Unparticles-Higgs Interplay

TL;DR

This paper explores how scalar unparticles interacting with the Higgs can induce electroweak symmetry breaking at tree level, alter Higgs properties, and affect the unparticle sector, revealing new dynamics beyond the Standard Model.

Contribution

It demonstrates that unparticles coupled to the Higgs can trigger electroweak symmetry breaking without a Higgs mass term and analyzes their impact on Higgs mass and width.

Findings

Unparticles can induce electroweak symmetry breaking at tree level.

Unparticles can shift the Higgs mass away from the Standard Model prediction.

Unparticles can significantly increase the Higgs width above the mass gap.

Abstract

We show that scalar unparticles coupled to the Standard Model Higgs at the renormalizable level can have a dramatic impact in the breaking of the electroweak symmetry already at tree level. In particular one can get the proper electroweak scale without the need of a Higgs mass term in the Lagrangian. By studying the mixed unparticle-Higgs propagator and spectral function we also show how unparticles can shift the Higgs mass away from its Standard Model value, \lambda v^2, and influence other Higgs boson properties. Conversely, we study in some detail how electroweak symmetry breaking affects the unparticle sector by breaking its conformal symmetry and generating a mass gap. We also show that, for Higgs masses above that gap, unparticles can increase quite significantly the Higgs width.