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Professor Peter Richardson's Outputs (97)

Herwig 7.3 release note (2024)
Journal Article
Bewick, G., Ferrario Ravasio, S., Gieseke, S., Kiebacher, S., Masouminia, M. R., Papaefstathiou, A., Plätzer, S., Richardson, P., Samitz, D., Seymour, M. H., Siódmok, A., & Whitehead, J. (2024). Herwig 7.3 release note. The European Physical Journal C, 84(10), Article 1053. https://doi.org/10.1140/epjc/s10052-024-13211-9

A new release of the Monte Carlo event generator Herwig (version 7.3) has been launched. This iteration encompasses several enhancements over its predecessor, version 7.2. Noteworthy upgrades include: the implementation of a process-independent elect... Read More about Herwig 7.3 release note.

Hadronization and decay of excited heavy hadrons in Herwig 7 (2024)
Journal Article
Masouminia, M. R., & Richardson, P. (2024). Hadronization and decay of excited heavy hadrons in Herwig 7. Journal of High Energy Physics, 2024(7), Article 278. https://doi.org/10.1007/jhep07%282024%29278

We revisit the hadronization and decay of excited heavy mesons and heavy baryons in Herwig 7 general-purpose event-generator, following four distinct steps: (i) Passing through the polarisation of heavy hadrons at the end of parton shower through the... Read More about Hadronization and decay of excited heavy hadrons in Herwig 7.

UFO 2.0: the ‘Universal Feynman Output’ format (2023)
Journal Article
Darmé, L., Degrande, C., Duhr, C., Fuks, B., Goodsell, M., Heinrich, G., …Zaro, M. (2023). UFO 2.0: the ‘Universal Feynman Output’ format. The European Physical Journal C, 83(7), Article 631. https://doi.org/10.1140/epjc/s10052-023-11780-9

We present an update of the Universal FeynRules Output model format, commonly known as the UFO format, that is used by several automated matrix-element generators and high-energy physics software. We detail different features that have been proposed... Read More about UFO 2.0: the ‘Universal Feynman Output’ format.

Implementation of angularly ordered electroweak parton shower in Herwig 7 (2022)
Journal Article
Masouminia, M., & Richardson, P. (2022). Implementation of angularly ordered electroweak parton shower in Herwig 7. Journal of High Energy Physics, 2022(4), Article 112. https://doi.org/10.1007/jhep04%282022%29112

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 correspon... Read More about Implementation of angularly ordered electroweak parton shower in Herwig 7.

Initial state radiation in the Herwig 7 angular-ordered parton shower (2022)
Journal Article
Bewick, G., Ravasio, S. F., Richardson, P., & Seymour, M. H. (2022). Initial state radiation in the Herwig 7 angular-ordered parton shower. Journal of High Energy Physics, 2022(1), Article 26. https://doi.org/10.1007/jhep01%282022%29026

We study the simulation of initial-state radiation in angular-ordered parton showers in order to investigate how different interpretations of the ordering variable affect the logarithmic accuracy of such showers. This also enables us to implement a r... Read More about Initial state radiation in the Herwig 7 angular-ordered parton shower.

Hadronic footprint of GeV-mass dark matter (2020)
Journal Article
Plehn, T., Reimitz, P., & Richardson, P. (2020). Hadronic footprint of GeV-mass dark matter. SciPost Physics, 8(6), Article 092. https://doi.org/10.21468/scipostphys.8.6.092

GeV-scale dark matter is an increasingly attractive target for direct detection, indirect detection, and collider searches. Its annihilation into hadronic final states produces a challenging zoo of light hadronic resonances. We update Herwig7 to stud... Read More about Hadronic footprint of GeV-mass dark matter.

Herwig 7.2 release note (2020)
Journal Article
Bellm, J., Bewick, G., Ferrario Ravasio, S., Gieseke, S., Grellscheid, D., Kirchgaeßer, P., Loshaj, F., Masouminia, M. R., Nail, G., Papaefstathiou, A., Plätzer, S., Podskubka, R., Rauch, M., Reuschle, C., Richardson, P., Schichtel, P., Seymour, M. H., Siódmok, A., & Webster, S. (2020). Herwig 7.2 release note. The European Physical Journal C, 80(5), Article 452. https://doi.org/10.1140/epjc/s10052-020-8011-x

A new release of the Monte Carlo event generator Herwig (version 7.2) is now available. This version introduces a number of improvements over the major version 7.0, notably: multi-jet merging with the dipole shower at LO and NLO QCD; spin correlation... Read More about Herwig 7.2 release note.

Logarithmic accuracy of angular-ordered parton showers (2020)
Journal Article
Bewick, G., Ravasio, S. F., Richardson, P., & Seymour, M. H. (2020). Logarithmic accuracy of angular-ordered parton showers. Journal of High Energy Physics, 2020(4), Article 19. https://doi.org/10.1007/jhep04%282020%29019

We study the logarithmic accuracy of angular-ordered parton showers by considering the singular limits of multiple emission matrix elements. This allows us to consider different choices for the evolution variable and propose a new choice which has bo... Read More about Logarithmic accuracy of angular-ordered parton showers.

