SciPost Submission Page
State-of-the-art cross sections for ttH: NNLO predictions matched with NNLL resummation and EW corrections
by Roger Balsach, Alessandro Broggio, Simone Devoto, Andrea Ferroglia, Rikkert Frederix, Massimiliano Grazzini, Stefan Kallweit, Anna Kulesza, Javier Mazzitelli, Leszek Motyka, Davide Pagani, Benjamin D. Pecjak, Chiara Savoini, Tomasz Stebel, Malgorzata Worek, Marco Zaro
This is not the latest submitted version.
Submission summary
| Authors (as registered SciPost users): | Marco Zaro |
| Submission information | |
|---|---|
| Preprint Link: | https://arxiv.org/abs/2503.15043v1 (pdf) |
| Date submitted: | March 26, 2025, 9:52 a.m. |
| Submitted by: | Marco Zaro |
| Submitted to: | SciPost Physics Community Reports |
| for consideration in Collection: |
| Ontological classification | |
|---|---|
| Academic field: | Physics |
| Specialties: |
|
| Approach: | Theoretical |
Abstract
We present new, state-of-the-art predictions for the associated production of the SM Higgs boson with top quarks, computed in accordance with the recommendations of the LHC Higgs Working Group. The NNLO QCD predictions, derived through suitable approximations of the two-loop virtual contribution, are supplemented with soft-gluon resummation up to NNLL accuracy. Two distinct resummation frameworks are employed - one based on direct QCD and the other on soft-collinear effective theory - and their features are compared in detail. These results are further combined with the complete-NLO corrections, yielding the most precise SM predictions for this process to date. The relevant sources of theoretical uncertainties are thoroughly estimated and discussed.
Current status:
Reports on this Submission
Report #1 by Anonymous (Referee 1) on 2025-7-1 (Invited Report)
- Cite as: Anonymous, Report on arXiv:2503.15043v1, delivered 2025-07-01, doi: 10.21468/SciPost.Report.11491
Strengths
1- It is a thorough combination of the up-to-date predictions for the ttH production process. 2- Uncertainties are carefully explained and taken into account. 3- It provides clear recommendations for experimental analyses.
Weaknesses
1- It is based on a single NNLO calculation which still applies an approximation.
Report
The analysis includes the fixed-order NNLO corrections plus effects from the resummation of logarithmic terms due to soft-gluon emission. Also included are all lower-order effects, which the paper refers to as "complete-NLO" (properly defined in Eq.(2.24)). The fixed-order NNLO corrections are taken from Ref.[44] which still uses an approximation for the actual two-loop contribution, whose uncertainty is estimated and accounted for in the final prediction. Concerning the NNLL resummation, the authors pursue two
conceptually very different approaches, finding only small numerical differences in their numerical effects though.
The central part of the paper is section 3, where numerical recommendations for the inclusive total cross section at the LHC are provided, including a thorough breakdown of all theoretical uncertainties.
The paper is the result of a collaboration of a relatively large group of people (16 authors) which I believe are all part of the LHC Higgs Working Group. Such efforts are very desirable in order to clearly identify the source of any possible differences in different theoretical predictions and provide a clear recommendation to the experimental community which takes any systematic ambiguities into account. I therefore recommend the paper for publication without changes.
Recommendation
Publish (meets expectations and criteria for this Journal)