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A. L. M. A. Nogueira

Publications and source records attributed to A. L. M. A. Nogueira.

11 recordsLinked to original sources

A Supersymmetric Extension of Axionic Electrodynamics: From Axions and Photons to Axinos and Photinos

In this contribution, we investigate a supersymmetric effective extension of Axionic Electrody- namics by adopting the superspace/superfield approach. Rather than focusing on UV-complete axion models, our goal is to analyze how supersymmetry modifies the dynamical and propagat- ing sectors of axion electrodynamics at the effective-field-theory level. In terms of component fields, the resulting Lagrangian describes the interactions among the axion, the photon, and their respective supersymmetric partners, the axino, the saxion and the photino. Supersymmetry in- duces new fermionic self-interactions and a non-polynomial interaction involving the axino, the photino, and the saxion. An interesting aspect to be highlighted is the appearance of fermionic bilinear contributions involving the photino to both the permittivity and permeability tensors of the constitutive relations. We also pay special attention to the dispersion relations in both the bosonic and fermionic sectors, and analyze the effective masses of the different particles in the presence of an external magnetic background, which induces supersymmetry breaking. Finally, with the help of numerical methods, we identify a class of axionic and electromagnetic-field configurations with interesting profiles of the magnetic field.

hep-ph↗

A supersymmetric model for graphene

In this work, we focus on the fermionic structure of the low-energy excitations of graphene (a monolayer of carbon atoms) to propose a new supersymmetric field-theoretic model for this physical system. In the current literature, other proposals for describing graphene physics have been contemplated at the level of supersymmetric quantum mechanics. Also, by observing the inhomogeneities between neighbor carbon atoms, Jackiw {\it et al.} have set up an interesting chiral Abelian gauge theory. We show in this paper that our formulation encompasses models discussed previously as sectors of an actually richer (supersymmetric) planar gauge model. Possible interpretations for the fields involved in the present graphene model are proposed and the question of supersymmetry breaking is discussed.

hep-th↗

Modeling the dynamics of single-bubble sonoluminescence

Sonoluminescence (SL) is the phenomenon in which acoustic energy is (partially) transformed into light. It may occur by means of many or just one bubble of gas inside a liquid medium, giving rise to the terms multi-bubble- and single-bubble sonoluminescence (MBSL and SBSL). In the last years some models have been proposed to explain this phenomenon, but there is still no complete theory for the light emission mechanism (especially in the case of SBSL). In this work, we will not address this more complicated particular issue, but only present a simple model describing the dynamical behaviour of the sonoluminescent bubble, in the SBSL case. Using simple numerical techniques within the software Matlab, we discuss solutions considering various possibilities for some of the parameters involved: liquid compressibility, superficial tension, viscosity, and type of gas. The model may be used as an introductory study of sonoluminescence in physics courses at undergraduate or graduate levels, as well as a quite clarifying example of a physical system exhibiting large nonlinearity.

physics.ed-ph↗

Vortex Solutions and a Novel Role for R-parity in an N=2-Supersymmetric Model for Graphene

In a previous work, we have been able to settle Jackiw's et al. chiral gauge theory for Dirac fermions in graphene in an N=1 supersymmetric framework, using a tau3-QED prescription, defined by means of a single pair of gauge charged superfields, but without preserving a global phase symmetry associated to the electric charge. In the present work, we propose another N=1-generalisation which indeed preserves this symmetry, namely, a straightforward extension built upon a set of two pairs of (chiral) gauge-charged superfields plus an extra pair of electrically neutral superfields. We then further proceed to establish, via a dimensional reduction procedure, an N=2 extension, allowing for the identification of non-perturbative features, as we put forward Bogomol'nyi equations and obtain vortex-like solutions saturating a topologically non-trivial bound. Remarkably, the bosonic projection of the N=2 functional space onto the saturated regime analysed herewith reveals to be free from extra scalar degrees of freedom that would otherwise demand a phenomenological interpretation. The investigation of Jackiw's model within an N=2 complex superspace is also motivated by the assumption that an R-parity-like symmetry could provide a route to incorporate the global phase-fermion number invariance as an external-like symmetry of the theory, thus associating the electric charge in graphene to the complex covariance (super-)space for the N=2-D=3 setup. We prove such a hypothesis to be realisable, as we build up the model endowed with all the symmetries required to further extend Jackiw's chiral gauge theory.

hep-th↗

On the Integrability and Chaos of an N=2 Maxwell-Chern-Simons-Higgs Mechanical Model

We apply different integrability analysis procedures to a reduced (spatially homogeneous) mechanical system derived from an off-shell non-minimally coupled N=2 Maxwell-Chern-Simons-Higgs model that presents BPS topological vortex excitations, numerically obtained with an ansatz adopted in a special - critical coupling - parametric regime. As a counterpart of the regularity associated to the static soliton-like solution, we investigate the possibility of chaotic dynamics in the evolution of the spatially homogeneous reduced system, descendant from the full N=2 model under consideration. The originally rich content of symmetries and interactions, N=2 susy and non-minimal coupling, singles out the proposed model as an interesting framework for the investigation of the role played by (super-)symmetries and parametric domains in the triggering/control of chaotic behavior in gauge systems. After writing down effective Lagrangian and Hamiltonian functions, and establishing the corresponding canonical Hamilton equations, we apply global integrability Noether point symmetries and Painleveproperty criteria to both the general and the critical coupling regimes. As a non-integrable character is detected by the pair of analytical criteria applied, we perform suitable numerical simulations, as we seek for chaotic patterns in the system evolution. Finally, we present some Comments on the results and perspectives for further investigations and forthcoming communications.

hep-th↗

Remarks on the Causality, Unitarity and Supersymmetric Extension of the Lorentz and CPT-Violating Maxwell-Chern-Simons Model

The gauge-invariant Chern-Simons-type Lorentz- and CPT-breaking term is here re-assessed and issues like causality, unitarity, spontaneous gauge-symmetry breaking are investigated. Moreover, we obtain a minimal extension of such a system to a supersymmetric environment. We comment on resulting peculiar self-couplings for the gauge sector, as well as on background contribution for gaugino masses.

hep-th↗

Supersymmetric Extension of the Lorentz and CPT-Violating Maxwell-Chern-Simons Model

Focusing on gauge degrees of freedom specified by a 1+3 dimensions model hosting a Maxwell term plus a Lorentz and CPT non-invariant Chern-Simons-like contribution, we obtain a minimal extension of such a system to a supersymmetric environment. We comment on resulting peculiar self-couplings for the gauge sector, as well as on background contribution for gaugino masses. Furthermore, a non-polynomial generalization is presented.

hep-th↗

An Extended Abelian Chern-Simons Model and the Symplectic Projector Method

The Symplectic Projector Method is applied to discuss quantisation aspects of an extended Abelian model with a pair of gauge potentials coupled by means of a mixed Chern-Simons term. We focuss on a field content that spans an N=2-D=3 supersymmetric theory whenever scalar and fermionic matter is suitably coupled to the family of gauge potentials.

hep-th↗

N=2-Maxwell-Chern-Simons model with anomalous magnetic moment coupling via dimensional reduction

An N=1--supersymmetric version of the Cremmer-Scherk-Kalb-Ramond model with non-minimal coupling to matter is built up both in terms of superfields and in a component-field formalism. By adopting a dimensional reduction procedure, the N=2--D=3 counterpart of the model comes out, with two main features: a genuine (diagonal) Chern-Simons term and an anomalous magnetic moment coupling between matter and the gauge potential.

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