Branes and Orbifolds are Opaque

TL;DR

This paper investigates how localized kinetic terms for gauge fields in extra-dimensional theories are generated by radiative corrections, leading to unpredictable effects on Kaluza-Klein modes and significant phenomenological consequences.

Contribution

It demonstrates that radiative corrections induce divergent localized kinetic terms in extra-dimensional models, affecting gauge field properties and requiring these terms to be treated as independent parameters.

Findings

Radiative corrections produce logarithmically divergent localized kinetic terms.

Such terms significantly alter Kaluza-Klein gauge field masses and couplings.

Implications for phenomenology of extra-dimensional theories are discussed.

Abstract

We examine localized kinetic terms for gauge fields which can propagate into compact extra dimensions. We find that such terms are generated by radiative corrections in both theories with matter fields confined to branes and in theories imposing orbifold boundary conditions on bulk matter. In both cases, the radiative corrections are logarithmically divergent, indicating that from an effective field theory point of view they cannot be predicted in terms of other parameters, and should be treated as independent leading order parameters of the theory. Specializing to the five dimensional case, we show that these terms may result in gross distortions of the Kaluza-Klein gauge field masses, wave functions, and couplings to brane and bulk matter. The resulting phenomenological implications are discussed.