Related papers: Naturalness Under Stress
We revisit the various measures of naturalness for models of weak scale supersymmetry including 1. electroweak (EW) naturalness, 2. naturalness via sensitivity to high scale parameters (EENZ/BG), 3. sensitivity of Higgs soft term due to…
We present an economical theory of natural electroweak symmetry breaking, generalizing an approach based on deconstruction. This theory is the smallest extension of the Standard Model to date that stabilizes the electroweak scale with a…
Assuming the presence of physics beyond the Standard Model (SM) with a characteristic scale M ~ O(10) TeV, we investigate the naturalness of the Higgs sector at scales below M using an effective field theory (EFT) approach. We obtain the…
Particle physics is sometimes described as going through a crisis, notably because of the continued lack of discovery of physics beyond the Standard Model, despite the LHC having operated at close to maximal energy for some years now. Here,…
Many extensions of the Standard Model postulate the existence of new weakly coupled particles, the top partners, at or below the TeV scale. The role of the top partners is to cancel the quadratic divergence in the Higgs mass parameter due…
These lectures describe why one believes there is physics beyond the Standard Model and review the expectations of three alternative explanations for the Fermi scale. After examining constraints and hints for beyond the Standard Model…
The reader surely knows what particles physics is about: finding building blocks of nature that appear elementary at a given time and study their interactions - so why in the world this essay? The problem is how to arrive at a fundamental…
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…
We quantify the extent to which naturalness is lost as experimental lower bounds on the Higgs boson mass increase, and we compute the natural upper bound on the lightest supersymmetric Higgs boson mass. We find that it would be unnatural…
Recently a new class of models has emerged that addresses the naturalness problem of a light Higgs boson. In these ''little Higgs'' models, the Standard Model Higgs boson is a pseudo-Nambu-Goldstone boson of an approximate global symmetry.…
The search for the left-handed $W^{\pm}$ bosons, the proposed quanta of the weak interaction, and the Higgs boson, which spontaneously breaks the symmetry of unification of electromagnetic and weak interactions, has driven…
Although the Higgs particle is at the centre-stage of the Standard Model of particle physics and in many other related models, it has not been experimentally found so far. One of the major objectives of the Large Hadron Collider experiments…
We review the theoretical underpinning of the Higgs mechanism of electroweak symmetry breaking and the experimental status of Higgs measurements from a pedagogical perspective. The possibilities and motivations for new physics in the…
The properties of the Higgs potential are determined by three parameters: the mass parameter, the quartic self-coupling, and a constant term. Remarkably, all three of these parameters seem subject to a significant amount of fine-tuning. All…
Symmetries in the Physical Laws of Nature lead to observable effects. Beyond regularities and conserved magnitudes, the last decades in Particle Physics have seen the identification of symmetries, and their well defined breaking, as the…
We analyze focus points in supersymmetric theories, where a parameter's renormalization group trajectories meet for a family of ultraviolet boundary conditions. We show that in a class of models including minimal supergravity, the up-type…
In any theory it is unnatural if the observed parameters lie very close to special values that determine the existence of complex structures necessary for observers. A naturalness probability, P, is introduced to numerically evaluate the…
The basic aim of physics studies at the LHC is to unravel the mechanism responsible for the spontaneous symmetry breaking in the Standard Model (SM). In the currently accepted theoretical picture, this translates into finding `direct'…
Using a four fermion interaction Lagrangian, we demonstrate that the spontaneous breaking of vector symmetries requires the existence of a light (comparing with the heavy fermion mass) scalar particle and the low energy effective theory…
Depending on the Higgs-boson and top-quark masses, $M_H$ and $M_t$, the effective potential of the Standard Model can develop a non-standard minimum for values of the field much larger than the weak scale. In those cases the standard…