Non-singlet coefficient functions for charged-current deep-inelastic scattering to the third order in QCD

We have calculated the coefficient functions for the structure functions F_2, F_L and F_3 in nu-nubar charged-current deep-inelastic scattering (DIS) at the third order in the strong coupling alpha_s, thus completing the description of unpolarized inclusive W^(+-) exchange DIS to this order of massless perturbative QCD. In this brief note, our new results are presented in terms of compact approximate expressions that are sufficiently accurate for phenomenological analyses. For the benefit of such analyses we also collect, in a unified notation, the corresponding lower-order contributions and the flavour non-singlet coefficient functions for nu+nubar charged-current DIS. The behaviour of all six third-order coefficient functions at small Bjorken-x is briefly discussed

Four-loop QCD propagators and vertices with one vanishing external momentum

We have computed the self-energies and a set of three-particle vertex functions for massless QCD at the four-loop level in the MSbar renormalization scheme. The vertex functions are evaluated at points where one of the momenta vanishes. Analytical results are obtained for a generic gauge group and with the full gauge dependence, which was made possible by extensive use of the Forcer program for massless four-loop propagator integrals. The bare results in dimensional regularization are provided in terms of master integrals and rational coefficients; the latter are exact in any space-time dimension. Our results can be used for further precision investigations of the perturbative behaviour of the theory in schemes other than MSbar. As an example, we derive the five-loop beta function in a relatively common alternative, the minimal momentum subtraction (MiniMOM) scheme.Comment: 50 pages, 4 figures, 15 ancillary files available with the source; v2: minor changes, version accepted by JHE

A single-site feasibility randomised controlled trial comparing ‘<em>my hypo compass</em>’ short pyscho-educational intervention with standard care alone in individuals with type 1 diabetes and impaired awareness of hypoglycaemia

\ua9 2024 The Author(s). Diabetic Medicine published by John Wiley &amp; Sons Ltd on behalf of Diabetes UK.Aims: The HypoCOMPaSS multi-centre trial achieved improvement in hypoglycaemia awareness and 20-fold reduction in severe hypoglycaemia (SH) in a cohort with long-standing type 1 diabetes (T1D). All participants received ‘my hypo compass’ (MHC) brief structured psycho-educational intervention in addition to optimisation of insulin delivery/glucose monitoring. In this 24-week, prospective, single-centre feasibility RCT, we piloted MHC as a sole intervention in comparison to standard clinical care alone (CON). Methods: Participants with T1D and impaired hypoglycaemia awareness (IAH) (Clarke score ≥4) were recruited. MHC comprised a group/individual 1–2 h face-to-face session followed by a telephone call and second face-to-face session at 4 weeks. Outcome measures at 24 weeks were compared with baseline. Results: Fifty-two individuals provided consent for screening with 39 fulfilling eligibility criteria. Fifteen withdrew before any study intervention. Twenty-four adults with (mean \ub1 SD) T1D duration 41.0 \ub1 15.1 years commenced/completed the study (100% visit attendance); 12 randomised to MHC and 12 to CON. All had IAH at baseline and at 24 weeks. Annualised SH rate following MHC was 3.8 \ub1 19.0 (24 weeks) versus 12.6 \ub1 3.5 (Baseline) and in CON group 2.0 \ub1 19.0 (24 weeks) versus 4.6 \ub1 11.5 (Baseline). ‘Immediate Action’ for and ‘Worry’ about hyperglycaemia measured by the Hyperglycaemia Avoidance Scale appeared lower following MHC. Participants attended all study visits and reflected positively on the MHC intervention. Conclusions: Feasibility of MHC implementation without additional intervention has been demonstrated. MHC education was associated with positive changes in attitudes and behaviours with the potential to reduce SH risk. MHC provides a validated, simple, well-received programme to fulfil the educational component within RCTs targeting problematic hypoglycaemia and as part of holistic clinical care

On Higgs decays to hadrons and the R-ratio at (NLO)-L-4

We present the first determination of Higgs-boson decay to hadrons at the next-to-next-to-next-to-next-to-leading order of perturbative QCD in the limit of a heavy top quark and massless light flavours. This result has been obtained by computing the absorptive parts of the relevant five-loop self-energy for a general gauge group and combining the outcome with the corresponding coefficient function already known to this order in QCD. Our new result reduces the uncertainty due to the truncation of the perturbation series to a fraction of the uncertainty due to the present error of the strong coupling constant. We have also performed the corresponding but technically simpler computations for direct Higgs decay to bottom quarks and for the electromagnetic R-ratio in e^+ e^- -> hadrons, thus verifying important fifth-order results obtained so far only by one group.Comment: 26 pages, LaTeX, 2 axodraw2 and 4 eps figures. FORM files of the main results available with the source. v2: version accepted by JHEP: introduction and summary slightly extended, minor other text changes, a few additional reference

Optimization of sediment rating curve coefficients using evolutionary algorithms and unsupervised artificial neural network

