Chemical shifts in 1H and 13C NMR spectra of Alkyl- and Arylalkylureas

The paper dwells on the 1H and 13C spectra of the N-aryl- and N-arylalkylureas. The effects of the aryland arylalkyl- substituents on the chemical shifts are mutually compared, as well as correlated with the corresponding effects for methylureas. Correlations between methanetriyl group's carbon Δδ's and steric factors are discussed briefly. The neighboring group influence on aromatic carbon's chemical shifts has proven to be insignificant. Comparative analysis of the 1H spectra allowed us to describe the differences between effects of various substituents on the amino proton shieldings

Zusammenhänge zwischen Unternehmensverflechtungen und -gewinnen, Rekrutierung von Führungskräften und deren Einkommenssituation: (Literaturstudie)

"Die Armuts- und Reichtumsberichte der Bundesregierung orientieren sich an Amartya Sens Konzept der Verwirklichungschancen und richten dabei ihr Augenmerk ebenso auf den Reichtum als hohes Maß an Verwirklichungschancen. Um insbesondere Forschungsdefizite in Bezug auf Reichtum abzubauen, sollten in einer Literaturstudie die vorliegenden Untersuchungen zum Zusammenhang zwischen der Gewinnsituation von Unternehmen, der Einkommenserzielung von Führungskräften und den Mechanismen zur Rekrutierung der Führungseliten großer Publikumsaktiengesellschaften dargestellt werden. Dementsprechend soll diese Studie im Auftrag des Bundesministeriums für Arbeit und Soziales einerseits dokumentieren, welche Zusammenhänge zwischen dem intensivierten globalen Wettbewerb auf Güter- und Faktormärkten und den Rekrutierungsprozessen sowie Entlohnungssystemen im deutschen Top-Management bestehen. Andererseits stehen sozioökonomische Privilegierungen beim Aufstieg in Spitzenpositionen der deutschen Wirtschaft zur Diskussion. Nicht zuletzt sollen Bezüge für eine Integration solcher Fragenkreise in die Konzeption der Verwirklichungschancen aufgezeigt werden. Nach ersten Ausgangsüberlegungen in Teil A erörtern wir im vorliegenden Bericht zunächst den Einfluss globaler Wettbewerbsprozesse auf Spielraum und Entlohnung von Spitzenmanagern großer deutscher Unternehmen. In Teil C diskutieren wir Stellenwert und Ursachen von sozioökonomischen Zugangsbeschränkungen und ungleichen Chancen beim Aufstieg in Spitzenfunktionen. Teil D stellt Verknüpfungen mit dem Konzept der Verwirklichungschancen her und bindet die Ergebnisse in das Konzept ein. Ein Ausblick, auch auf die Konsequenzen der künftigen Armuts- und Reichtumsberichterstattung, schließt die Überlegungen ab. Unser Anliegen war es, ökonomische und andere sozialwissenschaftliche Herangehensweisen gleichermaßen aufzugreifen, die in diesem Kontext nur selten gemeinsam Beachtung finden." (Autorenreferat

Study of doubly strange systems using stored antiprotons

Bound nuclear systems with two units of strangeness are still poorly known despite their importance for many strong interaction phenomena. Stored antiprotons beams in the GeV range represent an unparalleled factory for various hyperon-antihyperon pairs. Their outstanding large production probability in antiproton collisions will open the floodgates for a series of new studies of systems which contain two or even more units of strangeness at the P‾ANDA experiment at FAIR. For the first time, high resolution γ-spectroscopy of doubly strange ΛΛ-hypernuclei will be performed, thus complementing measurements of ground state decays of ΛΛ-hypernuclei at J-PARC or possible decays of particle unstable hypernuclei in heavy ion reactions. High resolution spectroscopy of multistrange Ξ−-atoms will be feasible and even the production of Ω−-atoms will be within reach. The latter might open the door to the |S|=3 world in strangeness nuclear physics, by the study of the hadronic Ω−-nucleus interaction. For the first time it will be possible to study the behavior of Ξ‾+ in nuclear systems under well controlled conditions

Measurement of the top quark forward-backward production asymmetry and the anomalous chromoelectric and chromomagnetic moments in pp collisions at √s = 13 TeV

Abstract The parton-level top quark (t) forward-backward asymmetry and the anomalous chromoelectric (d̂ t) and chromomagnetic (μ̂ t) moments have been measured using LHC pp collisions at a center-of-mass energy of 13 TeV, collected in the CMS detector in a data sample corresponding to an integrated luminosity of 35.9 fb−1. The linearized variable AFB(1) is used to approximate the asymmetry. Candidate t t ¯ events decaying to a muon or electron and jets in final states with low and high Lorentz boosts are selected and reconstructed using a fit of the kinematic distributions of the decay products to those expected for t t ¯ final states. The values found for the parameters are AFB(1)=0.048−0.087+0.095(stat)−0.029+0.020(syst),μ̂t=−0.024−0.009+0.013(stat)−0.011+0.016(syst), and a limit is placed on the magnitude of | d̂ t| < 0.03 at 95% confidence level. [Figure not available: see fulltext.

