686 research outputs found

    Farm Cost Account instructions and Code Manual

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    Noncommutative Geometry as a Regulator

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    We give a perturbative quantization of space-time R4R^4 in the case where the commutators CΌΜ=[XÎŒ,XÎœ]C^{{\mu}{\nu}}=[X^{\mu},X^{\nu}] of the underlying algebra generators are not central . We argue that this kind of quantum space-times can be used as regulators for quantum field theories . In particular we show in the case of the ϕ4{\phi}^4 theory that by choosing appropriately the commutators CΌΜC^{{\mu}{\nu}} we can remove all the infinities by reproducing all the counter terms . In other words the renormalized action on R4R^4 plus the counter terms can be rewritten as only a renormalized action on the quantum space-time QR4QR^4 . We conjecture therefore that renormalization of quantum field theory is equivalent to the quantization of the underlying space-time R4R^4 .Comment: Latex, 30 pages, no figures,typos corrected,references added . Substantial amount of rewriting of the last section . Final interesting remarks added at the end of the pape

    Reply to commentary by R Duggleby (2019)

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    Duggleby (2018) has made a numerical analysis of some aspects of the wide range of phenomena we reviewed in Steele et al. (2018) and asserted " .that panspermia as proposed by Steele et al. (2018) is extremely implausible.” It seems to us that Duggleby has based his viewpoint on a quite narrow and specific model of Panspermia which he supposes to be active in the cosmos. Here we address both his conclusions and his numerical analysis. Our response therefore will be at two levels, his specific analysis and his general conclusions. In the specific section below we show that while Duggleby's numerical analysis appears in part correct it is, in the final analysis, quite irrelevant to Cosmic Panspermia. In the general response which follows we address his unsupported conclusion throughout his critique, namely that 
 " none of the examples mentioned by Steele et al. (2018) is decisive enough to allow no other explanation.

    Grain Surface Models and Data for Astrochemistry

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    AbstractThe cross-disciplinary field of astrochemistry exists to understand the formation, destruction, and survival of molecules in astrophysical environments. Molecules in space are synthesized via a large variety of gas-phase reactions, and reactions on dust-grain surfaces, where the surface acts as a catalyst. A broad consensus has been reached in the astrochemistry community on how to suitably treat gas-phase processes in models, and also on how to present the necessary reaction data in databases; however, no such consensus has yet been reached for grain-surface processes. A team of ∌25 experts covering observational, laboratory and theoretical (astro)chemistry met in summer of 2014 at the Lorentz Center in Leiden with the aim to provide solutions for this problem and to review the current state-of-the-art of grain surface models, both in terms of technical implementation into models as well as the most up-to-date information available from experiments and chemical computations. This review builds on the results of this workshop and gives an outlook for future directions

    Delinquency and reputational orientations of adolescent at-risk and not-at-risk males and females

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    This research investigated differences in delinquent activities and the reputational orientations of at-risk and not-at-risk male and female adolescents. Initially, we sought to establish that adolescent males and females differed in these respects. This was found to be the case: males (n = 722) scored significantly higher than females (n = 738) on seven self-reported delinquency variables and on eight reputation enhancement variables pertaining to social deviance, non-conforming reputation, and power/evaluation private identity. When a sample of 31 at-risk females was subsequently pair-wise age matched with 31 not-at-risk females, at-risk females scored significantly higher on all delinquency variables other than school misdemeanors. These at-risk females also scored significantly higher on four reputation enhancement variables relating to social deviance and non-conformity. Given that at-risk females did not differ from their not-at-risk counterparts in level of involvement in school misdemeanors, we sought to determine whether this was also the case for at-risk and not-at-risk males. An age-matched sample of 91 pairs revealed that at-risk males reported significantly higher involvement than not-at-risk males in all aspects of delinquency, including school misdemeanors. They also sought a more non-conforming reputation. To explore the relationships between delinquency and reputation enhancement, a canonical correlation analysis was performed. All findings are discussed in the light of reputation enhancement theory. © 2008 Taylor & Franci

