Harmonic sums and Mellin transforms up to two loop order

Sep, 1998
44 pages
Published in:
  • Phys.Rev.D 60 (1999) 014018
e-Print:
Report number:
  • DESY-98-141

Citations per year

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Abstract:
A systematic study is performed on the finite harmonic sums up to level four. These sums form the general basis for the Mellin transforms of all individual functions fi(x)f_i(x) of the momentum fraction xx emerging in the quantities of massless QED and QCD up to two--loop order, as the unpolarized and polarized splitting functions, coefficient functions, and hard scattering cross sections for space and time-like momentum transfer. The finite harmonic sums are calculated explicitly in the linear representation. Algebraic relations connecting these sums are derived to obtain representations based on a reduced set of basic functions. The Mellin transforms of all the corresponding Nielsen functions are calculated.
Note:
  • 44 pages Latex, contract number added
  • expansion: harmonic
  • Mellin transformation
  • analytic properties
  • bibliography