Next-to-next-to-leading order O(αs4){\cal O}(\alpha_s^4) results for heavy quark pair production in quark--antiquark collisions: The one-loop squared contributions

We calculate the next-to-next-to-leading order ${\cal O}(\alpha_s^4)$ one-loop squared corrections to the production of heavy quark pairs in quark-antiquark annihilations. These are part of the next-to-next-to-leading order ${\cal O}(\alpha_s^4)$ radiative QCD corrections to this process. Our results, with the full mass dependence retained, are presented in a closed and very compact form, in the dimensional regularization scheme. We have found very intriguing factorization properties for the finite part of the amplitudes.Comment: 12 pages, 2 figures, electronic results file, abbreviation NNLO in Title and Abstract expanded, Summary expanded, reference updated, version to appear in Phys.Rev.

One-loop amplitudes for four-point functions with two external massive quarks and two external massless partons up to O(epsilon^2)

We present complete analytical ${\mathcal O}(\epsilon^2)$ results on the one-loop amplitudes relevant for the NNLO quark-parton model description of the hadroproduction of heavy quarks as given by the so-called loop-by-loop contributions. All results of the perturbative calculation are given in the dimensional regularization scheme. These one-loop amplitudes can also be used as input in the determination of the corresponding NNLO cross sections for heavy flavor photoproduction, and in photon-photon reactions.Comment: 25 pages, 6 figures in the text, Revtex, one reference added, minor improvements in the text, to appear in Phys.Rev.

The effects of a modest dose of alcohol on executive functioning and prospective memory

Rationale Acute alcohol intoxication selectively impairs executive functioning and prospective memory (PM). Much previous researches in this area have used laboratory-based tasks that may not mimic functions that individuals with dysexecutive syndrome have problems with in their everyday life. The present study aimed to assess the effects of a modest dose of alcohol on executive functioning and PM using a virtual reality task and investigate the role of executive planning in PM performance. Methods Forty healthy participants were administered 0.4 g/kg alcohol or matched placebo in a double-blind design. Executive function and PM were assessed using the Jansari–Agnew–Akesson–Murphy (JAAM) task, requiring participants to play the role of an office worker. Results Alcohol intoxication selectively impaired executive function and PM. The participants in the alcohol condition performed worse on the planning, prioritisation, creativity and adaptability executive subscales and also on the time-based and event-based PM tasks. However, alcohol did not impair the selection executive function task or the action-based PM task. Conclusions The results provide further support for the effects of alcohol on executive functioning and PM. In addition, the results suggest that such deficits may be present at relatively modest doses of alcohol and in the absence of a subjective feeling of intoxication Keywords: alcohol; executive functioning; prospective memory; virtual reality; memor

Discrimination and the Implicit Association Test

Prejudice researchers have been criticized for failing to assess behaviors that reflect overtly hostile actions (i.e. racial animus; Arkes & Tetlock, 2004; Mackie & Smith, 1998). Two studies sought to begin to fill this gap in the implicit literature by showing that scores on the Implicit Association Test (IAT; Greenwald, McGhee, & Schwartz, 1998) are linked to harmful intergroup behaviors. In Study 1, the IAT predicted self-reported racial discrimination, including verbal slurs, exclusion, and physical harm. In Study 2, the IAT predicted recommended budget cuts for Jewish, Asian, and Black student organizations (i.e. economic discrimination). In each study, evaluative stereotype (but not attitude) IATs predicted behaviors even after controlling for explicit attitudes. In concert, the findings suggest that implicit stereotypes are more predictive of overtly harmful actions than implicit attitudes in the intergroup relations domain

Atom detection and photon production in a scalable, open, optical microcavity

A microfabricated Fabry-Perot optical resonator has been used for atom detection and photon production with less than 1 atom on average in the cavity mode. Our cavity design combines the intrinsic scalability of microfabrication processes with direct coupling of the cavity field to single-mode optical waveguides or fibers. The presence of the atom is seen through changes in both the intensity and the noise characteristics of probe light reflected from the cavity input mirror. An excitation laser passing transversely through the cavity triggers photon emission into the cavity mode and hence into the single-mode fiber. These are first steps towards building an optical microcavity network on an atom chip for applications in quantum information processing.Comment: 4 pages, 4 figures. A typographical error in the published paper has been corrected (equation of the corrected normalized variance, page 3, 2nd paragraph