Diffractive Parton Distributions

We present here diffractive parton distributions, which are to be used for calculating diffractive hard cross sections in deeply inelastic scattering (for instance the diffractive structure functions or diffractive jet production).

Reference

F. Hautmann and D. E. Soper, Phys. Rev. D 63, 011501 (2000).

Definitions

These distributions are calculated from a QCD model for diffractive hard scattering, as described in the reference above. They are integrated over the momentum transfer variable t from t = 0 to a value t_max of approximately 1 GeV.

The diffractive parton distributions have the form

f_i(beta,x_pom,mu) = (1/x_pom)*(x₀/x_pom)^{2 delta} F_i(beta,mu)

The parameters x₀ and delta are determined from data. The values found in the reference above are x₀ = 0.01 and delta = 0.15.

The values of F_i(beta,mu) are given in the table below.

The table was determined by applying the usual parton evolution equations to the starting values at mu = 1.5 GeV for up, down, and strange quarks, as given in the reference listed above. The evolution used generates non-zero heavy flavor quark distributions starting at the relevant flavor thresholds.

Parton distribution tables

HS00 parton distribution table.

Davison E. Soper and Parvez Anandam
Institute of Theoretical Science, University of Oregon, Eugene OR 97403 USA
soper@bovine.uoregon.edu