Related papers: Universality limits on bulk fermions
We propose a new non-universal $U(1)'$ extension of the standard model with the addition of three exotic quark singlets, two scalar singlets and one additional scalar doublet. We obtain family dependent couplings with a new $Z'$ boson in…
As the Higgs boson properties settle, the constraints on the Standard Model extensions tighten. We consider all possible new fermions that can couple to the Higgs, inspecting sets of up to four chiral multiplets. We confront them with…
We built an extended 2HDM theory with a spontaneously broken $U(1) _{X}$ global symmetry, where the tree level Universal Seesaw Mechanism generates the mass hierarchy of the Standard Model charged fermions and the Zee-Babu mechanism…
We consider the possibility that the neutral-current $B$ anomalies are due to radiative corrections generated by Yukawa interactions of quarks and leptons with new vector-like quark and lepton electroweak doublets and new Standard Model…
It is well known that the supersymmetric finite threshold effects can induce substantial corrections to the Standard Model fermion masses. This opens an alternative possibility to correct the problematic mass ratios of the lighter…
We present an overview of searches fo violation of lepton flavor universality with focus on low energy precision probes using pions, kaons, tau leptons, and nuclear beta decays. The current experimental results are reviewed, the theoretical…
We present a class of warped extra dimensional models whose flavor violating interactions are much suppressed compared to the usual anarchic case due to flavor alignment. Such suppression can be achieved in models where part of the global…
As a minimal theory of fermion masses we extend the SM by heavy vectorlike fermions, with flavor-anarchical Yukawa couplings, that mix with chiral fermions such that small SM Yukawa couplings arise from small mixing angles. This model can…
We study renormalizable extensions of the standard model that contain vector-like fermions in a (single) complex representation of the standard model gauge group. There are 11 models where the vector-like fermions Yukawa couple to the…
Based on Quantum Gravity arguments, it has been suggested that all kinetic terms of light particles below the UV cut-off could arise in the IR via quantum (loop) corrections. These loop corrections involve infinite towers of states becoming…
With a modest revision of the mass sector of the Standard Model, the systematics of the fermion masses and mixings can be fully described and interpreted as providing information on matrix elements of physics beyond the Standard Model. A…
We argue that extensions of the Standard Model (SM) with a warped extra dimension, which successfully address the hierarchy and flavor problems of elementary particle physics, can provide an elegant explanation of the 750 GeV diphoton…
Grand unified theories often predict unification of Yukawa couplings (e.g., $h_{b} = h_{\tau}$), and thus certain relations among fermion masses. The latter can distinguish these from models that predict only coupling constant unification.…
$U(1)^\prime$ extensions of the standard model with generation-dependent couplings to quarks and leptons are investigated as an explanation of anomalies in rare $B$-decays, with an emphasis on stability and predictivity up to the Planck…
We obtain contraints on three Universal Extra Dimensional models utilizing limits from the CMS Collaboration on W' production and decay into a single-top-quark final state. We find a weak constraint on the Minimal Universal Extra Dimensions…
We reconsider models of fermion masses and mixings based on a gauge anomalous horizontal U(1) symmetry. In the simplest model with a single flavon field and horizontal charges of the same sign for all Standard Model fields, only very few…
A brief review of the recent developments in the physics from extra dimensions is given with a focus on the effects of Kaluza-Klein excitations in the Standard Model sector. It is shown that the current accurate data on the Fermi constant…
Unitary random matrix ensembles Z_{n,N}^{-1} (\det M)^alpha exp(-N Tr V(M)) dM defined on positive definite matrices M, where alpha > -1 and V is real analytic, have a hard edge at 0. The equilibrium measure associated with V typically…
The flavour puzzle remains as one of the most intriguing enigmas of particle physics. In this thesis, we propose and study theories of flavour which generically hint to a multi-scale origin of flavour. First we explore the idea of…
We consider the Kaluza-Klein (KK) scenario in which only gravity exists in the bulk. Without the assumption of symmetric connection, the presence of brane fermions induces torsion. The result is a universal axial contact interaction that…