Gauge Boson Resonance Research Articles

Domain-Wall Standard Model in non-compact 5D and LHC phenomenology

We propose a framework to construct “Domain-Wall Standard Model” in a non-compact 5-dimensional spacetime, where all the Standard Model (SM) fields are localized in certain domains of the 5th dimension and the SM is realized as a 4-dimensional effective theory without any compactification for the 5th dimension. In this context, we investigate the collider phenomenology of the Kaluza–Klein (KK) modes of the SM gauge bosons and the current constraints from the search for a new gauge boson resonance at the Large Hadron Collider Run-2. The couplings of the SM fermions with the KK-mode gauge bosons depend on the configuration of the SM fermions in the 5-dimensional bulk. This “geometry” of the model can be tested at the future Large Hadron Collider experiment, once a KK-mode of the SM gauge boson is discovered.

Phenomenology of strongly coupled chiral gauge theories

A sector with QCD-like strong dynamics is common in models of non-standard physics. Such a model could be accessible in LHC searches if both confinement and big-quarks charged under the confining group are at the TeV scale. Big-quark masses at this scale can be explained if the new fermions are chiral under a new $U(1)^\prime$ gauge symmetry such that their bare masses are related to the $U(1)^\prime$-breaking and new confinement scales. Here we present a study of a minimal GUT-motivated and gauge anomaly-free model with implications for the LHC Run 2 searches. We find that the first signatures of such models could appear as two gauge boson resonances. The chiral nature of the model could be confirmed by observation of a $Z^\prime \gamma$ resonance, where the $Z^\prime$ naturally has a large leptonic branching ratio because of its kinetic mixing with the hypercharge gauge boson.

Phenomenology of the 3-3-1-1 model

We discuss a new SU(3)_C X SU(3)_L X U(1)_X X U(1)_N (3-3-1-1) gauge model that overhauls the theoretical and phenomenological aspects of the known 3-3-1 models. Additionally, we sift the outcome of the 3-3-1-1 model from precise electroweak bounds to dark matter observables. The mass spectra of the scalar and gauge sectors are diagonalized when the scale of the 3-3-1-1 breaking is compatible to that of the ordinary 3-3-1 breaking. All the interactions of the gauge bosons with the fermions and scalars are obtained. The 3-3-1-1 model provides two dark matters which are stabilized by the W-parity conservation: one fermion which may be either a Majorana or Dirac fermion and one complex scalar. We conclude that in the fermion dark matter setup the Z_2 gauge boson resonance sets the dark matter observables, whereas in the scalar one the Higgs portal dictates them. The standard model GIM mechanism works in the model because of the W-parity conservation. Hence, the dangerous flavor changing neutral currents due to the ordinary and exotic quark mixing are suppressed, while those coming from the non-universal couplings of the Z_2 and Z_N gauge bosons are easily evaded. Indeed, the K^0-\bar{K}^0 and B^0_s-\bar{B}^0_s mixings limit m_{Z_{2,N}}>2.037 TeV and m_{Z_{2,N}}>2.291 TeV, respectively, while the LEPII searches provide a quite close bound m_{Z_{2,N}}>2.737 TeV. The violation of the CKM unitarity due to the loop effects of the Z_2 and Z_N gauge bosons is negligible. [Full abstract is given in the text.]

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

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.

Precision calculations for the Higgs decays H → ZZ/WW → 4 leptons

Extending earlier work, we provide predictions obtained with the Monte Carlo generator PROPHECY4f for the decays H → ZZ/WW → 4l including the complete electroweak O ( α ) corrections and some higher-order improvements. The gauge-boson resonances are described in the complex-mass scheme. Here, particular attention is paid to a comparison of different final states with identical charges, such as e + e − μ + μ − and μ + μ − μ + μ − .

Electroweak corrections to leptons

We provide predictions for the decays H → ZZ → 4 ℓ and H → WW → 4 ℓ including the complete electroweak O ( α ) corrections and improvements by higher-order final-state radiation and two-loop corrections proportional to G μ 2 M H 4 . The gauge-boson resonances are described in the complex-mass scheme. We find corrections at the level of 1–8% for the partial widths.

Cartography with accelerators: Locating fermions in extra dimensions at future lepton colliders

In the model of Arkani-Hamed and Schmaltz the various chiral fermions of the Standard Model(SM) are localized at different points on a thick wall which forms an extra dimension. Such a scenario provides a way of understanding the absence of proton decay and the fermion mass hierarchy in models with extra dimensions. In this paper we explore the capability of future lepton colliders to determine the location of these fermions in the extra dimension through precision measurements of conventional scattering processes both below and on top of the lowest lying Kaluza-Klein gauge boson resonance. We show that for some classes of models the locations of these fermions can be very precisely determined while in others only their relative positions can be well measured.