Stable One-Dimensional Integral Representations of One-Loop N-Point Functions in the General Massive Case: I - Three Point Functions

In this article we provide representations for the one-loop three point functions in 4 and 6 dimensions in the general case with complex masses. The latter are part of the GOLEM library used for the computation of one-loop multileg amplitudes. These representations are one-dimensional integrals designed to be free of instabilites induced by inverse powers of Gram determinants, therefore suitable for stable numerical implementations.Comment: 40 pages, 1 figur

A full Next to Leading Order study of direct photon pair production in hadronic collisions

We discuss the production of photon pairs in hadronic collisions, from fixed target to LHC energies. The study which follows is based on a QCD calculation at full next-to-leading order accuracy, including single and double fragmentation contributions, and implemented in the form of a general purpose computer program of "partonic event generator" type. To illustrate the possibilities of this code, we present the comparison with observables measured by the WA70 and D0 collaborations, and some predictions for the irreducible background to the search of Higgs bosons at LHC in the channel $h \to \gamma \gamma$. We also discuss theoretical scale uncertainties for these predictions, and examine several infrared sensitive situations which deserve further study.Comment: 45 pages Latex, 16 eps files plus some metafont files; replaced by the version to appear in Eur. Phys. J.

Improving preschoolers\u27 memories for the sources of events: A comparison of two source-monitoring training techniques

Preschoolers have a tendency to confuse the sources of events when recalling information. Two source-monitoring training (SMT) techniques were compared to see whether source confusions can be reduced in 3- to 4-year-old children (N = 37). After watching a puppet-show and story, children were randomly assigned to one of three conditions: two SMT conditions (explicit and implicit) and one control condition (memory training) where they were trained on non-target puppet-show and story events. The explicit method consisted of a clear mention of both sources (story, puppet show) and their modality (hearing and seeing, respectively) during training, specific instruction to utilize the strategy during the target interview and a definition, and clear mention to beware of misleading questions. The implicit condition utilized a general mention of both sources (hear, see) as well as no mention of misleading questions or instruction to continue utilizing the strategy. Children in the control condition were not given source training, but rather were trained to recognize the presence of items in each event. No differences were found between conditions in response to yes-no questions. However planned comparisons revealed differences between the explicit and control groups with regards to source-recognition, with the explicit group performing more accurately with regards to identification. Children in the implicit group were more likely to respond \u27I don\u27t know\u27 in comparison to the control group with regards to open-ended questions. Implications for strategy development are discussed

A critical phenomenological study of inclusive photon production in hadronic collisions

We discuss fixed target and ISR inclusive photon production and attempt a comparison between theory and experiments. The dependence of the theoretical predictions on the structure functions, and on the renormalization and factorization scales is investigated. The main result of this study is that the data cannot be simultaneously fitted with a single set of scales and structure functions. On the other hand, there is no need for an additional intrinsic $k_{_T}$ to force the agreement between QCD predictions and experiments, with the possible exception of one data set. Since the data cover almost overlapping kinematical ranges this raises the question of consistency among data sets. A comparative discussion of some possible sources of experimental uncertainties is sketched.Comment: 22 pages, 3 tables, 10 figures, Late