Search for massive resonances decaying into pairs of boosted bosons in semi-leptonic final states at s $$ \sqrt{s} $$ = 8 TeV

Abstract

A search for new resonances decaying to WW, ZZ, or WZ is presented. Final states are considered in which one of the vector bosons decays leptonically and the other hadronically. Results are based on data corresponding to an integrated luminosity of 19.7 fb −1 recorded in proton-proton collisions at √ s = 8 TeV with the CMS detector at the CERN LHC. Techniques aiming at identifying jet substructures are used to analyze signal events in which the hadronization products from the decay of highly boosted W or Z bosons are contained within a single reconstructed jet. Upper limits on the production of generic WW, ZZ, or WZ resonances are set as a function of the resonance mass and width. We increase the sensitivity of the analysis by statistically combining the results of this search with a complementary study of the all-hadronic final state. Upper limits at 95% confidence level are set on the bulk graviton production cross section in the range from 700 to 10 fb for resonance masses between 600 and 2500 GeV, respectively. These limits on the bulk graviton model are the most stringent to date in the diboson final state.Keywords: Hadron-Hadron Scattering, Particle and resonance production, Jet substructure In many theoretical extensions of the SM, the spontaneous breaking of the EW symmetry is associated with new strong dynamics appearing at the TeV scale. For instance, the origin of the new dynamics may be due to new interactions [10][11][12] or a composite Higgs boson [13][14][15]. These extensions of the SM predict the existence of new resonances coupling to pairs of massive vector bosons (VV, where V = W or Z). Results from previous direct searches at and ATLAS [20][21][22][23], and from indirect bounds from the EW sector and from flavor physics [24,25] generally place lower limits on the masses of these VV resonances above the TeV scale.Models extending the number of spatial dimensions are of particular interest in the attempt to explain the apparently large difference between the EW and the gravitational scale. Some of these models predict the existence of a so-called tower of Kaluza-Klein (KK) excitations of a spin-2 boson, the KK graviton. The WW and ZZ channels are some of the possible decay modes of the Randall-Sundrum (RS) graviton [26] in warped extra dimension models. The original RS model (here denoted as RS1) can be extended to the bulk graviton (G bulk ) model, which addresses the flavor structure of the SM through localization of fermions in the warped extra dimension [27][28][29]. In this scenario, coupling of the graviton to light fermions is highly suppressed and the decays into photons are negligible. On the other hand, the production of gravitons from gluon fusion and their decays into a pair of massive gauge bosons can be sizable at hadron colliders. The model has two free parameters: the mass of the first mode of the KK bulk graviton, M G , and the ratio k/M Pl , where k is the unknown curvature scale of the extra dimension, and M Pl ≡ M Pl / √ 8π is the reduced Planck mass. Previous di...

Large mass hierarchies from strongly-coupled dynamics

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Derivative interactions and perturbative UV contributions in N Higgs doublet models

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A Heavy Scalar at the LHC from Vector-Boson Fusion

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