Baryon distribution amplitudes in QCD

Feb, 1999
75 pages
Published in:
  • Nucl.Phys.B 553 (1999) 355-426
e-Print:
Report number:
  • LPT-ORSAY-98-83,
  • NORDITA-99-11-HE,
  • SPBU-IP-99-04

Citations per year

199720042011201820240102030
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\lambda=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\lambda=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 NN, and the WKB-type expansion is constructed for other levels, which becomes asymptotically exact at large NN. Evolution equations for the λ=1/2\lambda=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\lambda=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.
Note:
  • 75 pages, LaTeX style, 18 figures embedded with epsf.sty Report-no: LPT-Orsay-98-83, NORDITA-99-11-HE, SPbU-IP-99-04
  • baryon: wave function
  • helicity
  • quantum chromodynamics
  • effect: higher-twist
  • light cone
  • renormalization
  • invariance: conformal
  • group theory
  • integrability
  • symmetry: discrete