180 research outputs found
NLO QCD corrections to the production of Higgs plus two jets at the LHC
We present the calculation of the NLO QCD corrections to the associated
production of a Higgs boson and two jets, in the infinite top-mass limit. We
discuss the technical details of the computation and we show the numerical
impact of the radiative corrections on several observables at the LHC. The
results are obtained by using a fully automated framework for fixed order NLO
QCD calculations based on the interplay of the packages GoSam and Sherpa. The
evaluation of the virtual corrections constitutes an application of the
d-dimensional integrand-level reduction to theories with higher dimensional
operators. We also present first results for the one-loop matrix elements of
the partonic processes with a quark-pair in the final state, which enter the
hadronic production of a Higgs boson together with three jets in the infinite
top-mass approximation.Comment: 9 pages, 7 figures, references added, published in Phys.Lett.
Automated one-loop calculations with GoSam 2.0
We present the version 2.0 of the program GoSam, which is a public program
package to compute one-loop corrections to multi-particle processes. The
extended version of the "Binoth-Les-Houches-Accord" interface to Monte Carlo
programs is also implemented. This allows a large flexibility regarding the
combination of the code with various Monte Carlo programs to produce fully
differential NLO results, including the possibility of parton showering and
hadronisation. We describe the new features of the code and illustrate the wide
range of applicability for multi-particle processes at NLO, both within and
beyond the Standard Model.Comment: 9 pages, talk given at the conference "Loops and Legs in Quantum
Field Theory", Weimar, Germany, April 201
GoSam-2.0: a tool for automated one-loop calculations within the Standard Model and beyond
We present the version 2.0 of the program package GoSam for the automated
calculation of one-loop amplitudes. GoSam is devised to compute one-loop QCD
and/or electroweak corrections to multi-particle processes within and beyond
the Standard Model. The new code contains improvements in the generation and in
the reduction of the amplitudes, performs better in computing time and
numerical accuracy, and has an extended range of applicability. The extended
version of the "Binoth-Les-Houches-Accord" interface to Monte Carlo programs is
also implemented. We give a detailed description of installation and usage of
the code, and illustrate the new features in dedicated examples.Comment: replaced by published version and reference adde
DiagnĂłstico da cobertura vegetal no meio urbano em Campinas.
O objetivo deste estudo foi diagnosticar a cobertura vegetal da årea urbana de Campinas por meio da anålise da cobertura do solo urbano. Para isso, foram analisadas imagens de Campinas adquiridas pelo satélite WorldView 2 no ano de 2012
To , or not to : Recent developments and comparisons of regularization schemes
We give an introduction to several regularization schemes that deal with
ultraviolet and infrared singularities appearing in higher-order computations
in quantum field theories. Comparing the computation of simple quantities in
the various schemes, we point out similarities and differences between them.Comment: 61 pages, 12 figures; version sent to EPJC, references update
MoleculARweb: A Web Site for Chemistry and Structural Biology Education through Interactive Augmented Reality out of the Box in Commodity Devices
Augmented/virtual realities (ARs/VRs) promise to revolutionize STEM education. However, most easy-to-use tools are limited to static visualizations, which limits the approachable content, whereas more interactive and dynamic alternatives require costly hardware, preventing large-scale use and evaluation of pedagogical effects. Here, we introduce https://MoleculARweb.epfl.ch, a free, open-source web site with interactive AR webpage-based apps that work out-of-the-box in laptops, tablets, and smartphones, where students and teachers can naturally handle virtual objects to explore molecular structure, reactivity, dynamics, and interactions, covering topics from inorganic, organic, and biological chemistry. With these web apps, teachers and science communicators can develop interactive material for their lessons and hands-on activities for their students and target public, in person or online, as we exemplify. Thousands of accesses to moleculARweb attest to the ease of use; teacher feedback attests to the utility in online teaching and homework during a pandemic; and in-class plus online surveys show that users find AR engaging and useful for teaching and learning chemistry. These observations support the potential of AR in future education and show the large impact that modern web technologies have in democratizing access to digital learning tools, providing the possibility to mass-test the pedagogical effect of these technologies in STEM education.Fil: RodrĂguez, Fabio CortĂ©s. Ăcole Polytechnique FĂ©dĂ©rale de Lausanne; Suiza. Swiss Institute of Bioinformatics; SuizaFil: Frattini, Gianfranco. Universidad Nacional de Rosario. Facultad de Ciencias BioquĂmicas y FarmacĂ©uticas; ArgentinaFil: Krapp, Lucien F.. Ecole Polytechnique Federale de Lausanne; Francia. Swiss Institute of Bioinformatics; SuizaFil: Martinez Hung, Hassan. Universidad de Oriente; VenezuelaFil: Moreno, Diego Martin. