LHC EFT WG note: SMEFT predictions, event reweighting, and simulation

Journal Article · 28 November 2024 · SciPost Phys.Comm.Rep.

DOI: https://doi.org/10.21468/SciPostPhysCommRep.4 · OSTI ID:2396953

Belvedere, Alberto ^[1]; Bhattacharya, Saptaparna ^[2]; Boldrini, Giacomo ^[3]; Chatterjee, Suman ^[4]; Calandri, Alessandro ^[5]; Sánchez Cruz, Sergio ^[6]; Dickinson, Jennet ^[7]; Glessgen, Franz Jacob ^[5]; Goldouzian, Reza ^[8]; Grohsjean, Alexander ^[1]; Jeppe, Laurids ^[1]; Knight, Charlotte  ^[9]; Mattelaer, Olivier ^[3]; Mohrman, Kelci  ^[10]; Nelson, Hannah ^[8]; Perovic, Vasilije ^[5]; Presilla, Matteo ^[11]; Schoefbeck, Robert ^[4]; Smith, Nick  ^[7]

---

1. DESY
2. Wayne State U.
3. Ecole Polytechnique; Louvain U.
4. Vienna, OAW
5. ETH, Zurich (main)
6. CERN
7. Fermilab
8. Notre Dame U.
9. Imperial Coll., London
10. Florida U.
11. KIT, Karlsruhe, ETP

This note provides a comprehensive overview of tools for predicting observables in the Standard Model effective field theory (SMEFT) at both tree level and one loop using event generators. We evaluate three primary methodologies–event reweighting, separate simulation of squared matrix elements, and full SMEFT process simulation–focusing on their statistical performance, computational efficiency, and potential biases. Each approach is assessed in terms of its accuracy, highlighting trade-offs between precision and resource demands. Practical insights into their applicability for high-energy physics analyses are offered, with particular attention to processes where SMEFT effects are significant. Additionally, we discuss the role of helicity in reweighting strategies and its impact on the quality of predictions. By comparing the methods across various LHC processes, this note provides guidance for selecting the most effective strategy for various SMEFT studies, ensuring robust predictions while optimizing computational resources.

• Research Organization: CERN; DESY; ETH, Zurich (main); Ecole Polytechnique; Fermi National Accelerator Laboratory (FNAL), Batavia, IL (United States); Florida U.; Imperial Coll., London; KIT, Karlsruhe, ETP; Louvain U.; Notre Dame U.; Vienna, OAW; Wayne State U.
• Sponsoring Organization: US Department of Energy
• Grant/Contract Number: 89243024CSC000002; AC02-07CH11359
• OSTI ID: 2396953
• Report Number(s): CERN-LHCEFTWG-2024-001; CERN-LPCC-2024-001; FERMILAB-PUB-24-0350-PPD; oai:inspirehep.net:2801212; arXiv:2406.14620
• Journal Information: SciPost Phys.Comm.Rep., Journal Name: SciPost Phys.Comm.Rep.
• Country of Publication: United States
• Language: English