On the photoproduction of jets at HERA

Abstract

We discuss the inclusive jet production at HERA in the next-to-leading logarithm approximation. Theoretical uncertainties are considered in some details. We show the importance of the jet rapidity distribution to constrain the parton densities in the photon. A comparison is made with the recent H1 data.

Multilayer Ceramic Resonators Using a Flexural Vibration Mode and their Application to Filters

“…These results were obtained in [11]. Earlier work on NLO calculations of single inclusive jet cross sections for resolved and direct production can be found in [12][13][14][15][16]. As we would expect, the direct cross section has its maximum in the electron direction, i.e.…”

“…The H1 results are shown in figure 5 and compared to the NLO predictions of [11] calculated with the kinematical constraints of the H1 analysis and with the proton structure of GRV [21]. The data are also compared with two other NLO calculations: (i) instead of the NLO photon structure constructed by GRV, the photon structure function AFG constructed by Aurenche et al [22] is used in the JETSAM program [23] based on [11]; (ii) results of an independent calculation by Aurenche et al [16] with the photon structure function AFG and a somewhat different proton structure function ABFOW based on older work [24]. Small differences between the predictions (i) and (ii) can be explained by the choice of a different proton structure function and, in addition, by a choice of a different overall scale µ = E T /2 in (ii) instead of the scale µ = E T in (i).…”

“…The NLO calculations are compared with the JETSAM program [23] using GRV [19] (full curve) and AGF [22] (dot-dashed curve) photon structure functions and compared with Aurenche et al [16] (dashed curve). to (i) and (ii) demonstrate that the two independent calculations of Klasen et al [11] and Aurenche et al [16] agree very well. Small differences can be explained with the use of different input for the proton structure function and the scale.…”

Survey of present data on photon structure functions and resolved photon processes

“…Here the comparison was made with the NLO calculation [183] with the GRV HO, AGF HO and GS96 HO parton parametrization for the photon (the CTEQ4M parametrization for the proton). Also the comparison between the different NLO calculations ( [176,188,185,186,187]) is made using the particular (GRV-HO) parton parametrization. Comment: The underlying events "play no role in the present kinematic regime."…”

Optical spectroscopy of trapped neutral atoms

“…NLO QCD calculations of inclusive jet cross sections have been carried out by several groups [104,105,106,107,108]. These calculations involve at most three partons in the nal state, from which jets are dened by the same cone algorithm as used for data.…”