Higgs Bosons in Warped Space, from the Bulk to the Brane

TL;DR

This paper explores the phenomenology of bulk scalar Higgs bosons in warped extra-dimensional models, analyzing their production at the LHC and flavor-changing effects through analytical and numerical methods, highlighting the importance of higher derivative operators.

Contribution

It introduces a method to reconcile analytical and numerical predictions for bulk Higgs behavior by incorporating higher derivative operators that account for heavy KK mode effects.

Findings

Both approaches agree when the Higgs is far from the brane.

Heavier KK modes do not decouple as the Higgs approaches the TeV brane.

Higher derivative operators effectively encode heavy KK mode effects.

Abstract

In the context of warped extra-dimensional models with all fields propagating in the bulk, we address the phenomenology of a bulk scalar Higgs boson, and calculate its production cross section at the LHC as well as its tree-level effects on mediating flavor changing neutral currents. We perform the calculations based on two different approaches. First, we compute our predictions analytically by considering all the degrees of freedom emerging from the dimensional reduction (the infinite tower of Kaluza Klein modes (KK)). In the second approach, we perform our calculations numerically by considering only the effects caused by the first few KK modes, present in the 4-dimensional effective theory. In the case of a Higgs leaking far from the brane, both approaches give the same predictions as the effects of the heavier KK modes decouple. However, as the Higgs boson is pushed towards the TeV brane, the two approaches seem to be equivalent only when one includes heavier and heavier degrees of freedom (which do not seem to decouple). To reconcile these results it is necessary to introduce a type of higher derivative operator which essentially encodes the effects of integrating out the heavy KK modes and dresses the brane Higgs so that it looks just like a bulk Higgs.