Spontaneous symmetry breaking in quasi-super-renormalizable models (original) (raw)
Renormalization in supersymmetric models
There are reasons to believe that the Standard Model is only an effective theory, with new Physics lying beyond it. Supersymmetric extensions are one possibility: they address some of the Standard Model's shortcomings, such as the instability of the Higgs boson mass under radiative corrections. In this thesis, some topics related to the renormalization of supersymmetric models are analyzed. One of them is the automatic computation of the Lagrangian and the renormalization group equations of these models, which is a hard and error-prone process if carried out by hand. The generic renormalization group equations themselves are extended so as to include those models which have more than a single abelian gauge factor group. Such situations can occur in grand unified theories, for example. For a wide range of SO(10)-inspired supersymmetric models, we also show that the renormalization group imprints on sparticle masses some information on the higher energies behavior of the models. F...
Nuclear Physics B, 2016
In this paper, we revisit the issue intensively studied in recent years on the generation of terms by radiative corrections in models with broken Lorentz symmetry. The algebraic perturbative method of handling the problem of renormalization of the theories with Lorentz symmetry breaking, is used. We hope to make clear the Symanzik's aphorism: "Whether you like it or not, you have to include in the lagrangian all counter terms consistent with locality and power-counting, unless otherwise constrained by Ward identities." 1
Vacuum instabilities in models with spontaneous symmetry breaking
Nuclear Physics B, 1980
Adopting as a reference a simple mode1 with spontaneously broken symmetry we show that the extra massless field present in the tree approximation in addition to the true Goldstone bosons may induce, through the radiative corrections to its vacuum expectation value, infrared effects which are not compensable without spoiling the symmetry itself. We further extend the analysis to generic lagrangian field models with spontaneous symmetry breaking and prove that the only constraint to their renormalizability arises from the radiative corrections to the vacuum expectation value of the massless fields, except for the true Goldstone bosons which never induce such pathologies.
Dynamical symmetry breaking in supersymmetric and gauge theories
Nuclear Physics B, 2000
We find the phase and flavor symmetry breaking pattern of each N = 1 supersymmetric vacuum of SU (n c) and U Sp(2n c) gauge theories, constructed from the exactly solvable N = 2 theories by perturbing them with small adjoint and generic bare hypermultiplet (quark) masses. In SU (n c) theories with n f ≤ n c the vacua are labelled by an integer r, in which the flavor U (n f) symmetry is dynamically broken to U (r) × U (n f − r) in the limit of vanishing bare hyperquark masses. In the r = 1 vacua the dynamical symmetry breaking is caused by the condensation of magnetic monopoles in the n f representation. For general r, however, the monopoles in the n f C r representation, whose condensation could explain the flavor symmetry breaking but would produce too-many Nambu-Goldstone multiplets, actually "break up" into "magnetic quarks": the latter with nonabelian interactions condense and induce confinement and dynamical symmetry breaking. In U Sp(2n c) theories with n f ≤ n c + 1, the flavor SO(2n f) symmetry is dynamically broken to U (n f), but with no description in terms of a weakly coupled local field theory. In both SU (n c) and U Sp(2n c) theories, with larger numbers of quark flavors, besides the vacua with these properties, there exist also vacua in free magnetic phase, with unbroken global symmetry.
Physical Review D, 1994
In this paper we summarize the minimal supersymmetric standard model as well as the renormalization group equations of its parameters. We proceed to examine the feasability of the model when the breaking of supersymmetry is parametrized by the soft terms suggested by supergravity theories. In such models, the electroweak symmetry is exact at tree level and is broken spontaneously at one loop order. We make the additional assumption that the GUT-inspired relation m b = m τ be valid at the scale where the gauge coupling constants unify, which constrains the value of the top quark mass. For all types of soft breaking terms expected in supergravity theories, we present the results of numerical runs which yield electroweak breaking at the required scale. These yield not only the allowed ranges for the soft supersymmetry breaking parameters, but also the value of the supersymmetric partner' masses. For example in the strict no-scale model, in which global supersymmetry breaking arises solely from soft gaugino masses, we find that M t can be no heavier than ∼ 127 GeV.
Spontaneous Breaking of Scale Invariance and Supersymmetric Models at Finite Temperature
International Journal of Modern Physics A, 2005
The phase structure of a supersymmetric, vector O(N) symmetric model at Large N in three dimension is presented. At zero temperature it reveals spontaneous breaking of scale invariance with no explicit breaking. When the attracting force between the massive quanta, bosons and fermions, is tuned to a certain critical value one finds massless bound states, a Goldstone boson and a Goldstone fermion, associated with the spontaneous breaking of scale invariance (massless dilaton and dilatino). The effect of finite temperature on this phenomenon is elucidated. Expectation values of the energy momentum tensor are calculated at zero and finite temperatures. The phase structure is unveiled in the limit N → ∞. We point out that at a certain critical value of the coupling constant the trace of the energy momentum tensor vanishes at all temperatures.
Spontaneous Symmetry Breaking and Its Pattern of Scales
Symmetry
Spontaneous Symmetry Breaking (SSB) in λΦ4 theories is usually described as a 2nd-order phase transition. However, most recent lattice calculations indicate instead a weakly 1st-order phase transition as in the one-loop and Gaussian approximations to the effective potential. This modest change has non-trivial implications. In fact, in these schemes, the effective potential at the minima has two distinct mass scales: (i) a first mass mh associated with its quadratic curvature and (ii) a second mass Mh associated with the zero-point energy which determines its depth. The two masses describe different momentum regions in the scalar propagator and turn out to be related by Mh2∼mh2ln(Λs/Mh), where Λs is the ultraviolet cutoff of the scalar sector. Our lattice simulations of the propagator are consistent with this two-mass picture and, in the Standard Model, point to a value Mh∼700 GeV. However, despite its rather large mass, this heavier excitation would interact with longitudinal W’s an...
Spontaneous Breaking of Supersymmetry in Cosmological Models and Supergravity Theories
Modern Physics Letters A, 1999
In this work we have constructed the most general action for a set of complex homogeneous scalar supermultiplets interacting with the scale factor in the supersymmetric FRW model. It is shown that the local conformal time supersymmetry leads to a scalar field potential defined in terms of the Kahler potential and superpotential in the same combination as in supergravity (or effective superstring) theories. This scalar field potential depends on an arbitrary parameter Q which is not fixed by conformal time supersymmetry and induces the spontaneous breaking of supersymmetry in supergravity theories.
Dynamical breaking of symmetries beyond the standard model and supergeometry
Physica Scripta, 2019
Group theoretical realizations containing the electroweak sector of the Standard Model are discussed from the supersymmetry point of view. Dynamical breaking of the symmetry is performed and the corresponding quadratic (super Yang-Mills) Lagrangian is obtained. Supercoherent states of the Klauder-Perelomov type are defined to enlarge the symmetry taking into account the geometry of the coset based in the simplest supergroup SU (2 | 1) as the structural basis of the electroweak sector of the SM. The extended model is superintegrable and the superconnection in the odd part takes a dynamical character. The physical and geometrical implications of the additional degrees of freedom interpreted as a hidden sector of the representation are briefly discussed.