Anomalous dimension of the twist four gluon operator and pomeron cuts in deep inelastic scattering

Small-xF2structure function of a nucleus including multiple Pomeron exchanges

“…(15). This equation describes the evolution of N (x 01 , b 0 , Y ) in the leading ln(1/x) and does not assume collinear factorization or impose transverse momentum cutoffs, therefore posing no problems like the mixing of operators of different twists [32].…”

“…However there is some freedom in the definition of the gluon distribution. If one makes us of the general definition of the gluon distribution as a matrix element of leading twist operator, then an attempt to take into account higher twist operators would lead only to renormalization of their matrix elements (see [32] and references therein). The evolution equation for xG would be linear, with all the non-linear saturation effects included in the initial conditions.…”

Reggeon field theory for large Pomeron loops

“…A possibility that RFT should involve a 2 → 2 Pomeron vertex has been previously discussed in the literature [60,[70][71][72][73][74][75]. Recently, Braun [76,77] argued that such a vertex appears in the BKP formalism and can be relevant for collisions of two deuterons.…”

“…(3.43). An interesting property of this Hamiltonian is that it generates the additional contribution to the two Pomeron Green's function [70][71][72][73] through graphs illustrated on figure 3. This has the effect that in the linearized approximation the two Pomeron Green's function increases faster than the product of two the single Pomeron exchanges: ω P P = 2 ω P + λ/N 2 c δ where δ is a small number (see ref.…”

“…This has the effect that in the linearized approximation the two Pomeron Green's function increases faster than the product of two the single Pomeron exchanges: ω P P = 2 ω P + λ/N 2 c δ where δ is a small number (see ref. [70][71][72][73] for details). This contribution starts to be essential with rapidities η ∝ N 2 c /λ > η max .…”