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13 papers found.
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MINLO t-channel single-top plus jet

Abstract We present a next-to-leading order accurate simulation of t-channel single-top plus jet production matched to parton showers via the Powheg method. The calculation underlying the simulation is enhanced with a process-specific implementation of the multi-scale improved NLO (Minlo) method, such that it gives physical predictions all through phase space, including regions...

Logarithmic accuracy of parton showers: a fixed-order study

Abstract We formulate some first fundamental elements of an approach for assessing the logarithmic accuracy of parton-shower algorithms based on two broad criteria: their ability to reproduce the singularity structure of multi-parton matrix elements, and their ability to reproduce logarithmic resummation results. We illustrate our approach by considering properties of two...

Extending the Minlo method

We consider improving Powheg+Minlo simulations, so as to also render them NLO accurate in the description of observables receiving contributions from events with lower parton multiplicity than present in their underlying NLO calculation. On a conceptual level we follow the strategy of the so-called Minlo ′ programs. Whereas the existing Minlo ′ framework requires explicit...

Finite quark-mass effects in the NNLOPS POWHEG+MiNLO Higgs generator

We include finite top- and bottom-mass effects in the next-to-next-to-leading order parton shower (NNLOPS) event generator for inclusive Higgs boson production in gluon fusion based upon the POWHEG+MiNLO approach. Since fixed-order results for quark-mass effects only reach NLO accuracy, we add them to the NNLOPS generator at that accuracy. We explore uncertainties related to the...

NNLOPS simulation of Higgs boson production

We detail a simulation of Higgs boson production via gluon fusion, accurate at next-to-next-to-leading order in the strong coupling, including matching to a parton shower, yielding a fully exclusive, hadron-level description of the final-state. The approach relies on the Powheg method for merging the NLO Higgs plus jet cross-section with the parton shower, and on the Minlo method...

Merging H/W/Z + 0 and 1 jet at NLO with no merging scale: a path to parton shower + NNLO matching

We consider the POWHEG generator for a H/W/Z boson plus one jet, augmented with the recently proposed MiNLO method for the choice of scales and the inclusion of Sudakov form factors. Within this framework, the generator covers all the transverse- momentum region of the H/W/Z boson, i.e. no generation cuts are needed to obtain a finite result. By construction, the generator...

MINLO: multi-scale improved NLO

In the present work we consider the assignment of the factorization and renormalization scales in hadron collider processes with associated jet production, at next-to-leading order (NLO) in perturbation theory. We propose a simple, definite prescription to this end, including Sudakov form factors to consistently account for the distinct kinematic scales occuring in such...

Practical improvements and merging of Powheg simulations for vector boson production

In this article we generalise Powheg next-to-leading order parton shower (Nlops) simulations of vector boson production and vector boson production in association with a single jet, to give matrix element corrected Menlops simulations. In so doing we extend and provide, for the first time, an exact and faithful implementation of the Menlops formalism in hadronic collisions. We...

Jet pair production in POWHEG

We present an implementation of the next-to-leading order dijet production process in hadronic collisions in the framework of POWHEG, which is a method to implement NLO calculations within a shower Monte Carlo context. In constructing the simulation, we have made use of the POWHEG BOX toolkit, which makes light of many of the most technical steps. The majority of this article is...

Herwig++ physics and manual

In this paper we describe \(\mathsf{Herwig++}\) version 2.2, a general-purpose Monte Carlo event generator for the simulation of hard lepton-lepton and hadron-hadron collisions. A number of important hard scattering processes are available, together with an interface via the Les Houches Accord to specialized matrix element generators for additional processes. The simulation of...

A microscale protein NMR sample screening pipeline

As part of efforts to develop improved methods for NMR protein sample preparation and structure determination, the Northeast Structural Genomics Consortium (NESG) has implemented an NMR screening pipeline for protein target selection, construct optimization, and buffer optimization, incorporating efficient microscale NMR screening of proteins using a micro-cryoprobe. The process...

The oral examination in anaesthetic resident evaluation

Oral examinations have a traditional place in training and evaluation of professionals. Despite a lack of evidence identifying their value in assessment of candidates seeking anaesthetic specialty certification, oral examinations continue to be widely used. Although there is a considerable body of literature concerning oral examinations, there is no description of how this...

1468 PHYSIOLOGICAL CHANGES INDUCED BY ENDOTRACHEAL INSTILLATION AND SUCTIONING IN CRITICALLY ILL PRETERM INFANTS WITH AND WITHOUT SEDATION

. Abraham Ninan, LATION AND SUCTIONING IN CRITICALLY ILL PRETERM Maureen O'Donnell, Keith Hamilton, Koravangattu Sankaran, University of Saskatchewan College of Medicine, University Hospital, Department of