Related papers: Goldstone Bosons
In this work, a novel mechanism for spontaneous symmetry breaking is presented. This mechanism avoids quadratic divergencies and is thus capable of addressing the hierarchy problem in gauge theories. Using the scale-dependent effective…
The Minimal Linear $\sigma$ Model is a useful theoretical laboratory. One can investigate in a perturbative renormalisable model the properties of the Higgs boson as a pseudo-Goldstone boson, the phenomenological effects of the radial mode…
The implications of the hidden, spontaneously broken symmetry for the properties of the sound waves of a solid are analyzed. Although the discussion does not go beyond standard wisdom, it presents some of the known results from a different…
I review aspects of the theory of the weak interaction in a set of lectures originally presented at the 2016 CERN-JINR European School of Particle Physics. The topics discussed are: (1) the experimental basis of the V-A structure of the…
We adapt the Goldstone theorem to study spontaneous symmetry breaking in relativistic theo- ries at finite charge density. It is customary to treat systems at finite density via non-relativistic Hamiltonians. Here we highlight the…
In the first part of the talk, I discussed the nature of the effective theory that describes the properties of the pion-nucleon-interaction at low energies, using the static model as a starting point. In the second part, I then pointed out…
In quantum field theory there is now a well developed technique, effective field theory, which allows one to obtain low energy quantum predictions in ``non-renormalizable'' theories, using only the degrees of freedom and interactions…
We consider the low-energy collective excitations at finite temperature of Bose--Einstein condensed gases (and liquids as well). A most general model-independent effective Lagrangian is written down according to a prescription obtained from…
In this thesis I study applications of effective field theories to understand aspects of QCD jets and their substructure at the Large Hadron Collider. In particular, I introduce an observable, $D_2$, which can be used for distinguishing…
The phenomenon of spontaneous symmetry breaking is well known. It is known to be accompanied with the appearance of the `Goldstone boson'. In this paper we construct the canonical coordinates of the Goldstone boson, for quantum spin systems…
Effective field theories encode the predictions of a quantum field theory at low energy. The effective theory has a fairly low ultraviolet cutoff. As a result, loop corrections are small, at least if the effective action contains a term…
Atomic high-precision measurements have become a competitive and essential technique for tests of fundamental physics, the Standard Model, and our theory of gravity. It is therefore self-evident that such measurements call for a consistent…
The main elements and methods of chiral perturbation theory, the effective field theory of the Standard Model below the scale of spontaneous chiral symmetry breaking, are summarized. Applications to the interactions of mesons and baryons at…
We prove a Goldstone Theorem in thermal relativistic quantum field theory, which relates spontaneous symmetry breaking to the rate of space-like decay of the two-point function. The critical rate of fall-off coincides with that of the…
Effetive field theory is believed to provide a useful framework for describing low-energy nuclear phenomena in a model-independent fashion. I give here a brief account of the basic features of this approach, some of its latest developments,…
These lectures provide an introduction to the basic ideas and methods of Effective Field Theory, and a description of a few interesting phenomenological applications in particle physics. The main conceptual foundations are discussed in…
Standard Model (SM) of particle physics has achieved enormous success in describing the interactions among the known fundamental constituents of nature, yet it fails to describe phenomena for which there is very strong experimental…
It was recently argued that certain relativistic theories at finite density can exhibit an unconventional spectrum of Goldstone excitations, with gapped Goldstones whose gap is exactly calculable in terms of the symmetry algebra. We confirm…
The mechanism of spontaneous symmetry breaking in quantum systems is briefly reviewed, rectifying part of the standard wisdom on logical and mathematical grounds. The crucial role of the localization properties of the time evolution for the…
In this talk I review an effective field theory that has been developed for processes with energetic hadrons, referred to as the Soft-Collinear Effective Theory. After outlining properties of the effective theory I briefly discuss its…