Sediment rating curve (SRC) is a conventional and a common regression model in estimating suspended sediment load (SSL) of flow discharge. However, in most cases the data log-transformation in SRC models causing a bias which underestimates SSL prediction. In this study, using the daily stream flow and suspended sediment load data from Shalman hydrometric station on Shalmanroud River, Guilan Province, Iran, SRC equation was derived, and then, using evolutionary algorithms (genetic algorithm and particle swarm optimization algorithm) it was calibrated again. Worth mentioning, before model calibration, to increase the generalization power of the models, using self-organizing map (an unsupervised artificial neural network for data clustering), the data were clustered and then by data sampling, they were classified into two homogeneous groups (calibration and test data set). The results showed that evolutionary algorithms are appropriate methods for optimizing coefficients of SRC model and their results are much more favorable than those of the conventional SRC models or SRC models corrected by correction factors. So that, the sediment rating curve models calibrated with evolutionary algorithms, by reducing the RMSE of the test data set of 5754.02 ton day-1 (in the initial SRC model) to 1681.21 ton day-1 (in the calibrated models by evolutionary algorithms) increased the accuracy of suspended sediment load estimation at a rate of 4072.81 ton day-1 . In total, using evolutionary algorithms in calibrating SRC models prevents data log-transformation and use of correction factors along with increasing in the accuracy of molding results

Four-loop non-singlet splitting functions in the planar limit and beyond

We present the next-to-next-to-next-to-leading order (N3LO) contributions to the non-singlet splitting functions for both parton distribution and fragmentation functions in perturbative QCD. The exact expressions are derived for the terms contributing in the limit of a large number of colours. For the remaining contributions, approximations are provided that are sufficient for all collider-physics applications. From their threshold limits we derive analytical and high-accuracy numerical results, respectively, for all contributions to the four-loop cusp anomalous dimension for quarks, including the terms proportional to quartic Casimir operators. We briefly illustrate the numerical size of the four-loop corrections, and the remarkable renormalization-scale stability of the N3LO results, for the evolution of the non-singlet parton distribution and the fragmentation functions. Our results appear to provide a first point of contact of four-loop QCD calculations and the so-called wrapping corrections to anomalous dimensions in N=4 super Yang-Mills theory

Identification and characterization of thousands of bacteriophage satellites across bacteria

Bacteriophage-bacteria interactions are affected by phage satellites, elements that exploit phages for transfer between bacteria. Satellites can encode defense systems, antibiotic resistance genes, and virulence factors, but their number and diversity are unknown. We developed SatelliteFinder to identify satellites in bacterial genomes, detecting the four best described families: P4-like, phage inducible chromosomal islands (PICI), capsid-forming PICI, and PICI-like elements (PLE). We vastly expanded the number of described elements to ∼5000, finding bacterial genomes with up to three different families of satellites. Most satellites were found in Proteobacteria and Firmicutes, but some are in novel taxa such as Actinobacteria. We characterized the gene repertoires of satellites, which are variable in size and composition, and their genomic organization, which is very conserved. Phylogenies of core genes in PICI and cfPICI indicate independent evolution of their hijacking modules. There are few other homologous core genes between other families of satellites, and even fewer homologous to phages. Hence, phage satellites are ancient, diverse, and probably evolved multiple times independently. Given the many bacteria infected by phages that still lack known satellites, and the recent proposals for novel families, we speculate that we are at the beginning of the discovery of massive numbers and types of satellites

On quartic colour factors in splitting functions and the gluon cusp anomalous dimension

We have computed the contributions of the quartic Casimir invariants to the four-loop anomalous dimensions of twist-2 spin-N operators at N =< 16. The results provide new information on the structure of the next-to-next-to-next-to-leading order (N^3LO) splitting functions P_{ik}^(3)(x) for the evolution of parton distributions, and facilitate approximate expressions which include the quartic-Casimir contributions to the (light-like) gluon cusp anomalous dimension. These quantities turn out to be closely related, by a generalization of the lower-order `Casimir scaling', to the corresponding quark results. Using these findings, we present an approximate result for the four-loop gluon cusp anomalous dimension in QCD which is sufficient for phenomenological applications.Comment: 12 pages, LaTe

FORM, diagrams and topologies

© Copyright owned by the author(s) under the terms of the Creative Commons. We discuss a number of FORM features that are essential in the automatic processing of very large numbers of diagrams as used in the Forcer program for 4-loop massless propagator diagrams. Most of these features are new

Mutant mitochondrial elongation factor G1 and combined oxidative phosphorylation deficiency

Although most components of the mitochondrial translation apparatus are encoded by nuclear genes, all known molecular defects associated with impaired mitochondrial translation are due to mutations in mitochondrial DNA. We investigated two siblings with a severe defect in mitochondrial translation, reduced levels of oxidative phosphorylation complexes containing mitochondrial DNA (mtDNA)–encoded subunits, and progressive hepatoencephalopathy. We mapped the defective gene to a region on chromosome 3q containing elongation factor G1 (EFG1), which encodes a mitochondrial translation factor. Sequencing of EFG1 revealed a mutation affecting a conserved residue of the guanosine triphosphate (GTP)–binding domain. These results define a new class of gene defects underlying disorders of oxidative phosphorylation