We present a general method that allows one to decay narrow resonances in Les Houches Monte Carlo events in an efficient and accurate way. The procedure preserves both spin correlation and finite width effects to a very good accuracy, and is therefore particularly suited for the decay of resonances in production events generated at next-to-leading-order accuracy. The method is implemented as a gen

Avsaknaden av en teknisk utbildning på mellannivå framstod i mitten av 1800-talet som såväl ett industrialiserings- som ett moderniseringshinder. Som svar på dessa problem etablerades tekniska elementarskolor under 1850-talet i Malmö, Borås, Örebro och Norrköping. Föreliggande artikel behandlar de viktigaste faktorerna bakom lokaliseringen av dessa skolor och svarar på frågorna varför de förlades

This Letter details and discusses the next-to-leading order QCD corrections to t-channel electro-weak W+bj production, where finite top-width effects are consistently taken into account. The computation is done within the aMCatNLO framework and includes both resonant and non-resonant contributions as well as interferences between the two. Results are presented for the LHC and compared to those of

We introduce a framework, based on an effective field theory approach, that allows one to perform characterisation studies of the boson recently discovered at the LHC, for all the relevant channels and in a consistent, systematic and accurate way. The production and decay of such a boson with various spin and parity assignments can be simulated by means of multi-parton, tree-level matrix elements

In this paper, we present the next-to-leading order QCD corrections for di-lepton, di-electroweak boson (ZZ, W+W-) production in both the SM and the ADD model, matched to the HERWIG parton shower using the aMC@NLO framework. A selection of results at the 8 TeV LHC, which exhibit deviations from the SM as a result of the large extra-dimension scenario, are presented.

Many highly developed Monte Carlo tools for the evaluation of cross sections based on tree matrix elements exist and are used by experimental collaborations in high energy physics. As the evaluation of one-loop matrix elements has recently been undergoing enormous progress, the combination of one-loop matrix elements with existing Monte Carlo tools is on the horizon. This would lead to phenomenolo

We present the complete next-to-leading-order (NLO) contributions to the pp→e+νeμ-ν̄μbb̄+X process in the four-flavor scheme, i.e., with massive b quarks, and its contribution to the H→WW(*) →llνν measurement in the 1-jet bin at the LHC. This background process includes top pair, single top, and non-top-quark resonant contributions. The uncertainty at NLO from the renormalization and factorization

We present predictions for the SM-Higgs-pair production channels of relevance at the LHC: gluon-gluon fusion, VBF, and top-pair, W, Z and single-top associated production. All these results are at the NLO accuracy in QCD, and matched to parton showers by means of the MC@NLO method; hence, they are fully differential. With the exception of the gluon-gluon fusion process, for which a special treatme

We compare the impact of top-quark spin polarization effects in Higgs boson production in association with top-quark pairs and in corresponding backgrounds at the LHC. Because of the spin-zero nature of the Higgs boson, one expects, in the chiral limit for the top quarks, a substantial complementarity in tt̄ spin correlations for a Higgs decaying into fermions/gauge-bosons and tt̄ spin correlation

We discuss the theoretical bases that underpin the automation of the computations of tree-level and next-to-leading order cross sections, of their matching to parton shower simulations, and of the merging of matched samples that differ by light-parton multiplicities. We present a computer program, MadGraph5 aMC@NLO, capable of handling all these computations - parton-level fixed order, shower-mat

We present the interface between MadGraph5-aMC@NLO, a self-contained program that calculates cross sections up to next-to-leading order accuracy in an automated manner, and APPLgrid, a code that parametrises such cross sections in the form of look-up tables which can be used for the fast computations needed in the context of PDF fits. The main characteristic of this interface, which we dub aMCfast

W bosons produced at high transverse momentum in hadron collisions can have polarization along the direction perpendicular to the production plane, which is odd under naïve T reversal where both the three-momenta and angular momenta are reversed. Perturbative QCD predicts nonzero polarization at the one-loop level, which can be measured as parity-odd components in the angular distribution of charg

Abstract: We study the production of a Higgs boson in association with bottom quarks in hadronic collisions, and present phenomenological predictions relevant to the 13 TeV LHC. Our results are accurate to the next-to-leading order in QCD, and matched to parton showers through the MC@NLO method; thus, they are fully differential and based on unweighted events, which we shower by using both Herwig+

In electroweak-boson production processes with a jet veto, higher-order corrections are enhanced by logarithms of the veto scale over the invariant mass of the boson system. In this paper, we resum these Sudakov logarithms at next-to-next-to-leading logarithmic accuracy and match our predictions to next-to-leading-order (NLO) fixed-order results. We perform the calculation in an automated way, for

Background: Due to lack of knowledge about seasonal influenza vaccine effectiveness (SIVE) against laboratory-confirmed influenza in patients aged ≥65 years a study to measure SIVE in patients admitted to hospital due to severe acute respiratory infection (SARI) in Lithuania during the 2015-2018 was conducted.Materials/methods: A test-negative case-control study was performed between 2015-2016 and

The associated production of a Higgs boson and a top-quark pair, tt¯H, in proton-proton collisions is addressed in this paper for a center of mass energy of 13 TeV at the LHC. Dileptonic final states of tt¯H events with two oppositely charged leptons and four jets from the decays t→bW+→b+ν, t¯→b¯W-→b¯-ν¯ and h→bb¯, are used. Signal events, generated with MadGraph5-aMC@NLO, are fully reconstructed

We present an interface between the multipurpose Monte Carlo tool MadGraph5_aMC@NLO and the automated amplitude generator GoSam. As a first application of this novel framework, we compute the NLO corrections to (Formula presented.) (Formula presented.) and (Formula presented.) (Formula presented.) matched to a parton shower. In the phenomenological analyses of these processes, we focus our attenti