arXiv subjects

Ernesto A. Matute

Publications and source records attributed to Ernesto A. Matute.

16 recordsLinked to original sources

arXiv2024

Dark sterile neutrinos on a linear seesaw of neutrino masses

Sterile neutrinos as source of mass and flavor mixing of active neutrinos as well as genesis of dark matter (DM) and matter-antimatter asymmetry have gained special interest. Here we study the case of the Standard Model (SM) extended with three right-handed (RH) neutrinos and a dark sector with two extra sterile neutrinos, odd under a discrete $Z_2$ symmetry. The RH neutrinos are responsible for producing baryon asymmetry via high-scale unflavored leptogenesis. They are superheavy and their abundance at the electroweak broken stage is vanishingly small, so that they have no impact on phenomenology at low energies. The two dark neutrinos generate the tiny mass of two active neutrinos through a mechanism similar to the minimal linear seesaw, and saturate the relic abundance as freeze-in DM coming mainly from decays of SM weak-gauge bosons via active-dark neutrino mixing. The absence of the dark Majorana mass terms in the dark linear seesaw is explained by invoking a hidden symmetry, the so-called presymmetry, and the DM candidate appears in the form of a quasi-Dirac neutrino. The $Z_2$ symmetry is broken in the dark neutrino sector, but exact in the realm of RH neutrinos. The required coupling weakness for the freeze-in DM neutrino is related to a very small breach of the unitarity of the active neutrino mixing matrix. We show how phenomenological constraints on the production and decay of the DM neutrino imply an upper bound around 1 MeV for its mass and unitarity up to $\mathcal{O}(10^{-7})$ for the mixing matrix.

hep-ph↗

arXiv2022

Neutrino flavor mixing with approximate $μ$-$τ$ symmetry within the low-scale minimal linear seesaw model

Neutrino flavor mixing is explained within the recently proposed low-scale minimal linear seesaw model of neutrino mass generation, a variant of the standard linear seesaw led by a Dirac pair of extra sterile neutrinos which is odd under a discrete $Z_2$ symmetry and has a mass at or below the GeV scale. The tri-bimaximal mixing and its deviations are derived straightforwardly on the basis of the symmetry between $μ$ and $τ$ flavors, without introducing non-abelian discrete flavor symmetries in the first place.

hep-ph↗

arXiv2021

Low-scale minimal linear seesaw model for neutrino mass and flavor mixing

We consider an extension of the Standard Model with three right-handed (RH) neutrinos and a Dirac pair of extra sterile neutrinos, odd under a discrete $Z_2$ symmetry, in order to have left-right symmetry in the neutrino content and obtain tiny neutrino masses from the latter ones only. Our working hypothesis is that the heavy RH neutrinos do not influence phenomenology at low energies. We use the usual high-scale seesaw to suppress all of the mass terms involving RH neutrinos and a low-scale minimal variant of the linear seesaw led by the Dirac mass of the extra sterile neutrinos to provide the small mass of active neutrinos. One of the active neutrinos is massless, which fixes the mass of the other two on the basis of a soft breaking of the $Z_2$ symmetry. The mixing between the extra neutrinos makes for a particle that effectively behaves like a Dirac sterile neutrino with mass around the GeV level.

hep-ph↗

arXiv2019

Neutrino mass generation from the perspective of presymmetry

The Standard Model (SM) with one right-handed neutrino per generation is revisited with presymmetry being the global $U(1)_{B-L}$ symmetry of an electroweak theory of leptons and quarks with initially postulated symmetric fractional charges. The cancellation of gauge anomalies and the non-perturbative normalization of lepton charges proceed through the mixing of local and topological charges, the global $B-L$ measuring the induced charge associated with a unit of topological charge, and the mathematical replacement of the original fractional charges with the experimentally observed ones. The $U(1)_{B-L}$ symmetry of the SM with Dirac neutrinos is seen as a residual presymmetry. High-scale and low-scale seesaw mechanisms proposed to explain the mass of neutrinos are examined from the perspective of presymmetry, be they of Majorana or pseudo-Dirac type. We find that the tiny mass splitting in pseudo-Dirac neutrinos and the mass of heavy neutrinos ride on the opposite ends of the seesaw. We show that pseudo-Dirac neutrinos contain extra sterile neutrinos with imprints of presymmetry and for heavy ones we get constraints favoring the low-scale linear seesaw over the inverse variant.

hep-ph↗

arXiv2015

Presymmetry in the Standard Model with adulterated Dirac neutrinos

Recently we proposed a model for light Dirac neutrinos in which two right-handed (RH) neutrinos per generation are added to the particles of the Standard Model (SM), implemented with the symmetry of fermionic contents. The ordinary one is decoupled via the high scale type-I seesaw mechanism, while the extra pairs off with its left-handed (LH) partner. The symmetry of lepton and quark contents was merely used as a guideline to the choice of parameters because it is not a proper symmetry. Here we argue that the underlying symmetry to take for this correspondence is presymmetry, the hidden electroweak symmetry of the SM extended with RH neutrinos defined by transformations which exchange lepton and quark bare states with the same electroweak charges and no Majorana mass terms in the underlying Lagrangian. It gives a topological character to fractional charges, relates the number of families to the number of quark colors, and now guarantees the great disparity between the couplings of the two RH neutrinos. Thus, Dirac neutrinos with extremely small masses appear as natural predictions of presymmetry, satisfying the 't Hooft's naturalness conditions in the extended seesaw where the extra RH neutrinos serve to adulterate the mass properties in the low scale effective theory, which retains without extensions the gauge and Higgs sectors of the SM. However, the high energy threshold for the seesaw implies new physics to stabilize the quantum corrections to the Higgs boson mass in agreement with the naturalness requirement.

