Search results

Filter

Filetype

Your search for "*" yielded 533629 hits

Joan Didion banar vägen för Trump

Den amerikanska författaren Joan Didions Politiska fiktioner avslöjar det symbiotiska förhållandet mellan politiken och politiska journalister i USA. Samtidigt banar henne synsätt vägen för missnöjespolitiker som Trump.

Automation of NLO computations using the FKS subtraction method

In this talk the FKS subtraction method for next-to-leading order (in QCD) computations is reviewed and its automation in the computer code MadFKS is presented. As a proof of concept, some results in the form of plots for distributions at next-to-leading order in e+e− → 2, 3 and 4 jets are shown by interfacing this code to BlackHat and Rocket.

Automation of one-loop QCD computations

We present the complete automation of the computation of one-loop QCD corrections, including UV renormalization, to an arbitrary scattering process in the Standard Model. This is achieved by embedding the OPP integrand reduction technique, as implemented in CutTools, into the MadGraph framework. By interfacing the tool so constructed, which we dub MadLoop, with MadFKS, the fully automatic computat

Scalar and pseudoscalar Higgs production in association with a top-antitop pair

We present the calculation of scalar and pseudoscalar Higgs production in association with a top-antitop pair to the next-to-leading order (NLO) accuracy in QCD, interfaced with parton showers according to the MC@NLO formalism. We apply our results to the cases of light and very light Higgs boson production at the LHC, giving results for total rates as well as for sample differential distributions

W and Z/γ* boson production in association with a bottom-antibottom pair

We present a study of lνbb and l++l-bb production at hadron colliders. Our results, accurate to the next-to-leading order in QCD, are based on automatic matrix-element calculations performed byMadLoop andMadFKS, and are given at both the parton level, and after the matching with the Herwig event generator, achieved with aMC@NLO. We retain the complete dependence on the bottom-quark mass, and inclu

Four-lepton production at hadron colliders : AMC@NLO predictions with theoretical uncertainties

We use aMC@NLO to study the production of four charged leptons at the LHC, performing parton showers with both HERWIG and Pythia6. Our underlying matrix element calculation features the full next-to-leading order O(α S) result and the O(α S 2) contribution of the gg channel, and it includes all off-shell, spin-correlation, virtualphoton-exchange, and interference effects. We present several key di

AMC@NLO predictions for W jj production at the Tevatron

We use aMC@NLO to predict the ℓ? + 2-jet cross section at the NLO accuracy in QCD matched to parton shower simulations. We find that the perturbative expansion is well behaved for all the observables we study, and in particular for those relevant to the experimental analyses. We therefore conclude that NLO corrections to this process cannot be responsible for the excess of events in the dijet inva

NLO Higgs boson production plus one and two jets using the POWHEG BOX, MadGraph4 and MCFM

We present a next-to-leading order calculation of Higgs boson production plus one and two jets via gluon fusion interfaced to shower Monte Carlo programs, implemented according to the POWHEG method. For this implementation we have used a new interface of the POWHEG BOX with MadGraph4, that generates the codes for generic Born and real processes automatically. The virtual corrections have been take

Single-top t-channel hadroproduction in the four-flavour scheme with POWHEG and aMC@NLO

We present results for the QCD next-to-leading order (NLO) calculation of single-top t-channel production in the 4-flavour scheme, interfaced to Parton Shower (PS) Monte Carlo programs according to the POWHEG and MC@NLO methods. Comparisons between the two methods, as well as with the corresponding process in the 5-flavour scheme are presented. For the first time results for typical kinematic dist

W boson plus heavy flavour (theory)

In this talk we give an overview of the theory status for the predictions of W boson production in association with bottom quarks with relevance to top quark phenomenology.

Merging meets matching in MC@NLO

The next-to-leading order accuracy for MC@NLO results exclusive in J light jets is achieved if the computation is based on matrix elements that feature J and J + 1 QCD partons. The simultaneous prediction of observables which are exclusive in different light-jet multiplicities cannot simply be obtained by summing the above results over the relevant range in J; rather, a suitable merging procedure

Diphoton production in the ADD model to NLO + parton shower accuracy at the LHC

In this paper, we present the next-to-leading order predictions for diphoton production in the ADD model, matched to the HERWIG parton shower using the MC@NLO formalism. A selection of the results is presented for d = 2-6 extra dimensions, using generic cuts as well as analysis cuts mimicking the search strategies as pursued by the ATLAS and CMS experiments.

Automatic spin-entangled decays of heavy resonances in Monte Carlo simulations

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

"Inget för de lärde?" : Diskussionerna om lokaliseringen av de tekniska elemenatarskolorna i Sverge i mitten av 1800-talet

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

Single-top t-channel production with off-shell and non-resonant effects

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