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In this dissertation, we present work towards characterizing various conformal and nearly conformal quantum field theories nonperturbatively using a combination of numerical and analytical techniques. A key area of interest is the conformal…
Singlet scalar Dark Matter can naturally arise in composite Higgs models as an additional stable pseudo-Nambu-Goldstone boson. We study the properties of such a candidate in a model based on $SU(6)/SO(6)$, with the light quark masses…
SU(2) gauge theory coupled to massless fermions in the adjoint representation is quantized in light-cone gauge by imposing the equal-time canonical algebra. The theory is defined on a space-time cylinder with "twisted" boundary conditions,…
We describe a novel variation of the mirror Twin Higgs model in which the color gauge group in both sectors is extended to SU(4$)_c$ and spontaneously broken to SU(3$)_c$ exclusively in the visible sector. Through this process, the mirror…
The 't Hooft and Corrigan-Ramond limits of massless one-flavor QCD consider the two Weyl fermions to be respectively in the fundamental representation or the two index antisymmetric representation of the gauge group. We introduce a limit in…
We present a major update on our investigations of SU(2) gauge theory with one Dirac flavor in the adjoint representation on the lattice. In particular we consider larger volumes, as well as four different values of the gauge coupling. We…
We consider $SU(N)$ Yang-Mills theory with massless chiral fermions in a complex representation of the gauge group. The main emphasis is on the so-called hybrid psi-chi-eta model. The possible patterns of realization of the continuous…
We consider a new physics possibility at the colliders: the observation of TeV scale massive vector bosons in the non-adjoint representations under the Standard Model (SM) gauge symmetry. To have a unitary and renormalizable theory, we…
Four fermion interactions appear in many models of Beyond Standard Model physics. In Technicolour and composite Higgs models Standard Model fermion masses can be generated by four fermion terms. They are also expected to modify the dynamics…
We describe a new method to determine non-perturbatively the beta function of a gauge theory using lattice simulations in the p-regime of the theory. This complements alternative measurements of the beta function working directly at zero…
An effective theory is proposed, combining the standard gauge group $SU(3)_{C}\otimes SU(2)_{L}\otimes U(1)_{Y}$ with a horizontal discrete symmetry. By assigning appropriate charges under this discrete symmetry to the various fermion…
We consider the impact of colored scalars that can couple directly to matter fields on the recently measured h to gamma gamma excess. Among all possible candidates only scalar states transforming as (8, 2,1/2) and (6,3,1/3) under the…
The dilaton low-energy effective field theory (EFT) of an emergent light scalar is probed in the paradigm of strongly coupled near-conformal gauge theories. These studies are motivated by models which exhibit small $\beta$-functions near…
We investigate the spectrum and IR properties of the SU(3) "sextet" model with two Dirac fermions in the two-index symmetric representation via lattice simulations. This model is a prime candidate for a realization of Walking Technicolor,…
A light scalar $\phi$ with mass $\lesssim 1$ GeV and muonic coupling $\mathcal{O}(10^{-3})$ would explain the 3.5 $\sigma$ discrepancy between the Standard Model (SM) muon $g-2$ prediction and experiment. Such a scalar can be associated…
We apply Schroedinger functional methods to two gauge theories with fermions in two-index representations: the SU(3) theory with Nf=2 adjoint fermions, and the SU(4) theory with Nf=6 fermions in the two-index antisymmetric representation.…
We explore the possibility that the interactions of a light scalar singlet, which mixes with the Standard Model~(SM) Higgs, also receive other UV contributions of comparable size. We focus, in particular, on the flavor aligned limit, where…
SU(2) gauge theory coupled to massless fermions in the adjoint representation is quantized in light-cone gauge by imposing the equal-time canonical algebra. The theory is defined on a space-time cylinder with "twisted" boundary conditions,…
The functional integral for QCD is reformulated by introducing explicitly an integration over the fluctuations of composite quark-antiquark bound states. Chiral symmetry breaking by the color singlet scalar field induces masses for the…
We present a study of spectroscopy of SU(4) lattice gauge theory coupled to two flavors of Dirac fermions in the anti-symmetric two index representation. The fermion representation is real, and the pattern of chiral symmetry breaking is…