Higgs production and decay in models of a warped extra dimension with a bulk Higgs

Abstract

Warped extra-dimension models in which the Higgs boson is allowed to propagate in the bulk of a compact AdS 5 space are conjectured to be dual to models featuring a partially composite Higgs boson. They offer a framework with which to investigate the implications of changing the scaling dimension of the Higgs operator, which can be used to reduce the constraints from electroweak precision data. In the context of such models, we calculate the cross section for Higgs production in gluon fusion and the H → γγ decay rate and show that they are finite (at one-loop order) as a consequence of gauge invariance. The extended scalar sector comprising the Kaluza-Klein excitations of the Standard Model scalars is constructed in detail. The largest effects are due to virtual KK fermions, whose contributions to the cross section and decay rate introduce a quadratic sensitivity to the maximum allowed value y * of the random complex entries of the 5D anarchic Yukawa matrices. We find an enhancement of the gluon-fusion cross section and a reduction of the H → γγ rate as well as of the tree-level Higgs couplings to fermions and electroweak gauge bosons. We perform a detailed study of the correlated signal strengths for different production mechanisms and decay channels as functions of y * , the mass scale of Kaluza-Klein resonances and the scaling dimension of the composite Higgs operator.

Impact of warped extra dimensions on the dipole coefficients in b → sγ transitions

“…It is well known that quantum fields can be strictly localized on orbifold fixed points, and in such a scenario the quantity ∆ h can indeed be infinite or arbitrarily large. Similar to the case of Higgs production via gluon fusion [29,[35][36][37][38][39][40][41][42][43][44][45], we will find that our results for the Higgs contributions to the b → sγ and b → sg dipole coefficients are sensitive to details of the localization mechanism. For these contributions we sometimes extend our results to the case of a so-called narrow bulk-Higgs scenario, where the Higgs field lives in the bulk with an inverse width such that M KK ∆ h Λ TeV [29].…”

5D perspective on Higgs production at the boundary of a warped extra dimension

“…(5.32) and (7.19). On the contrary, the results for a generic bulkHiggs model, in which the width of the Higgs profile is not parametrically small, depend in a complicated way on the 5D fermion masses and the shape of the Higgs profile [44].…”

“…The features of the Higgs profile can then be resolved by the high-momentum states in the effective theory, and indeed one finds that high-mass KK fermions make sizable contributions. In the general case, the gluon fusion amplitude in an RS model with a bulk-Higgs field depends in a complicated way on the shapes of the Higgs and fermion profiles along the extra dimension (see [20] for an approximate treatment; a more detailed analysis will be presented in [44]). However, we find that for a narrow Higgs profile, defined by the relation…”

Warped flavor symmetry predictions for neutrino physics

“…It is well known that models with a brane-localized Higgs and no custodial symmetry suffer from large constraints imposed by electroweak precision tests [37,38]. However, the tensions with electroweak precision tests [39][40][41][42] and flavour physics [42][43][44][45] can be significantly reduced in the case of a 5D Higgs field living in the bulk, offering a new elegant explanation for the the tiny neutrino masses [46,47]. That is to say, a SU(2) L doublet bulk Higgs field…”