163 research outputs found
Hadronic Higgs Production and Decay in Supersymmetry at Next-to-Leading Order
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
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 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 -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
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
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
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
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 proteinâ1a production mediated by intercellular adhesion moleculeâ1 and oxygen radicals
This study examined the cellâtoâcell 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 (MIPâ1α) compared with control cultures. ICAMâ1 adhesion was identified as an important stimulus of MIPâ1α production by using ICAMâ1âspecific monoclonal antibodies. Furthermore, fibroblasts from ICAMâ1 knockout mice induced significantly less MIPâ1α 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 MIPâ1α, as the addition of the antioxidant Nâacetylcysteine (NAC) prevented MIPâ1α secretion. Thus, the ICAMâ1 and oxygen radicalâmediated induction of MIPâ1α 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: 636â641; 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
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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