads to an $\mathcal{O}(10\%)$ shift in the $\Lambda$ electromagnetic form factor at perturbative scales. These results provide the first complete multidimensional, $x$-dependent baryon LCDAs from first principles and establish a framework for future lattice studies of baryon light-cone structure.
