相关论文: The custodial symmetry
We present a simple and transparent method to study custodial symmetry in the Two-Higgs-Doublet Model. The method allows to formulate the basis independent, sufficient and necessary, conditions for the custodial symmetry of the scalar…
In the Standard Model for electroweak interactions, the Higgs sector is known to display a "custodial" symmetry protecting the mass relation m_{W^\pm}^2=m_{W_3}^2 from large corrections. When considering extensions of the scalar sector,…
We introduce a toy model implementing the proposal of using a custodial symmetry to protect the Zbb coupling from large corrections. This "doublet-extended standard model" adds a weak doublet of fermions (including a heavy partner of the…
I study, in the leptonic sector, the role of the $SU(2)_V$ custodial symmetry $\ti{\cal G}$ which was shown in ref. [1] to control the quantization of the electric charge in the $J=0$ mesonic sector. The electroweak theory is considered,…
We present a class of composite Higgs models arising from a warped extra dimension that can satisfy all the electroweak precision tests in a significant portion of their parameter space. A custodial symmetry plays a crucial role in keeping…
We introduce a toy model implementing the proposal of using a custodial symmetry to protect the Z b_L bbar_L coupling from large corrections. This "doublet-extended standard model" adds a weak doublet of fermions (including a heavy partner…
I introduce the idea of "Custodial Naturalness" to explain the origin of the electroweak (EW) scale hierarchy. Custodial Naturalness is based on classical scale invariance as well as an extension of the Standard Model (SM) scalar sector…
The new measurement of the $W$-boson mass from the CDF collaboration shows a significant tension with the Standard Model prediction. We quantify this discrepancy within a state-of-the-art analysis of electroweak precision data and…
The new measurement of the W boson mass from the CDF collaboration shows a significant tension with the Standard Model prediction, which evidences violation of custodial symmetry in the scalar sector. We study the scalar extensions of the…
We introduce a toy model implementing the proposal of using a custodial symmetry to protect the Zbb coupling from large corrections. This "doublet-extended standard model" adds a weak doublet of fermions (including a heavy partner of the…
We show that the extension of the approximate custodial $SU(2)_{L+R}$ global symmetry to all the Yukawa interactions of the standard model Lagrangian implies the introduction of sterile right-handed neutrinos and the seesaw mechanism in…
The concept of custodial symmetry, a residual symmetry that protects physical observables from large quantum corrections, has been a cornerstone of high-energy physics, but its experimental observation has remained unexplored. Building on…
We present "Custodial Naturalness" as a new mechanism to explain the separation between the electroweak (EW) scale and the scale of potential ultraviolet completions of the Standard Model (SM). We assume classical scale invariance as well…
Custodial Naturalness is a new symmetry-based idea to explain the large separation between the electroweak (EW) scale and ultraviolet completions of the Standard Model (SM). Classical scale invariance is combined with an enhanced…
We derive basis-independent, necessary and sufficient conditions for the custodial symmetry in N-Higgs-doublet models (NHDM) for N > 2, and apply them on some 3HDM examples.
Custodial Naturalness is a recently introduced idea that combines conformal and scalar-sector custodial symmetry to address the electroweak (EW) scale hierarchy problem of the Standard Model (SM). We introduce a new model that realizes…
Within the framework of the Standard Model, the scale of electroweak symmetry breaking is unstable to radiative corrections. We discuss two broad classes of models of new physics (one with a strongly interacting and the other with a…
In these lectures, I present an introduction to the theory and phenomenology of dynamical electroweak symmetry breaking.
We review the status of and recent developments in dynamical electroweak symmetry breaking, concentrating on the ideas of technicolour and top quark condensates. The emphasis is on the essential physical ideas and experimental implications…
Custodial symmetries are common in the Standard Model of particle physics. They arise when quantum corrections to a parameter are proportional to the parameter itself. Here, we show that a custodial symmetry of the chiral type is also…