Report
The Physics of Herwig 7
| Title: | The Physics of Herwig 7 |
|---|---|
| Authors: | Bellm, J., Bewick, G., Ravasio, S. Ferrario, Gieseke, S., Grellscheid, D., Kiebacher, S., Kirchgaeßer, P., Loshaj, F., Masouminia, M. R., Nail, G., Papaefstathiou, A., Plätzer, S., Rauch, M., Reimitz, P., Reuschle, C., Richardson, P., Samitz, D., Sarmah, P., Schichtel, P., Seymour, M. H., Siódmok, A., Stafford, D., Strange, C. B., Sule, S., Webster, S., Whitehead, J. |
| Publication Year: | 2025 |
| Collection: | High Energy Physics - Phenomenology |
| Subject Terms: | High Energy Physics - Phenomenology |
| Description: | We present the physics foundations and recent developments of Herwig 7, the modern successor of the original HERWIG and Herwig++ series. Herwig 7 provides a flexible and systematically improvable framework for the simulation of high-energy lepton and hadron collisions, with particular emphasis on QCD and EW effects. Hard scattering processes are generated within the automated Matchbox framework, which integrates external amplitude providers, supports tree-level, next-to-leading-order (NLO) and loop-induced matrix elements, and implements subtraction schemes, multi-channel phase-space sampling, dynamic scale choices and both POWHEG- and MC@NLO-type matching algorithms. Consistent multijet merging at LO and NLO is provided, enabling precise predictions across a wide range of SM processes. Parton radiation is simulated using two complementary showers: an angular-ordered shower incorporating QCD coherence and the heavy-quark dead-cone effect, and a dipole shower optimised for NLO matching and multijet merging. Higher-order corrections are included through matrix-element corrections and dedicated reweighting techniques, while QED and EW radiation are treated using a YFS formalism and EW showering algorithms. The modelling of non-perturbative physics employs an advanced cluster hadronization framework with improved cluster formation, fission and decay, as well as colour reconnection models, heavy-quark effects and interfaces to alternative hadronization schemes. An extended eikonal multiple-partonic-scattering model, incorporating semi-hard and soft components together with diffractive interactions, enables realistic descriptions of minimum-bias and underlying-event data. Herwig 7 thus represents a versatile event generator, providing a coherent, modular and extensible platform for Standard Model and beyond-the-Standard-Model collider phenomenology at current and future facilities. v2: many minor improvements and corrections, parts of chapter 5 rewritten. 199 pages, 480 references |
| Document Type: | Working Paper |
| DOI: | 10.48550/arXiv.2512.16645 |
| Access URL: | https://arxiv.org/abs/2512.16645 |
| Accession Number: | edsarx.2512.16645 |
| Database: | arXiv |
| DOI: | 10.48550/arXiv.2512.16645 |
|---|