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M. A. De Andrade

Publications and source records attributed to M. A. De Andrade.

At least 19 recordsLinked to original sources
arXiv2026

Massive Dirac neutrinos from an alternative extension of the Standard Model

An alternative approach for deriving neutrino masses from the known masses of quarks, charged leptons, and the parameters of the Pontecorvo--Maki--Nakagawa--Sakata (PMNS) matrix is proposed. This framework is based on the simultaneous diagonalization of the kinetic and mass terms in an extension of the Standard Model (SM) with massive Dirac neutrinos, which have four degrees of freedom ($ν_L$, $ν_R$, and their antiparticles). Consistent with experimental data, numerical results for the neutrino masses are obtained through a calibration procedure that predicts the value of the CP phase $\dcp$, thereby reducing the number of independent flavor parameters in this SM extension. A scale parameter $\anu$ is introduced to adjust the mass splittings $Δm^2_{21}$ and $Δm^2_{31}$ to match their precise experimental values. The proposed framework connects neutrino mass generation to the known masses of quarks and charged leptons, offering a unified perspective on the matter sector of the SM.

hep-ph↗
arXiv2023

Noncommutative Derivation of the Planck's Radiation Law

The Planck's radiation law for the blackbody radiation spectrum was capable to explain the experimentally-measured blackbody spectrum. In order to get this result, Planck proposed his radiation law in a two-fold way: 1) by an \textit{ad hoc} modification of the assumed connection between energy and entropy for thermal radiation; 2) by assuming that the calculation of the entropy of an oscillator in thermal equilibrium with radiation is carried out by discrete units of energy. As a consequence, the energy quantization, linear in frequency, was thus introduced into physics. However, the energy quantization of the simple harmonic oscillator was originally postulated by Planck in an incomplete way, i.e., the ground state energy was not assumed to be null. Of course, this issue has been solved in different ways over time. Despite of this, we propose an alternative way to fix this issue by describing harmonic oscillators at noncommutative(NC) framework, where the non-null ground state energy naturally arises as a NC contribution. With this approach, the Planck's quantum theory is updated and, consequently, becomes compatible with the quantum mechanics inaugurated in 1925.

quant-ph↗
arXiv2021

Noncommutative approach to diagnose degenerate Higgs bosons at 125 GeV

We propose a noncommutative (NC) version for a global O(2) scalar field theory, whose damping feature is introduced into the scalar field theory through the NC parameter. In this context, we investigate how noncommutative drives spontaneous symmetry breaking (SSB) and Higgs-Kibble mechanisms and how the damping feature workout. Indeed, we show that the noncommutativity plays an important role in such mechanisms, i.e., the Higgs mass and VEV dependent on NC parameter. After that, it is explored the consequences of noncommutativity dependence of Higgs mass and VEV: for the first, it is shown that there are a mass-degenerate Higgs bosons near 126.5 GeV, parametrized by the noncommutativity; for the second, the gauge fields gain masses that present a noncommutativity contribution.

hep-ph↗
arXiv2019

Noncommutative approach to disclose a Higgs group

A noncommutative(NC) version for a global $O(N)$ scalar field theory is proposed and an alternative investigation about how noncommutative drives spontaneous symmetry breaking (SSB) is explored. Indeed, we show that the noncommutativity plays an important role in such mechanism, i.e., it is possible to show that there is a Higgs group with no more than two Higgs bosons. In this scenario, we establish two mutually exclusive options: one Higgs boson with mass at 125 GeV and other at 750 GeV -- 2 TeV excess does not imply a 2 TeV mass resonance -- or two Higgs bosons with mass-degenerate near 125~GeV, where 2 TeV and 750 GeV excesses do not imply a 2 TeV and 750 GeV masses resonance.

hep-ph↗
arXiv2018

Noncommutative Mapping from the symplectic formalism

The Bopp's shifts will be generalized through symplectic formalism. A special procedure, like a "diagonalization", which drives the completely deformed symplectic matrix to the standard symplectic form was found as suggested by Faddeev-Jackiw. Consequently, the correspondent transformation matrix guides the mapping from commutative to noncommutative (NC) phase-space coordinates. The Bopp's shifts may be directly generalized from this mapping. In this context, all the NC and scale parameters, introduced into the brackets, will be lifted to the Hamiltonian. Well known results, obtained using $\star$-product, will be reproduced without to consider that the NC parameters are small$(<<1)$. Besides, it will be shown that different choices for NC algebra among the symplectic variables generates distinct dynamical systems, which they may not even connect with each other, and that some of them can preserve, break or restore the symmetry of the system. Further, we will also discuss the charge and mass rescaling in a simple model.

hep-th↗
arXiv2015

An alternative way to explain how non-commutativity arises in the bosonic string theory

In this work we will investigate how the non-commutativity arises into the string theory, \textit{i.e.}, how the bosonic string theory attaches to a D3-brane in the presence of magnetic fields. In order to accomplish the proposal, we departure from the commutative two-dimensional harmonic oscillator, which after the application of the general Bopp's shifts Matrix Method, the non-commutative version of the two-dimensional harmonic oscillator is obtained. After that, this non-commutative harmonic oscillator will be mapped into the bosonic string theory in the light cone frame, which it now appears as a bosonic string theory attached to a D3-brane.