MUSiC : a model-unspecific search for new physics in proton-proton collisions at root s=13TeV

Results of the Model Unspecific Search in CMS (MUSiC), using proton-proton collision data recorded at the LHC at a centre-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 35.9 fb(-1), are presented. The MUSiC analysis searches for anomalies that could be signatures of physics beyond the standard model. The analysis is based on the comparison of observed data with the standard model prediction, as determined from simulation, in several hundred final states and multiple kinematic distributions. Events containing at least one electron or muon are classified based on their final state topology, and an automated search algorithm surveys the observed data for deviations from the prediction. The sensitivity of the search is validated using multiple methods. No significant deviations from the predictions have been observed. For a wide range of final state topologies, agreement is found between the data and the standard model simulation. This analysis complements dedicated search analyses by significantly expanding the range of final states covered using a model independent approach with the largest data set to date to probe phase space regions beyond the reach of previous general searches.Peer reviewe

Search for new particles in events with energetic jets and large missing transverse momentum in proton-proton collisions at root s=13 TeV

A search is presented for new particles produced at the LHC in proton-proton collisions at root s = 13 TeV, using events with energetic jets and large missing transverse momentum. The analysis is based on a data sample corresponding to an integrated luminosity of 101 fb(-1), collected in 2017-2018 with the CMS detector. Machine learning techniques are used to define separate categories for events with narrow jets from initial-state radiation and events with large-radius jets consistent with a hadronic decay of a W or Z boson. A statistical combination is made with an earlier search based on a data sample of 36 fb(-1), collected in 2016. No significant excess of events is observed with respect to the standard model background expectation determined from control samples in data. The results are interpreted in terms of limits on the branching fraction of an invisible decay of the Higgs boson, as well as constraints on simplified models of dark matter, on first-generation scalar leptoquarks decaying to quarks and neutrinos, and on models with large extra dimensions. Several of the new limits, specifically for spin-1 dark matter mediators, pseudoscalar mediators, colored mediators, and leptoquarks, are the most restrictive to date.Peer reviewe

Measurement of prompt open-charm production cross sections in proton-proton collisions at root s=13 TeV

The production cross sections for prompt open-charm mesons in proton-proton collisions at a center-of-mass energy of 13TeV are reported. The measurement is performed using a data sample collected by the CMS experiment corresponding to an integrated luminosity of 29 nb(-1). The differential production cross sections of the D*(+/-), D-+/-, and D-0 ((D) over bar (0)) mesons are presented in ranges of transverse momentum and pseudorapidity 4 < p(T) < 100 GeV and vertical bar eta vertical bar < 2.1, respectively. The results are compared to several theoretical calculations and to previous measurements.Peer reviewe

Combined searches for the production of supersymmetric top quark partners in proton-proton collisions at root s=13 TeV

A combination of searches for top squark pair production using proton-proton collision data at a center-of-mass energy of 13 TeV at the CERN LHC, corresponding to an integrated luminosity of 137 fb(-1) collected by the CMS experiment, is presented. Signatures with at least 2 jets and large missing transverse momentum are categorized into events with 0, 1, or 2 leptons. New results for regions of parameter space where the kinematical properties of top squark pair production and top quark pair production are very similar are presented. Depending on themodel, the combined result excludes a top squarkmass up to 1325 GeV for amassless neutralino, and a neutralinomass up to 700 GeV for a top squarkmass of 1150 GeV. Top squarks with masses from 145 to 295 GeV, for neutralino masses from 0 to 100 GeV, with a mass difference between the top squark and the neutralino in a window of 30 GeV around the mass of the top quark, are excluded for the first time with CMS data. The results of theses searches are also interpreted in an alternative signal model of dark matter production via a spin-0 mediator in association with a top quark pair. Upper limits are set on the cross section for mediator particle masses of up to 420 GeV