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Rosario. Instituto de QuĂmica Rosario. Universidad Nacional de Rosario. Facultad de Ciencias BioquĂmicas y FarmacĂ©uticas. Instituto de QuĂmica Rosario; ArgentinaFil: RoldĂĄn, Mariana. Provincia de CĂłrdoba. Instituto Colbert; ArgentinaFil: SalomĂłn, Jorge Eduardo. Provincia de Buenos Aires. Escuela de EducaciĂłn TĂ©cnica Nro. 4; ArgentinaFil: Stemkoski, Lee. Adelphi University; Estados UnidosFil: Traeger, Sylvain. Ăcole Polytechnique FĂ©dĂ©rale de Lausanne; Suiza. Swiss Institute of Bioinformatics; SuizaFil: Dal Peraro, Matteo. Ăcole Polytechnique FĂ©dĂ©rale de Lausanne; Suiza. Swiss Institute of Bioinformatics; SuizaFil: Abriata, Luciano Andres. Ăcole Polytechnique FĂ©dĂ©rale de Lausanne; Suiza. Swiss Institute of Bioinformatics; Suiz
Integrand reduction of one-loop scattering amplitudes through Laurent series expansion
We present a semi-analytic method for the integrand reduction of one-loop
amplitudes, based on the systematic application of the Laurent expansions to
the integrand-decomposition. In the asymptotic limit, the coefficients of the
master integrals are the solutions of a diagonal system of equations, properly
corrected by counterterms whose parametric form is konwn a priori. The Laurent
expansion of the integrand is implemented through polynomial division. The
extension of the integrand-reduction to the case of numerators with rank larger
than the number of propagators is discussed as well.Comment: v2: Published version: references and two appendices added. v3:
Eq.(6.11) corrected, Appendix B updated accordingl
S-acylation controls SARS-CoV-2 membrane lipid organization and enhances infectivity
SARS-CoV-2 virions are surrounded by a lipid bilayer that contains membrane proteins such as spike, responsible for target-cell binding and virus fusion. We found that during SARS-CoV-2 infection, spike becomes lipid modified, through the sequential action of the S-acyltransferases ZDHHC20 and 9. Particularly striking is the rapid acylation of spike on 10 cytosolic cysteines within the ER and Golgi. Using a combination of computational, lipidomics, and biochemical approaches, we show that this massive lipidation controls spike biogenesis and degradation, and drives the formation of localized ordered cholesterol and sphingolipid-rich lipid nanodomains in the early Golgi, where viral budding occurs. Finally, S-acylation of spike allows the formation of viruses with enhanced fusion capacity. Our study points toward S-acylating enzymes an
Blood pressure and metabolic effects of acetyl-L-carnitine in type 2 diabetes: DIABASI randomized controlled trial
Context: Acetyl-L-carnitine (ALC), a mitochondrial carrier involved in lipid oxidation and glucose metabolism, decreased systolic blood pressure (SBP), and ameliorated insulin sensitivity in hypertensive nondiabetic subjects at high cardiovascular risk. Objective: To assess the effects of ALC on SBP and glycemic and lipid control in patients with hypertension, type 2 diabetes mellitus (T2D), and dyslipidemia on background statin therapy. Design: After 4-week run-in period and stratification according to previous statin therapy, patients were randomized to 6-month, double-blind treatment with ALC or placebo added-on simvastatin. Setting: Five diabetology units and one clinical research center in Italy. Patients: Two hundred twenty-nine patients with hypertension and dyslipidemic T2D > 40 years with stable background antihypertensive, hypoglycemic, and statin therapy and serum creatinine < 1.5 mg/ dL. Interventions: Oral ALC 1000 mg or placebo twice daily on top of stable simvastatin therapy. Outcome and Measures: Primary outcome was SBP. Secondary outcomes included lipid and glycemic profiles. Total-body glucose disposal rate and glomerular filtration rate were measured in subgroups by hyperinsulinemic-euglycemic clamp and iohexol plasma clearance, respectively. Results: SBP did not significantly change after 6-month treatment with ALC compared with placebo (-2.09mmHg vs-3.57mmHg, P = 0.9539). Serum cholesterol, triglycerides, and lipoprotein(a), as well as blood glucose, glycated hemoglobin, fasting insulin levels, homeostatic model assessment of insulin resistance index, glucose disposal rate, and glomerular filtration rate did not significantly differ between treatments. Adverse events were comparable between groups. Conclusions: Six-month oral ALC supplementation did not affect blood pressure, lipid and glycemic control, insulin sensitivity and kidney function in hypertensive normoalbuminuric and microalbuminuric T2D patients on background statin therapy
To d , or not to d : recent developments and comparisons of regularization schemes
We give an introduction to several regularization schemes that deal with ultraviolet and infrared singularities appearing in higher-order computations in quantum field theories. Comparing the computation of simple quantities in the various schemes, we point out similarities and differences between them
- âŠ