- The paper presents a novel quantification of NLO electroweak corrections, showing a +5% shift in the Higgs production cross section for a 120 GeV mass scenario.
- It compares two factorization schemes that either multiply or add corrections, offering refined estimates of theoretical uncertainties.
- For Higgs masses above 160 GeV, the study reveals a transition to negative corrections near the top-antitop threshold, highlighting mass-dependent electroweak effects.
Analysis of NLO Electroweak Corrections in Higgs Production via Gluon Fusion
The paper examines the next-to-leading order (NLO) electroweak corrections to the production of the Standard Model Higgs boson through gluon fusion at hadron colliders, a principal channel for Higgs production. Researchers have robustly explored radiative corrections, particularly at the LHC, where next-to-leading order (NLO) quantum chromodynamics (QCD) corrections substantially enhance the cross section compared to leading-order results. This paper focuses on elucidating the less understood electroweak effects, which are equally crucial given their contribution to the theoretical uncertainty associated with Higgs boson production cross sections.
Key Findings
- Electroweak Corrections Quantified: The research presents quantitative analysis for NLO electroweak corrections, employing a complex-mass scheme to circumvent artificially large threshold effects. The reported results demonstrate a +5% shift in the cross-section at NLO electroweak levels when compared to the next-to-next-to-leading order (NNLO) QCD cross-section for a Higgs boson mass of 120 GeV at both LHC and Tevatron energies.
- Factorization and Uncertainty: Two different factorization schemes for electroweak effects were adopted, leading to computed estimates of total theoretical uncertainty. In the Complete Factorization (CF) approach, the electroweak corrections scale multiplicatively with QCD corrections, whereas, in the Partial Factorization (PF) scheme, electroweak corrections are only added to the leading order, not affecting higher-order QCD contributions. This consideration is essential for estimating the theoretical uncertainties more accurately.
- Higher Higgs Mass Impacts: For a Higgs mass range exceeding 160 GeV, the paper finds that corrections transition to negative values, reaching a local minimum around the top-antitop threshold. This transition highlights the influence of quark masses and electroweak interactions at higher energy scales.
- Complex-Mass Scheme Implementation: The avoidance of unphysical singularities around WW, ZZ, and t-tbar thresholds, verified through the complex-mass scheme, represents a significant computational strategy in obtaining reliable predictions for the Higgs production cross-section.
Practical and Theoretical Implications
The research provides a refined approximation of NLO electroweak corrections, which is pivotal for accurate theoretical predictions. The inclusion of these corrections is vital for aligning theoretical predictions with experimental data and for the accurate extraction of Higgs boson properties. Moreover, accounting for electroweak corrections reduces uncertainties leading to more decisive interpretation, especially in scenarios where soft-gluon resummation effects compete with electroweak influences.
Future Directions
Future work should extend towards integrating mixed QCD and electroweak corrections beyond NLO, given the computational advance to accommodate such hybrid diagrams. Additionally, further refinement in the modeling of parton distribution functions will reduce uncertainties. Continued overlap with NNLL soft-gluon resummation studies is anticipated to offer new insights into the most accurate modeling of gluon fusion processes. As the LHC continues to unlock new energy regimes, such comprehensive theoretical frameworks will remain crucial in the hunt for new physics.
In conclusion, this paper elucidates the nuanced role of electroweak corrections in Higgs boson production, aligning theoretical predictions more closely with empirical data, and setting the foundation for future high precision studies in particle physics.
