4,986 research outputs found

    Project {\tt SANC} (former {\tt CalcPHEP}): Support of Analytic and Numeric calculations for experiments at Colliders

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    The project, aimed at the theoretical support of experiments at modern and future accelerators -- TEVATRON, LHC, electron Linear Colliders (TESLA, NLC, CLIC) and muon factories, is presented. Within this project a four-level computer system is being created, which must automatically calculate, at the one-loop precision level the pseudo- and realistic observables (decay rates and event distributions) for more and more complicated processes of elementary particle interaction, using the principle of knowledge storing. It was already used for a recalculation of the EW radiative corrections for Atomic Parity Violation [1] and complete one-loop corrections for the process e+ettˉe^+ e^-\to t\bar{t} [2-4]; for the latter an, agreement up to 11 digits with FeynArts and the other results is found. The version of {\tt SANC} that we describe here is capable of automatically computing the decay rates and the distributions for the decays Z(H,W)ffˉZ(H,W)\to f\bar{f} in the one-loop approximation.Comment: 3 Latex, Presented at ICHEP2002, Amsterdam, July 24-30, 2000; Submitted to Proceeding

    ZFITTER v.6.21 - A Semi-Analytical Program for Fermion Pair Production in e+e- Annihilation

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    We describe ZFITTER, a Fortran program based on a semi-analytical approach to fermion pair production in e+e- annihilation at a wide range of centre-of-mass energies, including the PETRA, TRISTAN, LEP1/SLC, and LEP2 energies. A flexible treatment of complete O(alpha) QED corrections and of some higher order contributions is made possible with three calculational chains containing different realistic sets of restrictions in the photon phase space. Numerical integrations are at most one-dimensional. Complete O(alpha) weak loop corrections supplemented by selected higher-order terms may be included. The program calculates Delta r, the Z width, differential cross-sections, total cross-sections, integrated forward-backward asymmetries, left-right asymmetries, and for tau pair production also final-state polarization effects. Various interfaces allow fits to be performed with different sets of free parameters.Comment: 200 pages, Latex2e, 26 figures, 4 tables; uses axodraw, epsfig, epsf, graphicx, espcrc1; typos of v.1 corrected, version for subm. to Comp. Phys. Commu

    GENTLE/4fan v.2.0 - A Program for the Semi-Analytic Calculation of Predictions for the Process e+e- -> 4f

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    We describe version 2.0 of the Fortran program GENTLE/4fan for the semi-analytic computation of cross-sections and distributions in four-fermion production in e+e- annihilation. GENTLE/4fan covers all charged current and neutral current our-fermion final states with no identical particles, no electrons, and no electron neutrinos in the final state. Initial state radiation representing the most relevant quantum corrections and anomalous triple gauge boson couplings have been included.Comment: 38 pages, LaTex, 4 tables, uses fleqn.sty and elsart.cl

    Radiative corrections to e+e- --> WW --> 4f with RACOONWW

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    RACOONWW is the first Monte Carlo generator for e+e- --> WW --> 4f(+gamma) that includes the electroweak O(alpha) radiative corrections in the double-pole approximation completely. Some numerical results for LEP2 energies are discussed, and the predictions for the total W-pair cross section are confronted with LEP2 data.Comment: 7 pages, latex, 5 postscript files, to appear in the Proceedings of the 5th Zeuthen Workshop on Elementary Particle Theory ``Loops and Legs in Quantum Field Theory'', Bastei/Koenigstein, Germany, April 9-14, 200

    Finite-width effects in the near-threshold ZZZ and ZWW production at ILC

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    We calculate the cross-section of the near-threshold off-shell ZZZZZZ and ZW+WZW^+W^- production at the International Linear Collider taking into account their instability and the principal part of NLO corrections. The calculations are performed in the framework of the model of unstable particles with smeared mass-shell. We show that the contribution of the finite Z/WZ/W and HH widths (their instability) is large in the Higgs resonance range and should be taken into account in the Higgs boson searches at future colliders.Comment: 5 pages, 6 figure

    ZFITTER: a semi-analytical program for fermion pair production in e+e- annihilation, from version 6.21 to version 6.42

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    ZFITTER is a Fortran program for the calculation of fermion pair production and radiative corrections at high energy e+e- colliders; it is also suitable for other applications where electroweak radiative corrections appear. ZFITTER is based on a semi-analytical approach to the calculation of radiative corrections in the Standard Model. We present a summary of new features of the ZFITTER program version 6.42 compared to version 6.21. The most important additions are: (i) some higher-order QED corrections to fermion pair production, (ii) electroweak one-loop corrections to atomic parity violation, (iii) electroweak one-loop corrections to nu-e nu-e-bar production, (iv) electroweak two-loop corrections to the W boson mass and the effective weak mixing angle.Comment: 60 pages, latex, 3 table

    The monstrosity of matter in Motion: Galileo, Descartes, and Hobbes’s political epistemology

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    Along the path opened by Galileo’s mechanics, early modern mechanical philosophy provided the metaphysical framework in which ‘matter in motion’ underwent a process of reduction to mathematical description and to physical explanation. The struggle against the monstrous contingency of matter in motion generated epistemological monsters in the domains of both the natural and civil sciences. In natural philosophy Descartes’ institution of Reason as a disembodied subject dominated the whole process. In political theory it was Hobbes who opposed the artificial unity of the body politic to the monstrous multiplicity of the multitude. Through a parallel analysis of the basic structure of Descartes’ and Hobbes’s enterprises, this article explains in which sense Hobbes’s peculiar form of materialism is in fact to be considered a surreptitious reduction of materialism to its ideological counterpart, Cartesian dualism, and to its implicit political-pedagogical project
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