Probing the Standard Model with Higgs signal rates from the Tevatron, the LHC and a future ILC (1403.1582v2)

Abstract: We explore the room for possible deviations from the Standard Model (SM) Higgs boson coupling structure in a systematic study of Higgs coupling scale factor benchmark scenarios using the latest signal rate measurements from the Tevatron and LHC experiments. We employ chi-squared fits performed with HiggsSignals, which takes into account detailed information on signal efficiencies and major correlations of theoretical and experimental uncertainties. All considered scenarios allow for additional non-standard Higgs boson decay modes, and various assumptions for constraining the total decay width are discussed. No significant deviations from the SM Higgs boson coupling structure are found in any of the investigated benchmark scenarios. We derive upper limits on an additional (undetectable) Higgs decay mode under the assumption that the Higgs couplings to weak gauge bosons do not exceed the SM prediction. We furthermore discuss the capabilities of future facilities for probing deviations from the SM Higgs couplings, comparing the high luminosity upgrade of the LHC with a future International Linear Collider (ILC), where for the latter various energy and luminosity scenarios are considered. At the ILC model-independent measurements of the coupling structure can be performed, and we provide estimates of the precision that can be achieved.

• The paper applies comprehensive χ² fits of Higgs coupling scale factors from Tevatron and LHC data, finding no significant deviations from the Standard Model.
• It constrains potential non-standard decay modes by comparing benchmark scenarios and evaluates systematic uncertainties in current measurements.
• The analysis emphasizes that future colliders like the ILC could achieve unprecedented precision in probing subtle deviations in Higgs physics.

Exploring the Coupling Structure of the Higgs Boson and Implications for Future Collider Experiments

The research paper explores the deviations from the Standard Model (SM) in the Higgs boson coupling structure using the most recent Higgs signal rate measurements from the Tevatron and LHC experiments. The authors perform a comprehensive statistical analysis of the Higgs coupling scale factors (κ) across various benchmark scenarios. These scenarios allow consideration of additional non-standard Higgs boson decay modes, with assumptions for constraining the total decay width discussed in detail. A key finding is that no substantial deviations from the SM Higgs boson coupling structure are discerned in any examined benchmark setting.

The analysis involves χ² fits incorporating detailed signal efficiencies and considerations of major theoretical and experimental uncertainties. In particular, the paper emphasizes comparing future facility capabilities in probing deviations from SM Higgs couplings, highlighting the anticipated performance of upcoming colliders like the International Linear Collider (ILC) against the HL-LHC.

Key Findings and Implications

1. Current Higgs Coupling Measurements:
   • The analysis finds no significant deviations from SM predictions for the Higgs boson couplings with current data from LHC and Tevatron experiments.
   • Additionally, the paper provides upper constraints on additional undetectable decay modes of the Higgs boson, assuming the Higgs couplings do not exceed SM predictions.
2. Future Prospects:
   • The future high-luminosity upgrade of the LHC (3000 fb⁻¹) and potential future electron-positron colliders like the ILC offer powerful avenues for further testing the Higgs coupling structure.
   • Model-independent measurements at the ILC may achieve precise coupling measurements, revealing any deviations more finely than the LHC might, suggesting that the ILC would enable an unprecedented level of precision in Higgs physics.
3. Benchmark Models and Deviations:
   • Various benchmark scenarios representing systematic deviations from the SM were explored. These benchmarks assessed modifications in universal coupling modifications, discriminations between vector boson and fermion couplings, and loop-induced processes.
   • Despite the current data largely supporting the SM, future experimental capabilities will provide a higher sensitivity towards detecting or constraining minimal deviations.
4. Correlated and Uncorrelated Systematic Uncertainties:
   • The paper evaluates different systematic and parametric uncertainties affecting the cross section and decay width predictions, improving the precision of coupling determinations.
5. Model-Dependent vs. Model-Independent Analyses:
   • While the paper emphasizes model-independent determinations of Higgs properties at future colliders, it underscores that current constraints rely on model-dependent assumptions due to limitations in directly measuring the Higgs total decay width.

Speculations on Future Developments in AI and Physics

The research has far-reaching implications for the ongoing and future investigations into elementary particles and the forces underlying their interactions. As high precision measurements become increasingly feasible with advancements like the ILC, the degree to which we can test the SM will significantly enhance. Beyond addressing questions on the Higgs mechanism, such advancements may steer new physics explorations beyond the SM perspective in scenarios such as supersymmetry or extra-dimensional models.

Furthermore, leveraging AI techniques for data analysis can greatly expedite processing and pattern recognition within enormous datasets offered by collider experiments. With AI, novel statistical techniques or machine learning models could be developed to further optimize the analysis of emerging experimental findings, providing real-time or near-real-time discrimination of subtle effects pivotal for discoveries beyond the SM.

The authors' work provides crucial insights and a foundation for approaching the next frontier in particle physics research, underscoring that comprehensive precision studies of Higgs properties can pave pathways toward an enriched understanding of fundamental physics.