Higgs-graviscalar mixing in type I string theory

TL;DR

This paper explores the mixing between Higgs and graviscalar particles in string theory models with TeV-scale strings, revealing potential invisible Higgs decay channels relevant for low-scale quantum gravity phenomenology.

Contribution

It provides a string-theoretic framework to compute Higgs-graviscalar mixing, connecting string excitations to observable Higgs properties in low-scale models.

Findings

Higgs can mix with bulk graviscalars in D-brane models.

Mixing leads to an invisible decay width of the Higgs.

Results support phenomenological implications for TeV-scale quantum gravity.

Abstract

We investigate the possibility of mixing between open and closed string excitations in D-brane models with the fundamental string scale at the TeV. The open string modes describe the Standard Model Higgs, while closed strings describe graviscalars living in the bulk. This provides a string setup for computing the Higgs-graviscalar mixing, that leads to a phenomenologically interesting invisible width of the Higgs in low scale quantum gravity models, as suggested previously by Giudice, Rattazzi and Wells.