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arXiv · hep-ph/9902375

Baryon Distribution Amplitudes in QCD

V. M. Braun·S. E. Derkachov·G. P. Korchemsky·A. N. Manashov
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Abstract

We develop a new theoretical framework for the description of leading twist light-cone baryon distribution amplitudes which is based on integrability of the helicity $λ=3/2$ evolution equation to leading logarithmic accuracy. A physical interpretation is that one can identify a new `hidden' quantum number which distinguishes components in the $λ=3/2$ distribution amplitudes with different scale dependence. The solution of the corresponding evolution equation is reduced to a simple three-term recurrence relation. The exact analytic solution is found for the component with the lowest anomalous dimension for all moments $N$, and the WKB-type expansion is constructed for other levels, which becomes asymptotically exact at large $N$. Evolution equations for the $λ=1/2$ distribution amplitudes (e.g. for the nucleon) are studied as well. We find that the two lowest anomalous dimensions for the $λ=1/2$ operators (one for each parity) are separated from the rest of the spectrum by a finite `mass gap'. These special states can be interpreted as scalar diquarks.

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V. M. Braun, S. E. Derkachov, G. P. Korchemsky, A. N. Manashov. 1999-02-17. Baryon Distribution Amplitudes in QCD. https://doi.org/10.1016/s0550-3213(99)00265-5

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