DOI 10.1007/s100529900063
QCD, conformal invariance and the two Pomerons
S. Munier - R. Peschanski
CEA, Service de Physique Theorique, CE-Saclay, F-91191 Gif-sur-Yvette Cedex, France
Received: 8 February 1999 / Revised version: 8 March 1999 / Published online: 18 June 1999
Abstract
Using the solution of the BFKL equation including the leading
and
subleading conformal spin components, we show how the conformal
invariance underlying the leading 
expansion of
perturbative QCD leads to elastic amplitudes described by two
effective Pomeron singularities. One Pomeron is the well-known
"hard'' BFKL leading singularity, while the new one appears
from
a shift of the higher conformal spin BFKL singularities from
subleading to leading position. This new effective singularity
is compatible with the "soft'' Pomeron and thus, together with
the
"hard'' Pomeron, meets at large Q2 the "double Pomeron''
solution which has recently been conjectured by Donnachie and
Landshoff.
Copyright Springer-Verlag
