Exploring Drell-Yan signals from the 4D Composite Higgs Model at the LHC

Abstract

We study the phenomenology of Drell-Yan processes at the Large Hadron Collider for the case of both the neutral and charged current channels within a recently proposed 4-Dimensional formulation of the Minimal Composite Higgs Model. We estimate the integrated and differential event rates at the CERN machine, assuming 14 TeV and data samples of ${\cal O}(100 {\rm{fb}}^{-1})$, as at lower energy and/or luminosity event rates are prohibitively small. We pay particular attention to the presence of multiple resonances in either channel, by showing that in certain region of parameter space some of these can be distinguishable and experimentally accessible in the invariant and/or transverse mass distribution, sampled in either the cross section, the forward-backward asymmetry or both. At the same time, we assess the indirect impact onto the line-shape of the emerging gauge boson resonances, both neutral and charged, of additional heavy fermionic states present in the spectrum of the model. Finally, we show how to exploit in the kinematic selection the fact that the extra neutral and charged gauge boson resonances in composite Higgs models are correlated in mass. Such results rely on a parton level study including a statystical error analysis.Comment: 42 pages, 19 figures, changes for publication in JHE

Drell-Yan production of multi Z ′-bosons at the LHC within Non-Universal ED and 4D Composite Higgs Models

“…Neglecting the SO(4) explicit breaking, the masses of the SO(4) and SO(5)/SO(4) resonances are given 2 Actually, in order to guarantee a correct hypercharge assignment to the SM fermions, an extra U(1)X group needs to be added, bringing to 5 the number of neutral resonances. Under the assumption of equal couplings for the SO(5) and U(1)X groups (adopted in [35] as a specific parameter choice of the model described in [34]), two of the mass eigenstates can be redefined to be the ones aligned with the hypercharge direction, T Y = T 3R + T X , and the orthogonal combination respectively. Under this assumption, the latter will not couple to the constituents of the proton and we will therefore neglect it throughout our analysis (this happens in the minimal realisation where just the third generation of fermions mixes with the extended sector).…”

“…These EWSB effects will be the only source of corrections to the mass of the coset resonances, which will retain therefore a mass of √ 2f g ρ , modulo corrections of order ξ. The squared masses of the interested gauge bosons at O(ξ) are given by [35]:…”

“…We use benchmark F of table 2 (which is essentially the (f) point corresponding to figure 12 of ref. [35]: see tables 19 and 22 therein for its features). We take the ratio x = Γ Z 3 /M Z 3 to be 5%.…”

Bounding wide composite vector resonances at the LHC

“…Yet, limits from such direct searches greatly weaken within a regime where ρ resonances decay channels into top partner pairs kinematically open up. This is a direct consequence of significantly suppressed ρ 0,± branching ratios (BRs) into SM states due to the strong intercomposite coupling constant g ρ g SM [18,19]. In this case the strongest bound on EW spin one states is currently set by indirect limits from the S parameter [19].…”

Higgs-Z-photon coupling from effect of composite resonances

“…It is emphasized in ref. [16,17], that one of the important approaches to probe the signatures of heavy vector bosons is through the Drell-Yan and vector-boson-fusion (VBF) production processes. In our phenomenology model, assuming that all the fermions are completely fundamental, the di-bosons final state should be particularly explored other than the leptonic channel and the multi-jets channel as they dominate in the branching ratios of both the heavy neutral and charged vector bosons.…”