Related papers: Naturalness of lepton non-universality and muon g-…
The discovery of a light Higgs boson means that whatever form new physics takes, it should keep stable the Higgs mass. Besides the well-known solutions to the naturalness problem (Supersymmetry, Conformal symmetry, Compositeness, etc),…
I review possible explanations of the muon g-2 anomaly in models with extended Higgs and matter sectors, focusing on extensions of the standard model and the two Higgs doublet model with vectorlike leptons. Predictions of these models,…
With the discovery of a particle that seems rather consistent with the minimal Standard Model Higgs boson, attention turns to questions of naturalness, fine-tuning, and what they imply for physics beyond the Standard Model and its discovery…
The minimal Type I see-saw model cannot explain the observed neutrino masses and the baryon asymmetry of the Universe via hierarchical thermal leptogenesis without ceding naturalness. We show that this conclusion can be avoided by adding a…
The LHC runs at 7 and 8 TeV have led to the discovery of the Higgs boson at 125 GeV which will remain as one of the major physics discoveries of our time. Another very important result was the surprising absence of any signals of new…
We present a supersymmetric extension of the Standard Model in which the new physics contributions to the anomalous magnetic moment of the muon can be more than an order of magnitude larger than in the minimal supersymmetric Standard Model.…
We study a predictive model for explaining the apparent deviation of the muon anomalous magnetic moment from the Standard Model expectation. There are no new scalars and hence no new hierarchy puzzles beyond those associated with the Higgs;…
$N$-naturalness is a novel solution to the electroweak hierarchy problem which posits $N$ copies of the Standard Model with varying Higgs mass-squared parameters. Reheating proceeds through a "reheaton" particle that deposits most of its…
Since its inception, no decisive departure from the predictions of Standard Model (SM) has been reported. But recently various experiments have observed few hints of possible departure from SM predictions in lepton flavor universality…
The hierarchy problem in the Standard Model is usually understood as both a technical problem of stability of the calculation of the quantum corrections to the masses of the Higgs sector and of the unnatural difference between the Planck…
The hierarchy between the mass parameter of the Higgs boson and larger mass scales becomes ever more puzzling as experiments explore higher energies. Neutral naturalness is the umbrella term for symmetry-based explanations for these…
We consider a flavour conserving two Higgs doublet model that consists of a type I (or X) quark sector and a generalized lepton sector where the Yukawa couplings of the charged leptons to the new scalars are not proportional to the lepton…
Supersymmetry is one of the most plausible extensions of the Standard Model, since it is well motivated by the hierarchy problem, supported by measurements of the gauge coupling strengths, consistent with the suggestion from precision…
We construct a simple theory in which the fine-tuning of the standard model is significantly reduced. Radiative corrections to the quadratic part of the scalar potential are constrained to be symmetric under a global U(4) x U(4)' symmetry…
We show that new physics explanations of the muon $g-2$ anomaly by the contributions of new leptons mediated by the standard model Higgs boson necessarily lead to large rates for $\mu^+ \mu^- \to hh$ and $\mu^+ \mu^- \to hhh$ irrespectively…
Imagine to discover a new fourth family of leptons at the Large Hadron Collider (LHC) but no signs of an associated fourth family of quarks. What would that imply? An intriguing possibility is that the new fermions needed to compensate for…
I present a model addressing coherently the naturalness problem of the electroweak scale and the observed pattern of deviations from the Standard Model in semi-leptonic decays of $B$ mesons. The Higgs and the two scalar leptoquarks…
We present some phenomenology of the Higgs sector of the Minimal $B-L$ U(1) Extension of the Standard Model at the Large Hadron Collider. In this model, the existence of an extra gauge boson ($Z'$) and an extra scalar (heavy Higgs) are…
The situation in particle physics after the discovery of the Higgs boson is discussed. Is the Standard Model complete? Are there still mysteries which have no answer? Answering these questions we consider the Higgs sector, the neutrino…
It has recently been pointed out that the mirror or twin Higgs model is more technically natural than the standard model, thus alleviating the ``little'' hierarchy problem. In this paper we generalise the analysis to models with an…