Robust Independent Validation of Experiment and Theory: Rivet version 3 (2020)
Journal Article
Bierlich, C., Buckley, A., Butterworth, J., Christensen, C. H., Corpe, L., Grellscheid, D., Grosse-Oetringhaus, J. F., Gutschow, C., Karczmarczyk, P., Klein, J., Lönnblad, L., Pollard, C. S., Richardson, P., Schulz, H., & Siegert, F. (2020). Robust Independent Validation of Experiment and Theory: Rivet version 3. SciPost Physics, 8(2), Article 026. https://doi.org/10.21468/scipostphys.8.2.026

First released in 2010, the RIVET library forms an important repository for analysis code, facilitating comparisons between measurements of the final state in particle collisions and theoretical calculations of those final states. We give an overview... Read More about Robust Independent Validation of Experiment and Theory: Rivet version 3.

Spin correlations in parton shower simulations (2019)
Journal Article
Richardson, P., & Webster, S. (2019). Spin correlations in parton shower simulations. The European Physical Journal C, 80(2), Article 83. https://doi.org/10.1140/epjc/s10052-019-7429-5

Spin correlations are an important, but often neglected, effect in modern Monte Carlo event generators. We show that they can be fully incorporated in HERWIG7 using the algorithm originally proposed by Collins and Knowles in all stages of the event g... Read More about Spin correlations in parton shower simulations.

Improving the simulation of quark and gluon jets with Herwig 7 (2017)
Journal Article
Reichelt, D., Richardson, P., & Siodmok, A. (2017). Improving the simulation of quark and gluon jets with Herwig 7. The European Physical Journal C, 77(12), Article 876. https://doi.org/10.1140/epjc/s10052-017-5374-8

The properties of quark and gluon jets, and the differences between them, are increasingly important at the LHC. However, Monte Carlo event generators are normally tuned to data from e+e−e+e− collisions which are primarily sensitive to quark-initiate... Read More about Improving the simulation of quark and gluon jets with Herwig 7.

Colour Reconnections in Quark and Gluon Jets in Herwig 7 (2017)
Journal Article
Reichelt, D., Richardson, P., & Siódmok, A. (2017). Colour Reconnections in Quark and Gluon Jets in Herwig 7. Acta Physica Polonica B, 48(6), 1167-1173. https://doi.org/10.5506/aphyspolb.48.1167

Major event generators deviate significantly in their description of quark and gluon initiated jets. The modelling of these is particularly sensitive to the colour reconnection model used in the cluster hadronization model in the event generator Herw... Read More about Colour Reconnections in Quark and Gluon Jets in Herwig 7.

Reweighting parton showers (2016)
Journal Article
Bellm, J., Plätzer, S., Richardson, P., Siódmok, A., & Webster, S. (2016). Reweighting parton showers. Physical Review D, 94(3), Article 034028. https://doi.org/10.1103/physrevd.94.034028

We report on the possibility of reweighting parton-shower Monte Carlo predictions for scale variations in the parton-shower algorithm. The method is based on a generalization of the Sudakov veto algorithm. We demonstrate the feasibility of this appro... Read More about Reweighting parton showers.

Herwig 7.0/Herwig++ 3.0 release note (2016)
Journal Article
Bellm, J., Gieseke, S., Grellscheid, D., Plätzer, S., Rauch, M., Reuschle, C., …Rauch, D. (2016). Herwig 7.0/Herwig++ 3.0 release note. The European Physical Journal C, 76(4), Article 196. https://doi.org/10.1140/epjc/s10052-016-4018-8

A major new release of the Monte Carlo event generator Herwig++ (version 3.0) is now available. This release marks the end of distinguishing Herwig++ and HERWIG development and therefore constitutes the first major release of version 7 of the Herwig... Read More about Herwig 7.0/Herwig++ 3.0 release note.

Studying the sensitivity of monotop probes to compressed supersymmetric scenarios at the LHC (2015)
Journal Article
Fuks, B., Richardson, P., & Wilcock, A. (2015). Studying the sensitivity of monotop probes to compressed supersymmetric scenarios at the LHC. The European Physical Journal C, 75(7), Article 308. https://doi.org/10.1140/epjc/s10052-015-3530-6

We investigate the sensitivity of the Large Hadron Collider to supersymmetric setups using monotop probes in which the signal is a single top quark produced in association with missing transverse energy. Our prospective study relies on Monte Carlo si... Read More about Studying the sensitivity of monotop probes to compressed supersymmetric scenarios at the LHC.

Monte Carlo Simulation of Hard Radiation in Decays in Beyond the Standard Model Physics in Herwig++ (2014)
Journal Article
Richardson, P., & Wilcock, A. (2014). Monte Carlo Simulation of Hard Radiation in Decays in Beyond the Standard Model Physics in Herwig++. The European Physical Journal C, 74(1), Article 2713. https://doi.org/10.1140/epjc/s10052-014-2713-x

We use the POWHEG formalism in the Herwig++ event generator to match QCD real-emission matrix elements with the parton shower for a range of decays relevant to Beyond the Standard Model physics searches. Applying this correction affects the shapes of... Read More about Monte Carlo Simulation of Hard Radiation in Decays in Beyond the Standard Model Physics in Herwig++.