Jet production in deep inelastic electron-photon scattering at e+e− colliders in next-to-leading order QCD

Abstract

A complete next-to-leading order QCD calculation of deep inelastic electron-photon scattering including direct and resolved real photon components is presented. Soft and collinear singularities are extracted using the phase space slicing method. Application of the results for the prediction of single-and dijet cross sections at the LEP e + e − collider are presented, using the Snowmass jet definition. The dependence of the cross sections on the transverse momentum and on the rapidities of the jets are discussed.

Inclusive hard processes in γγ and γp interactions

“…The cross section for jet production using virtual photons at LO QCD is similar to that for real photons except that the photon parton densities are replaced by those of the virtual photon. NLO QCD calculations for jet production using virtual photons in γ * p [ 56] and γ * γ [ 57] interactions have been recently completed.…”

Probing the parton densities of virtual photons with the reaction at LEP

“…The definition of the partonic cross sections dσ U,L γ * b are given in [11]. For the SR case, the NLO calculations can be taken from [21], whereas the NLO calculations for the D case have been presented in [11]; both calculations employ the phase-space-slicing method to extract the singular phase-space regions of the real corrections. The singular integrals of both the real and the virtual corrections are handled in dimensional regularization.…”

“…This reaction can be obtained at e + e − colliders by single-tag experiments, and preliminary results have been reported from the OPAL collaboration at LEP [10] for 6 ≤ Q 2 ≤ 30 GeV 2 . For the large Q 2 region we have recently evaluated the NLO QCD corrections to this process and found them to be small and to improve the scale dependence [11]. Moving towards the region of small virtualities, especially for Q 2 ≪ E 2 T , one expects logarithms from the initial state γ * → qq splitting of the form ln(Q 2 /s), where √ s is the partonic center-of-mass energy, to become large and spoil the convergence of the perturbative expansion.…”

“…With the subtraction performed, one has to include a resolved virtual photon contribution into the jet cross sections. In the deepinelastic case as described in [11], the virtual photon couples only directly and the real…”

Characterization of jets in relativistic heavy ion collisions

“…The properties of jets produced in e + −e − and hadron-hadron collisions have been well investigated [8,9] and the systematics of number of particles in a jet and the opening angle of the jet have been done. There is also a good theoretical understanding of these in terms of perturbative QCD and jet fragmentation functions [9,10].…”