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Related papers: A framework for second-order parton showers

200 papers

We claim that factorization implies that the evolution kernel, defined by the logarithmic derivative of the N-th moment of the structure function d ln F_2^N / d ln Q^2, receives logarithmically enhanced contributions (Sudakov logs) from a…

High Energy Physics - Phenomenology · Physics 2009-11-07 E. Gardi , R. G. Roberts

We evaluate the theoretical uncertainties in next-to-leading order plus parton shower predictions for top quark pair production and decay in hadronic collisions. Our work is carried out using the Herwig 7 event generator and presents an…

High Energy Physics - Phenomenology · Physics 2020-01-08 Kyle Cormier , Simon Plätzer , Christian Reuschle , Peter Richardson , Stephen Webster

By measuring the substructure of a jet, one can assign it a "quark" or "gluon" tag. In the eikonal (double-logarithmic) limit, quark/gluon discrimination is determined solely by the color factor of the initiating parton (C_F versus C_A). In…

We introduce a general framework to construct multi-emission kernels for parton branching algorithms at the amplitude level and across different soft and collinear limits. We highlight the connection of kinematic parameterizations and…

High Energy Physics - Phenomenology · Physics 2021-12-30 Maximilian Löschner , Simon Plätzer , Emma Simpson Dore

We discuss recent work on methods for incorporating nonleading QCD corrections in parton shower algorithms.

High Energy Physics - Phenomenology · Physics 2007-05-23 F. Hautmann

An improved QED Parton Shower algorithm to calculate photonic radiative corrections to QED processes at flavour factories is described. We consider the possibility of performing photon generation in order to take into account also the…

High Energy Physics - Phenomenology · Physics 2009-11-07 Carlo Michel Carloni Calame

We specify recursive equations that could be used to generate a lowest order parton shower for hard scattering in hadron-hadron collisions. The formalism is based on the factorization soft and collinear interactions from relatively harder…

High Energy Physics - Phenomenology · Physics 2009-04-22 Zoltan Nagy , Davison E. Soper

We present a selection of results from our recent study of $pp\to t\bar{t}W^\pm$ production matched to partons showers at NLO QCD at the LHC. Theoretical predictions are obtained at perturbative orders $\mathcal{O}(\alpha_s^3\alpha)$ and…

High Energy Physics - Phenomenology · Physics 2021-10-26 Manfred Kraus

Our aim is to show how the reggeization of the gluon, encoded in the bootstrap property of the BFKL kernel, permits to calculate the interaction kernel in the octet colour channel in the forward and non forward direction, for the quark…

High Energy Physics - Phenomenology · Physics 2016-11-23 G. P. Vacca

The merging of matrix elements and parton showers is an established calculational tool for the description of multi-jet final states at hadron colliders. These methods have recently been promoted to next-to-leading order accuracy in the…

High Energy Physics - Phenomenology · Physics 2013-11-15 Marek Schonherr , Stefan Hoeche , Frank Krauss , Frank Siegert

Sudakov-type distributions are at the heart of generating radiation in parton showers as well as contemporary NLO matching algorithms along the lines of the POWHEG algorithm. In this paper, the C++ library ExSample is introduced, which…

High Energy Physics - Phenomenology · Physics 2015-05-30 Simon Platzer

A method for incorporating information from next-to-leading order QCD matrix elements for hadronic diboson production into showering event generators is presented. In the hard central region (high jet transverse momentum) where perturbative…

High Energy Physics - Phenomenology · Physics 2009-11-07 Matt Dobbs

The structure of the double-pole approximation for the O(alpha) corrections to e^+e^- -> WW -> 4 fermions is described, and some results are presented. Moreover, results on full tree-level predictions for $e^+e^- -> WW -> 4 fermions + gamma…

High Energy Physics - Phenomenology · Physics 2007-05-23 A. Denner , S. Dittmaier , M. Roth , D. Wackeroth

We report on the implementation of an interface between the SANC generator framework for Drell-Yan hard processes, which includes next-to-leading order electroweak (NLO EW) corrections, and the Herwig++ and Pythia8 QCD parton shower Monte…

High Energy Physics - Phenomenology · Physics 2015-05-20 P. Richardson , R. R. Sadykov , A. A. Sapronov , M. H. Seymour , P. Z. Skands

We formulate PanScales parton showers for hadron collisions so as to achieve next-to-leading logarithmic (NLL) accuracy across a broad set of observables. We do so specifically for colour singlet production. Relative to the existing…

High Energy Physics - Phenomenology · Physics 2022-11-23 Melissa van Beekveld , Silvia Ferrario Ravasio , Gavin P. Salam , Alba Soto-Ontoso , Gregory Soyez , Rob Verheyen

We present a new approach to combine multiple NLO parton-level calculations matched to parton showers into a single inclusive event sample. The method provides a description of hard multi-jet configurations at next-to leading order in the…

High Energy Physics - Phenomenology · Physics 2013-02-14 Thomas Gehrmann , Stefan Hoeche , Frank Krauss , Marek Schonherr , Frank Siegert

The connection between analytic and Monte Carlo calculations of soft gluon emission is reanalyzed in light of recent, theoretical developments in resummation. An alternative Monte Carlo algorithm is suggested which incorporates (1)…

High Energy Physics - Phenomenology · Physics 2007-05-23 S. Mrenna

Higher order calculations are necessary to predict and describe measurements in high energy collider physics. In recent years multiple approaches to combine multiple next-to-leading (NLO) order corrections with parton showers had been…

High Energy Physics - Phenomenology · Physics 2016-07-08 Johannes Bellm

We study QCD radiation in decay processes involving heavy particles. As input, the first-order gluon emission rate is calculated in a number of reactions, and comparisons of the energy flow patterns show a non-negligible process dependence.…

High Energy Physics - Phenomenology · Physics 2011-01-13 E. Norrbin , T. Sjöstrand

We discuss the necessary steps for implementing an angularly ordered (AO) electroweak (EW) parton shower in Herwig 7 multi-purpose event generator. This includes calculating the helicity-dependent quasi-collinear EW branching functions that…

High Energy Physics - Phenomenology · Physics 2022-04-26 M. R. Masouminia , P. Richardson