Showing papers by "Edmond L. Berger published in 1991"
TL;DR: This paper provides a consistent treatment of the isolated prompt-photon cross section in QCD perturbation theory and addresses both the short- and the long-distance issues in detail, showing that well-behaved predictions can be derived for a wide range of isolation parameters.
Abstract: Cross sections for prompt-photon production at collider energies are not strictly inclusive because an isolation requirement is imposed whereby the photon is detected only if accompanied by a restricted amount of hadronic energy. In this paper we provide a consistent treatment of the isolated prompt-photon cross section in QCD perturbation theory. The isolation requirement reduces sensitivity of the cross section to poorly known long-distance fragmentation contributions. However, the normal cancellation of infrared singularities is upset by the isolation cutoffs, rendering the shortdistance perturbative calculation highly nontrivial. In our solution we address both the short- and the long-distance issues in detail, showing that well-behaved predictions can be derived for a wide range of isolation parameters. Calculated cross sections are presented at several energies and scale dependence of the cross section is examined.
44 citations
TL;DR: It is found that ISAGET cross sections at large {ital p}{sub {ital T}} are greater than the results obtained in the analytical calculation, and the implications of these overestimates that relate to the phenomenology of heavy-flavor production are discussed.
Abstract: High-statistics samples of events have been generated with the ISAGET Monte Carlo simulation program in a study of bottom-quark production in proton-antiproton collisions at {radical}{ital s} =630 and 1800 GeV. These samples include lowest-order QCD production, flavor excitation, and gluon splitting contributions. Both Eichten-Hinchliffe-Lane-Quigg and Diemoz-Ferroni-Longo-Martinelli structure functions have been used. The integral transverse-momentum distribution {sigma}{sub {ital T}}({ital p}{sub {ital T},}{ital b}{gt}{ital p}{sub {ital T},min}) is presented for each data set. Results are compared to a full analytical next-to-leading-order calculation of Nason, Dawson, and Ellis. We find that ISAGET cross sections at large {ital p}{sub {ital T}} are greater than the results obtained in the analytical calculation. In addition, the ratio of the full cross section to the lowest-order result ({ital K} factor) can be as large as a factor of 2 greater than the analytical result, depending on {radical}{ital s} and {ital p}{sub {ital T}}. We discuss the implications of these overestimates that relate to the phenomenology of heavy-flavor production, notably searches for the top quark.
1 citations
TL;DR: In this article, a review of heavy quark production in {bar p}p, {pi}{sup -}p and pp interactions at fixed target and collider energies is presented.
Abstract: A review is presented of heavy quark production in {bar p}p, {pi}{sup -}p, and pp interactions at fixed target and collider energies. Calculations of total cross sections and of single quark inclusive differential cross sections d{sup 2}{sigma}/dk{sub T}dy are described including contributions through next-to-leading order in QCD perturbation theory. Comparisons with available data on charm and bottom quark production show good agreement for reasonable values of the charm and bottom quark masses and other parameters. Predictions and open issues in the interpretation of results are summarized. 20 refs., 5 figs.