[Paper Review] Extra Dimensions and the Universal Suppression of Higgs Boson Observables at High Energy Colliders

James D. Wells|arXiv (Cornell University)|May 29, 2002

Particle physics theoretical and experimental studies4 citations

TL;DR

This paper investigates how low-scale extra dimensions can universally suppress Higgs boson production rates across high-energy colliders due to the Higgs boson's narrow width and fermion mass hierarchies. It shows that while the Tevatron and LHC struggle to detect small universal suppression, a high-energy e⁺e⁻ collider can effectively probe such effects, offering a unique sensitivity to new physics beyond the Standard Model.

ABSTRACT

Precision electroweak data suggests the existence of a light Standard Model Higgs boson. Its width is very narrow by an accident of the fermion mass hierarchies, and so slight perturbations to the theory induce dramatic changes in the phenomenology of direct Higgs boson production. Several theory ideas motivated by low-scale extra dimensions lead to a universal rate suppression of Higgs boson observables. The Tevatron and LHC will have difficulty accruing compelling evidence for small universal suppression of rate observables, and even more difficulty discerning the underlying cause. A high energy e + e − collider would have relatively little trouble. The narrow Higgs boson The most effective searches to date for the Higgs boson in the Standard Model (SM) come from e + e − → hSMZ experiments at LEPII. They have put a 95 % C.L. numerical limit on the Higgs boson mass of mhSM> 114.1 GeV [1]. Meanwhile, precision electroweak analyses based mostly on LEP, SLD and Tevatron data have put indirect limits on the SM Higgs boson mass [2]: log

Motivation & Objective

• To investigate the phenomenological consequences of low-scale extra dimensions on Higgs boson observables.
• To analyze how the narrow width of the Higgs boson amplifies sensitivity to small perturbations in the theory.
• To assess the detectability of universal rate suppression in Higgs production at the Tevatron, LHC, and future e⁺e⁻ colliders.
• To determine the comparative advantages of e⁺e⁻ colliders in probing universal suppression effects that are difficult to observe at hadron colliders.

Proposed method

• Using precision electroweak data to infer constraints on the Standard Model Higgs boson mass.
• Modeling the impact of low-scale extra dimensions on Higgs couplings and decay widths.
• Applying the framework of universal rate suppression due to modifications in the Higgs sector from extra dimensions.
• Evaluating the sensitivity of different collider environments—specifically e⁺e⁻, hadron colliders—to small universal suppression of Higgs production rates.
• Leveraging the narrow width of the Higgs boson to amplify the phenomenological effects of small theoretical perturbations.
• Comparing expected signal rates and statistical significance across colliders to assess detectability of universal suppression.

Experimental results

Research questions

• RQ1 How do low-scale extra dimensions lead to a universal suppression of Higgs boson production rates in high-energy collisions?
• RQ2 Why is the narrow width of the Higgs boson critical in amplifying the phenomenological impact of small theoretical perturbations?
• RQ3 What is the detectability of universal rate suppression at the Tevatron and LHC, given their hadronic environments?
• RQ4 In what way does a high-energy e⁺e⁻ collider offer superior sensitivity to universal suppression compared to hadron colliders?
• RQ5 How do precision electroweak data and direct Higgs searches at LEPII constrain the parameter space for universal suppression?

Key findings

• Low-scale extra dimensions lead to a universal suppression of Higgs boson production rates due to modifications in the Higgs sector.
• The narrow width of the Higgs boson makes its phenomenology highly sensitive to small perturbations, amplifying observable effects.
• The Tevatron and LHC face significant challenges in accumulating compelling evidence for small universal suppression of Higgs rates.
• Even more difficulty arises in distinguishing the underlying cause of such suppression at hadron colliders.
• A high-energy e⁺e⁻ collider is shown to have significantly better sensitivity to detect universal suppression effects.
• Direct searches at LEPII have established a 95% confidence level lower limit on the Higgs boson mass of 114.1 GeV.