    Measurement of the B0-anti-B0-Oscillation Frequency with Inclusive Dilepton Events

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    The B0B^0-Bˉ0\bar B^0 oscillation frequency has been measured with a sample of 23 million \B\bar B pairs collected with the BABAR detector at the PEP-II asymmetric B Factory at SLAC. In this sample, we select events in which both B mesons decay semileptonically and use the charge of the leptons to identify the flavor of each B meson. A simultaneous fit to the decay time difference distributions for opposite- and same-sign dilepton events gives Δmd=0.493±0.012(stat)±0.009(syst)\Delta m_d = 0.493 \pm 0.012{(stat)}\pm 0.009{(syst)} ps−1^{-1}.Comment: 7 pages, 1 figure, submitted to Physical Review Letter

    Search for direct production of charginos and neutralinos in events with three leptons and missing transverse momentum in √s = 7 TeV pp collisions with the ATLAS detector

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    A search for the direct production of charginos and neutralinos in final states with three electrons or muons and missing transverse momentum is presented. The analysis is based on 4.7 fb−1 of proton–proton collision data delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with Standard Model expectations in three signal regions that are either depleted or enriched in Z-boson decays. Upper limits at 95% confidence level are set in R-parity conserving phenomenological minimal supersymmetric models and in simplified models, significantly extending previous results

    Jet size dependence of single jet suppression in lead-lead collisions at sqrt(s(NN)) = 2.76 TeV with the ATLAS detector at the LHC

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    Measurements of inclusive jet suppression in heavy ion collisions at the LHC provide direct sensitivity to the physics of jet quenching. In a sample of lead-lead collisions at sqrt(s) = 2.76 TeV corresponding to an integrated luminosity of approximately 7 inverse microbarns, ATLAS has measured jets with a calorimeter over the pseudorapidity interval |eta| < 2.1 and over the transverse momentum range 38 < pT < 210 GeV. Jets were reconstructed using the anti-kt algorithm with values for the distance parameter that determines the nominal jet radius of R = 0.2, 0.3, 0.4 and 0.5. The centrality dependence of the jet yield is characterized by the jet "central-to-peripheral ratio," Rcp. Jet production is found to be suppressed by approximately a factor of two in the 10% most central collisions relative to peripheral collisions. Rcp varies smoothly with centrality as characterized by the number of participating nucleons. The observed suppression is only weakly dependent on jet radius and transverse momentum. These results provide the first direct measurement of inclusive jet suppression in heavy ion collisions and complement previous measurements of dijet transverse energy imbalance at the LHC.Comment: 15 pages plus author list (30 pages total), 8 figures, 2 tables, submitted to Physics Letters B. All figures including auxiliary figures are available at http://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/HION-2011-02

    Measurement of the polarisation of W bosons produced with large transverse momentum in pp collisions at sqrt(s) = 7 TeV with the ATLAS experiment

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    This paper describes an analysis of the angular distribution of W->enu and W->munu decays, using data from pp collisions at sqrt(s) = 7 TeV recorded with the ATLAS detector at the LHC in 2010, corresponding to an integrated luminosity of about 35 pb^-1. Using the decay lepton transverse momentum and the missing transverse energy, the W decay angular distribution projected onto the transverse plane is obtained and analysed in terms of helicity fractions f0, fL and fR over two ranges of W transverse momentum (ptw): 35 < ptw < 50 GeV and ptw > 50 GeV. Good agreement is found with theoretical predictions. For ptw > 50 GeV, the values of f0 and fL-fR, averaged over charge and lepton flavour, are measured to be : f0 = 0.127 +/- 0.030 +/- 0.108 and fL-fR = 0.252 +/- 0.017 +/- 0.030, where the first uncertainties are statistical, and the second include all systematic effects.Comment: 19 pages plus author list (34 pages total), 9 figures, 11 tables, revised author list, matches European Journal of Physics C versio
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