hep-th↗
arXiv2011

Mass Generation and Related Issues from Exotic Higher Dimensions

The main purpose of this work is to show that massless Dirac equation formulated for non-interacting Majorana-Weyl spinors in higher dimensions, particularly in D=1+9 and D=5+5, can lead to an interpretation of massive Majorana and Dirac spinors in D=1+3. By adopting suitable representations of the Dirac matrices in higher dimensions, we pursue the investigation of which higher dimensional space-times and which mass-shell relation concerning massless Dirac equations in higher dimensions may induce massive spinors in D=1+3. The mixing of the chiral fermions in higher dimensions may induce a mechanism such that four massive Majorana fermions may show up and, at an appropriate limit an almost zero and a huge mass show up with corresponding left-handed and right-handed eigenstates. This mechanism, in a peculiar way, could reassess the See-Saw scheme associated to neutrino with Majorana-type masses. Remarkably the masses of the particles are fixed by the dimension decoupling/reduction scheme based on the mass Lorentz invariant term, where one set of the decoupled dimensions are the "target" coordinates frame and the other set of coordinates is the composing block of the mass term in lower dimensions. This proposal should allow us to understand the generation of hierarchies, such as the fourth generation, for the fermionic masses in D=1+3, or in lower dimensions in general, starting from the constraints between the energy and the momentum in D=n+n. For the initial D=5+5 Majorana-Weyl spinors framework using the Weyl representation to the Dirac matrices we observe an intriguing decomposition of space-time that result in two very equivalent D=1+4 massive spinors which mass term, in D=1+3 included, is originated from the remained/decoupled component and that could induce a Brane-World mechanism.

hep-th↗
arXiv2005

Gauge Theories with Lorentz-Symmetry Violation by Symplectic Projector Method

The violation of Lorentz symmetry is studied from the point of view of a canonical formulation. We make the usual analysis on the constraints structure of the Carroll-Field-Jackiw model. In this context we derive the equations of motion for the physical variables and check out the dispersion relations obtained from them. Therefore, by the analysis using Symplectic Projector Method (SPM), we can check the results about this type of Lorentz breaking with those in the recent literature: in this sense we can confirm that the configuration of $v^μ$ space-like is stable, and the $v^μ$ time-like carry tachionic modes.

hep-th↗
arXiv2002

On The Symplectic Two-Form of Gravity in Terms of Dirac Eigenvalues

The Dirac eigenvalues form a subset of observables of the Euclidean gravity. The symplectic two-form in the covariant phase space could be expressed, in principle, in terms of the Dirac eigenvalues. We discuss the existence of the formal solution of the equations defining the components of the symplectic form in this framework.

gr-qc↗
arXiv2001

Local Physical Coodinates from Symplectic Projector Method

The basic arguments underlying the symplectic projector method are presented. By this method, local free coordinates on the constrait surface can be obtained for a broader class of constrained systems. Some interesting examples are analyzed.

hep-th↗
arXiv2001

Unconstrained Variables of Non-Commutative Open Strings

The boundary conditions of the bosonic string theory in non-zero $B$-field background are equivalent to the second class constraints of a discretized version of the theory. By projecting the original canonical coordinates onto the constraint surface we derive a set of coordinates of string that are unconstrained.These coordinates represent a natural framework for the quantization of the theory.

hep-th↗
arXiv2000

The Signature Triality of Majorana-Weyl Spacetimes

Higher dimensional Majorana-Weyl spacetimes present space-time dualities which are induced by the Spin(8) triality automorphisms. Different signature versions of theories such as 10-dimensional SYM's, superstrings, five-branes, F-theory, are shown to be interconnected via the S_3 permutation group. Bilinear and trilinear invariants under space-time triality are introduced and their possible relevance in building models possessing a space-versus-time exchange symmetry is discussed. Moreover the Cartan's ``vector/chiral spinor/antichiral spinor" triality of SO(8) and SO(4,4) is analyzed in detail and explicit formulas are produced in a Majorana-Weyl basis. This paper is the extended version of hep-th/9907148.

hep-th↗
arXiv2000

Duality of Coordinates and Matter Fields in Curved Spacetime

We show that there exists a duality between the local coordinates and the solutions of the Klein-Gordon equation in curved spacetime in the same sense as in the Minkowski spacetime. However, the duality in curved spacetime does not have the same generality as in flat spacetime and it holds only if the system satisfies certain constraints. We derive these constraints and the basic equations of duality and discuss the implications in the quantum theory.

gr-qc↗
arXiv1999

Superpropagators for explicitly broken 3D-supersymmetric theories

A systematic algorithm to derive superpropagators in the case of either explicitly or spontaneously broken supersymmetric three-dimensional theories is presented. We discuss how the explicit breaking terms that are introduced at tree-level induce 1-loop radiative corrections to the effective action. We also point out that the renormalisation effects and the breaking-inducing-breaking mechanism become more immediate whenever we adopt the shifted superpropagators discussed in this letter.

hep-th↗
arXiv1999

Triality of Majorana-Weyl Spacetimes With Different Signatures

Majorana-Weyl spacetimes offer a rich algebraic setup and new types of space-time dualities besides those discussed by Hull. The triality automorphisms of Spin(8) act non-trivially on Majorana-Weyl representations and Majorana-Weyl spacetimes with different signatures. In particular relations exist among the (1+9)-(5+5)-(9+1) spacetimes, as well as their transverse coordinates spacetimes (0+8)-(4+4)-(8+0). Larger dimensional spacetimes such as (2+10)-(6+6)-(10+2) also show dualities induced by triality. A precise three-languages dictionary is here given. It furnishes the exact translations among, e.g., the three different versions (one in each signature) of the ten-dimensional N=1 superstring and superYang-Mills theories. Their dualities close the six-element permutation group S_3. Bilinear and trilinear invariants allowing to formulate theories with a manifest space-time symmetry are constructed.

hep-th↗