163 research outputs found

    Hadronic Higgs Production and Decay in Supersymmetry at Next-to-Leading Order

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    Supersymmetric QCD corrections to the gluonic production and decay rate of a CP-even Higgs boson are evaluated at next-to-leading order. To this aim, we derive an effective Lagrangian for the gluon-Higgs coupling. We show that a consistent calculation requires the inclusion of gluino effects, in contrast to what has been done previously. The supersymmetric corrections to the gluon-Higgs coupling lead to a modification of the next-to-leading order K-factor for the Higgs production rate at the LHC by less than five percent.Comment: 13 pages, LaTeX, 12 ps-files included. v2: Typos fixed, references added, minor modifications. v3: Typos fixed

    Dimensional Reduction applied to QCD at three loops

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    Dimensional Reduction is applied to \qcd{} in order to compute various renormalization constants in the \drbar{} scheme at higher orders in perturbation theory. In particular, the ÎČ\beta function and the anomalous dimension of the quark masses are derived to three-loop order. Special emphasis is put on the proper treatment of the so-called Ï”\epsilon-scalars and the additional couplings which have to be considered.Comment: 13 pages, minor changes, references adde

    Safe Autonomous Driving in Adverse Weather: Sensor Evaluation and Performance Monitoring

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    The vehicle's perception sensors radar, lidar and camera, which must work continuously and without restriction, especially with regard to automated/autonomous driving, can lose performance due to unfavourable weather conditions. This paper analyzes the sensor signals of these three sensor technologies under rain and fog as well as day and night. A data set of a driving test vehicle as an object target under different weather conditions was recorded in a controlled environment with adjustable, defined, and reproducible weather conditions. Based on the sensor performance evaluation, a method has been developed to detect sensor degradation, including determining the affected data areas and estimating how severe they are. Through this sensor monitoring, measures can be taken in subsequent algorithms to reduce the influences or to take them into account in safety and assistance systems to avoid malfunctions.Comment: Accepted for the 35th IEEE Intelligent Vehicles Symposium (IV 2023), 6 page

    Four-loop beta function and mass anomalous dimension in Dimensional Reduction

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    Within the framework of QCD we compute renormalization constants for the strong coupling and the quark masses to four-loop order. We apply the DR-bar scheme and put special emphasis on the additional couplings which have to be taken into account. This concerns the epsilon-scalar--quark Yukawa coupling as well as the vertex containing four epsilon-scalars. For a supersymmetric Yang Mills theory, we find, in contrast to a previous claim, that the evanescent Yukawa coupling equals the strong coupling constant through three loops as required by supersymmetry.Comment: 15 pages, fixed typo in Eq. (18

    Rhad: A program for the evaluation of the hadronic R-ratio in the perturbative regime of QCD

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    This paper describes the fortran program rhad which performs a numerical evaluation of the photon-induced hadronic R-ratio, R(s), related to the cross section for electron-positron annihilation, for a given center-of-mass energy \sqrt{s}. In rhad the state-of-the-art perturbative corrections to R(s) are implemented and the running and decoupling of the strong coupling constant and the quark masses is automatically treated consistently. Several options allow for a flexible use of the program.Comment: 40 pages, LaTeX. 18 ps-files included. Typos fixed, references updated. The program and this paper are available from http://www.rhad.de

    The four-loop N = 4 SYM Sudakov form factor

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    We present the Sudakov form factor in full color N = 4 supersymmetric Yang- Mills theory to four loop order and provide uniformly transcendental results for the relevant master integrals through to weight eight

    Macrophage/fibroblast coculture induces macrophage inflammatory protein‐1a production mediated by intercellular adhesion molecule‐1 and oxygen radicals

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    This study examined the cell‐to‐cell interaction between fibroblasts and macrophages as a possible contributor to the chronic inflammatory state. In a coculture system, consisting of macrophages layered over confluent fibroblasts, there was a significant increase in macrophage inflammatory protein 1α (MIP‐1α) compared with control cultures. ICAM‐1 adhesion was identified as an important stimulus of MIP‐1α production by using ICAM‐1‐specific monoclonal antibodies. Furthermore, fibroblasts from ICAM‐1 knockout mice induced significantly less MIP‐1α production from peritoneal macrophages when compared to control fibroblasts. In addition, it appeared that oxygen radicals functioned as activating molecules during cellular interaction and production of MIP‐1α, as the addition of the antioxidant N‐acetylcysteine (NAC) prevented MIP‐1α secretion. Thus, the ICAM‐1 and oxygen radical‐mediated induction of MIP‐1α associated with a macrophage/fibroblast coculture system provides one possible mechanism by which immune/inflammatory cell interactions may augment chemokine production and exacerbate chronic inflammatory diseases. J. Leukoc. Biol. 64: 636–641; 1998.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141120/1/jlb0636.pd

    Fermionic corrections to quark and gluon form factors in four-loop QCD

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    We analytically compute all four-loop QCD corrections to the photon-quark and Higgs-gluon form factors involving a closed massless fermion loop. Our calculation of nonplanar vertex integrals confirms a previous conjecture for the analytical form of the nonfermionic contributions to the collinear anomalous dimensions of quarks and gluons
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