An updated analysis of radion-higgs mixing in the light of LHC data

TL;DR

This paper analyzes how radion-higgs mixing in warped extra-dimensional models is constrained by recent LHC and Tevatron data, focusing on the WW* decay channel and considering both scalar mass eigenstates and interference effects.

Contribution

It provides a comprehensive, updated analysis of radion-higgs mixing constraints using full WW* channel simulations and global data fitting, improving upon previous studies.

Findings

Exclusion contours in parameter space are derived from current collider data.

Regions consistent with 68% and 95% confidence levels are identified.

Implications for a second scalar with mass 110-600 GeV are discussed.

Abstract

We explore the constraints on the parameter space of a Randall-Sundrum warped geometry scenario, where a radion field arises out of the attempt to stabilise the radius of the extra compact spacelike dimension, using the most recent data from higgs searches at the Large Hadron Collider (LHC) and the Tevatron. We calculate contributions from both the scalar mass eigenstates arising from radion-higgs kinetic mixing in all important search channels. The most important channel to be affected is the decay via WW*, where no invariant mass peak can discern the two distinct physical states. Improving upon the previous studies, we perform a full analysis in the WW* channel, taking into account the effect of various cuts and interference when the two scalar are closely spaced. We examine both cases where the experimentally discovered scalar is either 'higgs-like' or 'radion-like'. The implications of a relatively massive scalar decaying into a pair of 125 GeV scalars is also included. Based on a global analysis of the current data, including not only a single 125 GeV scalar but also another one with mass over the range 110 to 600 GeV, we obtain the up-to-date exclusion contours in the parameter space. Side by side, regions agreeing with the data within 68% and 95% confidence level based on a \chi^2-minimisation procedure, are also presented.