[Paper Review] The Discovery of the Higgs Boson with the CMS Detector and its Implications for Supersymmetry and Cosmology

W. De Boer|arXiv (Cornell University)|Sep 3, 2013

Particle physics theoretical and experimental studies42 references3 citations

TL;DR

This paper presents the CMS experiment's discovery of the Higgs boson at 125.7 GeV, confirming its couplings to vector bosons and fermions as predicted by the Standard Model. The observed mass lies within the supersymmetry-predicted range below 130 GeV, providing indirect evidence for supersymmetry despite no direct detection of superpartners, and highlights the Higgs boson's limited role in cosmological mass and dark energy, which remains unexplained by the Higgs mechanism.

ABSTRACT

The discovery of the long awaited Higgs boson is described using data from the CMS detector at the LHC. In the SM the masses of fermions and the heavy gauge bosons are generated by the interactions with the Higgs field, so all couplings are related to the observed masses. Indeed, all observed couplings are consistent with the predictions from the Higgs mechanism, both to vector bosons and fermions implying that masses are indeed consistent of being generated by the interactions with the Higgs field. However, on a cosmological scale the mass of the universe seems not to be related to the Higgs field: the baryonic mass originates from the binding energy of the quarks inside the nuclei and dark matter is not even predicted in the SM, so the origin of its mass is unknown. The dominant energy component in the universe, the dark energy, yields an accelerated expansion of the universe, so its repulsive gravity most likely originates from a kind of vacuum energy. The Higgs field would be the prime candidate for this, if the energy density would not be many orders of magnitude too high, as will be calculated. The Higgs mass is found to be 125.7$\pm$0.3(stat.)$\pm$0.3(syst.) GeV, which is below 130 GeV, i.e. in the range predicted by supersymmetry. This may be the strongest hint for supersymmetry in spite of the fact that the predicted supersymmetric particles have not been discovered so far.

Motivation & Objective

• To present the experimental discovery of the Higgs boson using data from the CMS detector at the LHC.
• To test whether the observed Higgs boson's couplings to gauge bosons and fermions are consistent with the Standard Model Higgs mechanism.
• To evaluate the cosmological implications of the Higgs field, particularly its role in dark energy and the universe's mass-energy budget.
• To assess the Higgs boson mass as indirect evidence for supersymmetry, despite the absence of direct superpartner detection.
• To explore the potential for additional Higgs bosons in models like the NMSSM, especially via double Higgs production and invisible decays.

Proposed method

• Analysis of proton-proton collision data collected by the CMS detector at the LHC, focusing on Higgs boson decay channels such as γγ, WW*, ZZ*, and bb̄.
• Comparison of observed branching ratios and production rates with Standard Model predictions to test consistency of the Higgs mechanism.
• Use of statistical significance tests to confirm the discovery of a new particle at 125.7 GeV with uncertainties of ±0.3(stat.) ±0.3(syst.) GeV.
• Evaluation of the Higgs boson mass in the context of supersymmetric models, particularly the MSSM and NMSSM, to assess its compatibility with theoretical predictions.
• Investigation of cosmological constraints, including vacuum energy density from the Higgs field and its discrepancy with observed dark energy.
• Simulation and analysis of potential signatures for extended Higgs sectors, such as double Higgs production and invisible decays in the NMSSM.

Experimental results

Research questions

• RQ1 Is the observed particle consistent with the Standard Model Higgs boson in terms of its couplings to vector bosons and fermions?
• RQ2 Does the measured Higgs boson mass of 125.7 GeV provide evidence for supersymmetry, despite the absence of direct superpartner signals?
• RQ3 To what extent can the Higgs field account for the universe's dark energy, given the hierarchy problem between predicted and observed vacuum energy?
• RQ4 What are the implications of the Higgs boson for cosmological phase transitions, including electroweak symmetry breaking and inflation?
• RQ5 Can the discovery of a 125.7 GeV Higgs boson serve as a unique signature for extended Higgs sectors such as the NMSSM, particularly through double Higgs production or invisible decays?

Key findings

• The Higgs boson mass was measured at 125.7 ± 0.3(stat.) ± 0.3(syst.) GeV, consistent with the Standard Model prediction and within the supersymmetry-predicted range below 130 GeV.
• All observed couplings of the Higgs boson to vector bosons and fermions are consistent with the Standard Model, confirming that masses are generated via the Higgs mechanism.
• The Higgs field is not the dominant source of mass in the universe; baryonic mass arises primarily from quark binding energy, and dark matter remains unexplained by the Standard Model.
• The predicted vacuum energy from the Higgs field is many orders of magnitude larger than the observed dark energy, indicating a major theoretical inconsistency.
• The Higgs boson mass provides the strongest indirect hint for supersymmetry to date, despite no direct detection of superpartners.
• In models like the NMSSM, the heavier Higgs boson can decay into two lighter Higgses with a branching ratio up to 41%, offering a unique signature for double Higgs production not present in the MSSM.