In recent years, the Pirate Party of Sweden, the Wikimedia Foundation, the Debian project, the "Software in the Public Interest" project, the Gentoo project, and many other private organizations ...adopted a new single-winner election method for internal elections and referendums. In this article, we will introduce this method, demonstrate that it satisfies, e.g., resolvability, Condorcet, Pareto, reversal symmetry, monotonicity, and independence of clones and present an O(Ĉ3) algorithm to calculate the winner, where C is the number of alternatives.
We consider hadronic top quark pair production and pair production in association with a photon or a
Z
boson to probe electroweak dipole couplings in
t
b
¯
W
,
t
t
¯
γ
, and
t
t
¯
Z
interactions. We ...demonstrate how measurements of these processes at the 13 TeV LHC can be combined to disentangle and constrain anomalous dipole operators. The construction of cross section ratios allows us to significantly reduce various uncertainties and exploit orthogonal sensitivity between the
t
t
¯
γ
and
t
t
¯
Z
couplings. In addition, we show that angular correlations in
t
t
¯
production can be used to constrain the remaining
t
b
¯
W
dipole operator. Our approach yields excellent sensitivity to the anomalous couplings and can be a further step toward precise and direct measurements of the top quark electroweak interactions.
We present an extension of the JHUGen and MELA framework, which includes an event generator and library for the matrix element analysis. It enables simulation, optimal discrimination, reweighting ...techniques, and analysis of a bosonic resonance and the triple and quartic gauge boson interactions with the most general anomalous couplings. The new features, which become especially relevant at the current stage of LHC data taking, are the simulation of gluon fusion and vector boson fusion in the off-shell region, associated ZH production at NLO QCD including the gg initial state, and the simulation of a second spin-zero resonance. We also quote translations of the anomalous coupling measurements into constraints on dimension-six operators of an effective field theory. Some of the new features are illustrated with projections for experimental measurements with the full LHC and HL-LHC datasets.
The experimental determination of the properties of the newly discovered boson at the Large Hadron Collider is currently the most crucial task in high-energy physics. We show how information about ...the spin, parity, and, more generally, the tensor structure of the boson couplings can be obtained by studying angular and mass distributions of events in which the resonance decays to pairs of gauge bosons, ZZ, WW, and gamma gamma . A complete Monte Carlo simulation of the process pp arrow right X arrow right VV arrow right 4functionof is performed and verified by comparing it to an analytic calculation of the decay amplitudes X arrow right VV arrow right 4functionof. Our studies account for all spin correlations and include general couplings of a spin J = 0, 1, 2 resonance to Standard Model particles. We also discuss how to use angular and mass distributions of the resonance decay products for optimal background rejection. It is shown that by the end of the 8 TeV run of the LHC, it might be possible to separate extreme hypotheses of the spin and parity of the new boson with a confidence level of 99% or better for a wide range of models. We briefly discuss the feasibility of testing scenarios where the resonance is not a parity eigenstate.
The transverse momentum (pT) distribution of Higgs bosons at hadron colliders enables a detailed probe of its production dynamics and is a key ingredient to precision studies of Higgs boson ...properties, but receives very large QCD corrections. We obtain a precision prediction for the pT spectrum by matching second-order (NNLO) QCD corrections at large pT with resummation of third-order logarithmic (N3LL) corrections at small pT. We achieve significantly improved results for pT<35 GeV with perturbative uncertainties ≲±6%, and thus a convergent perturbative series for all values of pT.
Differentiated neurons established via iPSCs from patients that suffer from familial Parkinson's disease (PD) have allowed insights into the mechanisms of neurodegeneration. In the larger cohort of ...patients with sporadic PD, iPSC based information on disease specific cellular phenotypes is rare. We asked whether differences may be present on genomic and epigenomic levels and performed a comprehensive transcriptomic and epigenomic analysis of fibroblasts, iPSCs and differentiated neuronal cells of sporadic PD-patients and controls. We found that on mRNA level, although fibroblasts and iPSCs are largely indistinguishable, differentiated neuronal cells of sporadic PD patients show significant alterations enriched in pathways known to be involved in disease aetiology, like the CREB-pathway and the pathway regulating PGC1α. Moreover, miRNAs and piRNAs/piRNA-like molecules are largely differentially regulated in cells and post-mortem tissue samples between control- and PD-patients. The most striking differences can be found in piRNAs/piRNA-like molecules, with SINE- and LINE-derived piRNAs highly downregulated in a disease specific manner. We conclude that neuronal cells derived from sporadic PD-patients help to elucidate novel disease mechanisms and provide relevant insight into the epigenetic landscape of sporadic Parkinson's disease as particularly regulated by small RNAs.
In order to understand whether early epigenetic mechanisms instruct the long-term behavior of neural stem cells (NSCs) and their progeny, we examined Uhrf1 (ubiquitin-like PHD ring finger-1; also ...known as Np95), as it is highly expressed in NSCs of the developing brain and rapidly down-regulated upon differentiation. Conditional deletion of Uhrf1 in the developing cerebral cortex resulted in rather normal proliferation and neurogenesis but severe postnatal neurodegeneration. During development, deletion of Uhrf1 lead to global DNA hypomethylation with a strong activation of the intracisternal A particle (IAP) family of endogenous retroviral elements, accompanied by an increase in 5-hydroxymethylcytosine. Down-regulation of Tet enzymes rescued the IAP activation in Uhrf1 conditional knockout (cKO) cells, suggesting an antagonistic interplay between Uhrf1 and Tet on IAP regulation. As IAP up-regulation persists into postnatal stages in the Uhrf1 cKO mice, our data show the lack of means to repress IAPs in differentiating neurons that normally never express Uhrf1 The high load of viral proteins and other transcriptional deregulation ultimately led to postnatal neurodegeneration. Taken together, these data show that early developmental NSC factors can have long-term effects in neuronal differentiation and survival. Moreover, they highlight how specific the consequences of widespread changes in DNA methylation are for certain classes of retroviral elements.
A
bstract
We study the impact of different theoretical descriptions of top quark pair production on top quark mass measurements in the di-lepton channel. To this aim, the full NLO corrections to
pp
→
...W
+
W
−
b
b
¯
→
e
+
ν
e
μ
−
ν
¯
μ
b
b
¯
production are compared to calculations in the narrow width approximation, where the production of a top quark pair is calculated at NLO and combined with three different descriptions of the top quark decay: leading order, next-to-leading order and via a parton shower. The different theory predictions then enter the calibration of template fit functions, which are used for a fit to pseudo-data. The offsets in the top quark mass resulting from the fits based on the various theoretical descriptions are determined.
Cancer driving mutations are difficult to identify especially in the non-coding part of the genome. Here, we present sigDriver, an algorithm dedicated to call driver mutations. Using 3813 ...whole-genome sequenced tumors from International Cancer Genome Consortium, The Cancer Genome Atlas Program, and a childhood pan-cancer cohort, we employ mutational signatures based on single-base substitution in the context of tri- and penta-nucleotide motifs for hotspot discovery. Knowledge-based annotations on mutational hotspots reveal enrichment in coding regions and regulatory elements for 6 mutational signatures, including APOBEC and somatic hypermutation signatures. APOBEC activity is associated with 32 hotspots of which 11 are known and 11 are putative regulatory drivers. Somatic single nucleotide variants clusters detected at hypermutation-associated hotspots are distinct from translocation or gene amplifications. Patients carrying APOBEC induced PIK3CA driver mutations show lower occurrence of signature SBS39. In summary, sigDriver uncovers mutational processes associated with known and putative tumor drivers and hotspots particularly in the non-coding regions of the genome.
PDF
