Revisiting the global electroweak fit of the Standard Model and beyond with Gfitter

The global fit of the Standard Model to electroweak precision data, routinely performed by the LEP electroweak working group and others, demonstrated impressively the predictive power of electroweak unification and quantum loop corrections. We have revisited this fit in view of (i) the development of the new generic fitting package, Gfitter, allowing for flexible and efficient model testing in high-energy physics, (ii) the insertion of constraints from direct Higgs searches at LEP and the Tevatron, and (iii) a more thorough statistical interpretation of the results. Gfitter is a modular fitting toolkit, which features predictive theoretical models as independent plug-ins, and a statistical analysis of the fit results using toy Monte Carlo techniques. The state-of-the-art electroweak Standard Model is fully implemented, as well as generic extensions to it. Theoretical uncertainties are explicitly included in the fit through scale parameters varying within given error ranges. This paper introduces the Gfitter project, and presents state-of-the-art results for the global electroweak fit in the Standard Model (SM), and for a model with an extended Higgs sector (2HDM). Numerical and graphical results for fits with and without including the constraints from the direct Higgs searches at LEP and Tevatron are given. Perspectives for future colliders are analysed and discussed. In the SM fit including the direct Higgs searches, we find M _H =116.4_−1.3^+18.3 GeV, and the 2σ and 3σ allowed regions [114,145] GeV and [[113,168] and [180,225]] GeV, respectively. For the strong coupling strength at fourth perturbative order we obtain α _S (M _Z ²)=0.1193_−0.0027^+0.0028(exp )±0.0001 (theo). Finally, for the mass of the top quark, excluding the direct measurements, we find m _t =178.2_−4.2^+9.8 GeV. In the 2HDM we exclude a charged-Higgs mass below 240 GeV at 95% confidence level. This limit increases towards larger tan β, e.g., is excluded for tan β=70.     

One Decade of Microwave‐Assisted Polymerizations: Quo vadis?

The application of microwave irradiation in polymer syntheses and modifications is of continuously growing interest and has received significant international interest since the beginning of the millennium. Preceded by a review that was published 6 years ago, the present paper summarizes the most recent trends in this research area. Radical as well as step‐growth and ring‐opening polymerizations will be addressed; furthermore, the evolution from microwave‐assisted polymerizations to microwave‐assisted material fabrication will be described on the examples of polymeranalogous reactions, polymer/metal composites and bio‐based materials.

     

Resolution enhancement in a light-sheet-based microscope (SPIM)

Light-sheet-based microscopy [single-plane illumination microscope (SPIM)] performs very well at low numerical apertures. It complements conventional (FM), confocal (CFM), and two-photon fluorescence microscopy (2hnu-FM) currently used in modern life sciences. Lateral and axial SPIM point spread function (PSF) extents are measured by using fluorescent beads to determine the 3D resolution. The results are compared with values derived from an analytical theory and numerical simulations. The discrepancies are found to be less than 5%. The axial extent of a SPIM-PSF (10x/0.3 W) is approximately 5.7 microm. This value is almost a factor of 2 smaller than in CFM, more than 2.5 times smaller than in FM, and more than three times smaller than in 2hnu-FM. SPIM outperforms 2hnu-FM and FM, while CFM has a better axial resolution at NAs above 0.8.     

Purity and homotopy theory of coalgebras

We construct a combinatorical monoidal model category on simplicial flat cocommutative coalgebras over a Prüfer domain. The cofibrations are the morphisms which are pure as module maps.     

Reaction of Methylene Bridged Diphosphines R2P-CH2-PRH AND RHP-CH2-PRH (R [dbnd] Me,Pri, But,CH2-Ph) with Transition Metal Carbonyls

Abstract

The PH-functional methylene bridged diphosphines R₂P-CH₂-PRH and RHP-CH₂-PHR have been synthesized using Cl₂P-CH₂-PCl₂ as a starting material. On reaction with Fe₂(CO)₉ oxidative addition and cleavage of the P-C-P-skeleton occur yielding cluster compounds, e. g. (CO)₉Fe₃(RR 'P-CH₂-PR)H (R [dbnd] Me, Prⁱ, Bu^t, CH₂-Ph, R' [dbnd] R or H) or (CO)₉Fe₃(μ₃PR)(μ₂PMeR)H.     

Solution Structure and Reactions of Lithium-Organophosphido Complexes

Abstract

Transition metal carbonyl complexes of phosphine (PH₃), primary and secondary phosphines may be deprotonated with methyllithium to give the lithiated derivatives (I, II) which were shown to be useful intermediates in template synthesis of unusual phosphorus ligands [1].     

Trends in Ring-Opening Metathesis Polymerization

Abstract

Several transition metal alkylidene complexes are first discussed as catalysts for the ring-opening metathesis reaction. A new ruthenium catalyst with a slightly enhanced reaction rate is introduced. The stereochemistry and kinetics of the catalysts are investigated with different norbornene derivatives. Then it is shown that MgCl₂ alone is a good heterogeneous catalyst for the ring-opening polymerization (ROMP) of norbornene compounds. This is the first catalyst which does not need activation by a transition metal compound or another organometallic cocatalyst. Applications of the ROMP reaction for the synthesis of polymer specialities covering conjugated liquid crystals and optically active polymers are shown. Poly(cyclopentadienylene vinylene) and sidechain liquid crystal polymers are discussed in more detail. Finally, the synthesis of liquid crystalline elastomers by incorporation of bifunctional monomers during the ROMP reaction is described. It is shown that this kind of polymer can be used for the fabrication of optically anisotropic materials.     

Multivariate CARMA processes

A multivariate Lévy-driven continuous time autoregressive moving average (CARMA) model of order (p,q$p,q$), q<p$q<p$, is introduced. It extends the well-known univariate CARMA and multivariate discrete time ARMA models. We give an explicit construction using a state space representation and a spectral representation of the driving Lévy process. Furthermore, various probabilistic properties of the state space model and the multivariate CARMA process itself are discussed in detail.     

Modification Pathways for Copoly(2‐oxazoline)s Enabling Their Application as Antireflective Coatings in Photolithography

Chromophore‐functionalized copoly(2‐oxazoline)s are successfully evaluated as bottom antireflective coatings (BARCs) in high‐resolution photolithography. With respect to UV light sources used in photolithographic production routines, anthracene is chosen as a chromophore. For application as polymer in BARCs, the copolymer poly(2‐ethyl‐2‐oxazolin)₄₅‐stat‐poly(2‐dec‐9′‐enyl‐2‐oxazolin)₂₀‐stat‐poly(2‐(3′‐(1″‐(anthracen‐9‐ylmethyl)‐1″,2″,3″‐triazol‐4‐yl)propyl)‐2‐oxazolin)₃₅ can be synthesized by the Huisgen cycloaddition click reaction of the copolymer poly(2‐ethyl‐2‐oxazolin)₄₅‐stat‐poly(2‐dec‐9′‐enyl‐2‐oxazolin)₂₀‐stat‐poly(2‐pent‐4′‐inyl‐2‐oxazolin)₃₅ and the corresponding azide‐functionalized anthracenes. These copolymers can be crosslinked by the thermally induced thiol‐ene reaction involving the unsaturated C=C bonds of the poly(2‐dec‐9′‐enyl‐2‐oxazoline) repetition units and a multifunctional thiol as crosslinker. Tests of this BARC in a clean room under production conditions reveal a significant decrease of the swing‐curve of a chemically amplified positive photoresist by more than 50%, hence significantly increasing the resolution of the photoresist.