- The paper establishes a maximum lightest Higgs boson mass of approximately 132 GeV (or 128 GeV with thermal leptogenesis), linking it to the scale of SUSY breaking.
- It demonstrates that supergravity-mediated SUSY breaking yields tree-level scalar masses and one-loop gaugino masses, streamlining the MSSM framework.
- The research outlines collider and dark matter implications, suggesting LHC detection prospects for winos below 2.7 TeV and providing targets for future experiments.
The research presented by Ibe and Yanagida delves deeply into the predictions and constraints of the lightest Higgs boson mass within the framework of the Pure Gravity Mediation (PGM) model. This model is situated within the larger scope of the Minimal Supersymmetric Standard Model (MSSM) and emphasizes the mediation of supersymmetry (SUSY) breaking via gravitational interactions without introducing additional fields beyond the MSSM.
Key Observations and Analysis
- SUSY Breaking and Mass Generation:
- In PGM, SUSY breaking occurs through supergravity effects. Scalar superpartners receive soft masses at tree level, while gauge fermions acquire mass at the one-loop level.
- The gaugino masses, notably, emerge without additional mediating fields, an attractive feature simplifying field content in PGM.
- The Higgs Sector and Electroweak Symmetry Breaking:
- The Higgs sector in PGM becomes an area of interest because one expects the μ- and B-terms, characterizing the Higgs fields' masses, to align with the scale of the gravitino mass.
- As a result, phenomena such as successful electroweak symmetry breaking necessitate that one Higgs boson (identified as a mix of up-type and down-type Higgses) remains light despite the large initial mass scale predictions.
- Higgs Boson Mass Predictions:
- The lightest Higgs boson mass is constrained to a maximum of approximately 132 GeV without additional conditions. When considering thermal leptogenesis for baryon asymmetry, this constraint tightens to 128 GeV.
- The mass is primarily influenced by the scale of SUSY breaking, tanβ, and the anomaly-mediated contributions to gaugino masses.
- Dark Matter Considerations:
- The neutral wino emerges as a compelling dark matter candidate within PGM, determined by its thermal relic density.
- The research outlines the delicate balance between wino mass, dark matter density, and the universe's reheating temperature post-inflation. This interdependence further influences the potential detection of dark matter particles in cosmic observations.
- Implications for Collider Experiments:
- Prospective experimental verifications at the Large Hadron Collider (LHC) provide a critical test for the model's predictions. The anticipation of detecting gauginos, specifically winos with less than 2.7 TeV mass, could affirm the mass limits derived for the Higgs boson.
- The exploration of errors in top mass and strong coupling constants, along with theoretical uncertainties, highlights the model’s robustness yet sensitive dependence on precise parameters.
Theoretical and Practical Implications
The Pure Gravity Mediation model posited by Ibe and Yanagida offers insightful constraints on Higgs boson mass predictions linked intricately with gravitational SUSY breaking. The model's absence of additional mediating fields simplifies theoretical constructs, providing clarity in predictive modeling. Practically, the implications for LHC experiments pave the way for validation through observable parameters, such as scalar boson mass, gaugino mass spectrum, and potential dark matter candidates. As we push towards more precise measurements and refined collider data, this research provides a critical theoretical framework that bridges high-energy physics with cosmological observations. Additionally, future advances in AI may enhance data analysis accuracy, facilitating further refinement of such models.