The relationship between the viscosity and the dc-conductivity in polyvinylchloride

Relation between viscosity and direct current conductivity in polyvinyl chlorid

NLO QCD corrections to W+ W+ jj production in vector-boson fusion at the LHC

We present a next-to-leading-order QCD calculation for e+\nu e\mu+\nu\mu jj production in vector-boson fusion, i.e. the scattering of two positively charged W bosons at the LHC. We include the complete set of electroweak leading-order diagrams for the six-particle final state and quantitatively assess the size of the s-channel and interference contributions in VBF kinematics. The calculation uses the complex-mass scheme to describe the W-boson resonances and is implemented into a flexible Monte Carlo generator. Using a dynamical scale based on the transverse momenta of the jets, the QCD corrections stay below about 10% for all considered observables, while the residual scale dependence is at the level of 1%.Comment: 60 page

Wgamma and Zgamma production at the LHC in NNLO QCD

We consider the production of $W\gamma$ and $Z\gamma$ pairs at hadron colliders. We report on the complete fully differential computation of radiative corrections at next-to-next-to-leading order (NNLO) in QCD perturbation theory. The calculation includes the leptonic decay of the vector boson with the corresponding spin correlations, off shell effects and final-state photon radiation. We present numerical results for $pp$ collisions at 7 and 8 TeV and we compare them with available LHC data. In the case of $Z\gamma$ production, the impact of NNLO corrections is generally moderate, ranging from 8% to 18%, depending on the applied cuts. In the case of $W\gamma$ production, the NNLO effects are more important, and range from 19% to 26%, thereby improving the agreement of the theoretical predictions with the data. As expected, the impact of QCD radiative corrections is significantly reduced when a jet veto is applied.Comment: 27 pages, 11 figure

A unified NLO description of top-pair and associated Wt production

We present an NLO simulation of WWbb production with massive b-quarks at the LHC. Off-shell and non-resonant contributions associated with top-pair and single-top channels and with leptonic W-boson decays are consistently taken into account using the complex-mass scheme. Thanks to the finite b-quark mass, WWbb predictions can be extended to the whole b-quark phase space, thereby including Wt-channel single-top contributions that originate from collinear g->bb splittings in the four-flavour scheme. This provides a consistent NLO description of tt and Wt production and decay, including quantum interference effects. The simulation is also applicable to exclusive 0- and 1-jet bins, which is of great importance for Higgs-boson studies in the H->WW channel and for any other analysis with large top backgrounds and jet vetoes or jet bins.Comment: 8pp. Minor revision, results unchange

W±ZW^\pm Z production at the LHC: fiducial cross sections and distributions in NNLO QCD

We report on the first fully differential calculation for $W^\pm Z$ production in hadron collisions up to next-to-next-to-leading order (NNLO) in QCD perturbation theory. Leptonic decays of the $W$ and $Z$ bosons are consistently taken into account, i.e. we include all resonant and non-resonant diagrams that contribute to the process $pp\to \ell^{'\pm} \nu_{\ell^{'}} \ell^+\ell^-+X$ both in the same-flavour ($\ell'=\ell$) and the different-flavour ($\ell'\neq \ell$) channel. Fiducial cross sections and distributions are presented in the presence of standard selection cuts applied in the experimental $W^\pm Z$ analyses by ATLAS and CMS at centre-of-mass energies of 8 and 13\,TeV. As previously shown for the inclusive cross section, NNLO corrections increase the NLO result by about $10\%$, thereby leading to an improved agreement with experimental data. The importance of NNLO accurate predictions is also shown in the case of new-physics scenarios, where, especially in high-$p_T$ categories, their impact can reach ${\cal O}(20\%)$. The availability of differential NNLO predictions will play a crucial role in the rich physics programme that is based on precision studies of $W^\pm Z$ signatures at the LHC.Comment: 38 pages, 18 figures, 8 table

Studienvoraussetzungen prüfen – Der StudiCheck Mathematik in NRW

Viele Studiengänge bemängeln, dass StudienanfängerInnen nicht die nötigen Vorkenntnisse mitbringen, die für einen erfolgreichen Studienstart notwendig sind. Besonders häufig werden Defizite in Mathematik beklagt. Seit August 2013 haben Studieninteressierte über das Orientierungsportal StudiFinder die Möglichkeit, ihr Vorwissen in 18 Gebieten der Schulmathematik zu überprüfen. Hierbei kann jeder Studiengang einer Hochschule in NRW individuell relevante Tests zusammenstellen sowie Rückmeldungen und Schwellenwerte festlegen

Fully differential NNLO computations with MATRIX

We present the computational framework MATRIX which allows us to evaluate fully differential cross sections for a wide class of processes at hadron colliders in next-to-next-to-leading order (NNLO) QCD. The processes we consider are $2\to 1$ and $2\to 2$ hadronic reactions involving Higgs and vector bosons in the final state. All possible leptonic decay channels of the vector bosons are included for the first time in the calculations, by consistently accounting for all resonant and non-resonant diagrams, off-shell effects and spin correlations. We briefly introduce the theoretical framework MATRIX is based on, discuss its relevant features and provide a detailed description of how to use MATRIX to obtain NNLO accurate results for the various processes. We report reference predictions for inclusive and fiducial cross sections of all the physics processes considered here and discuss their corresponding uncertainties. MATRIX features an automatic extrapolation procedure that allows us, for the first time, to control the systematic uncertainties inherent to the applied NNLO subtraction procedure down to the few permille level (or better).Comment: 76 pages, 2 figures, 11 table