hep-ph↗

arXiv2015

Neutrino mass generation with extra right-handed fields in a Dirac scenario via the type-I seesaw mechanism

An extension of the Standard Model (SM) is studied in which two right-handed (RH) neutrinos per generation are incorporated, but considering the hypothesis of the symmetry of lepton and quark contents in order to deprive the number of RH neutrinos of freedom, generate Dirac neutrinos and accommodate naturally tiny values for their masses. The high scale type-I seesaw regime is applied to the first, ordinary RH neutrino, whereas a low scale pseudo-Dirac scenario is used for the second, adulterant RH neutrino, implying that the first RH neutrino decouples at the high scale, while the second RH neutrino survives down to the low scale to pair off in a Dirac-like form with the corresponding left-handed (LH) neutrino. The small mass and couplings of this extra RH neutrino are explained by means of the statement of the symmetry of fermionic content, only regarded as a guideline to the natural choice of parameters since it is not a proper symmetry in the Lagrangian.

hep-ph↗

arXiv2011

Restoration of Parity Symmetry through Presymmetry

Presymmetry, the hidden symmetry underlying the charge and generational patterns of quarks and leptons, is utilized for repairing the left-right asymmetry of the standard model with Dirac neutrinos. It is shown that the restoration of parity is consequent with an indispensable left-right symmetric residual presymmetry. Thus, presymmetry substantiates left-right symmetry and the experimental search for the latter is the test of the former, with the nature of neutrinos as a crucial feature that can distinguish the left-right symmetry alone and its combination with presymmetry. This phenomenological implication is in accordance with the fact that Majorana neutrinos are usually demanded in the first case, but forbidden in the second.

hep-ph↗

arXiv2011

Twin and Mirror Symmetries from Presymmetry

We argue that presymmetry, a hidden predynamical electroweak quark-lepton symmetry that explains the fractional charges and triplication of families, must be extended beyond the Standard Model as to have a residual presymmetry that embraces partner particles and includes the strong sector, so accounting for the twin or mirror partners proposed to alleviate the naturalness problem of the weak scale. It leads to the full duplication of fermions and gauge bosons of the Standard Model independently of the ultraviolet completion of the theory, even if the Higgs particle is discarded by experiment, which adds robustness to twin and mirror symmetries. The established connection is so strongly motivated that the search for twin or mirror matter becomes the possible test of presymmetry. If the physics beyond the Standard Model repairs its left-right asymmetry, mirror symmetry should be the one realized in nature.

hep-ph↗

arXiv2010

Presymmetry Beyond the Standard Model

We go beyond the Standard Model guided by presymmetry, the discrete electroweak quark-lepton symmetry hidden by topological effects which explain quark fractional charges as in condensed matter physics. We show that partners of the particles of the Standard Model and the discrete symmetry associated with this partnership appear as manifestations of a residual presymmetry in the sense of Ekstein and its extension from matter to forces. This duplication of the spectrum of the Standard Model keeps spin and comes nondegenerated about the TeV scale.

hep-ph↗

arXiv2009

Presymmetry beyond the Standard Model

We go beyond the Standard Model guided by presymmetry, the discrete electroweak quark-lepton symmetry hidden by topological effects which explain quark fractional charges as in condense matter physics. Partners of the particles of the Standard Model and the discrete symmetry associated with this partnership appear as manifestations of a residual presymmetry and its extension from matter to forces. This duplication of the spectrum of the Standard Model keeps spin and comes nondegenerated about the TeV scale.

hep-ph↗

arXiv2007

Electroweak quark-lepton symmetry and weak topological-charge confinement in the Standard Model with Dirac neutrinos

The standard electroweak model with Dirac neutrinos is extended by way of the principles of electroweak quark-lepton symmetry and weak topological-charge confinement to account for quark-lepton charge relations which, if not accidental, are indicative of charge structures. A mixing in quarks and leptons of underlying integer local charges with integer weak topological charges associated with an additive group Z_3, fixed by the anomaly cancellation requirement, is discussed. It is found that the electroweak difference between topological quarks and leptons is the nonequivalence between the topological vacua of their weak field configurations, produced by a four-instanton which carries the topological charge, induces the universal fractional piece of charge distinguishing quarks from leptons, and breaks the underlying symmetry. The constituent quarks of the standard model appear as coming from topological quarks, via the weak four-instanton event. Dual transitions occur for leptons. It is shown that several other fundamental problems left open in the standard electroweak model with Dirac neutrinos are solved: the one-to-one correspondence between quark and lepton flavors, the existence of three generations, the conservation and ungauging of B-L, the electric charge quantization, and the confinement of fractional electric charges.

hep-ph↗

arXiv2006

Unification of standard and exotic matter through a $Z_2$ symmetry

We consider a scenario in which the discrete weak symmetry between quarks and leptons is extended to the weak force by introducing exotic partners. We conjecture that there exists a hidden discrete symmetry $\tilde{P}$, defining a $Z_2$ group, between standard and exotic quarks and leptons. The unified model $SU(3)_{q} \times SU(3)_{\tilde{q}} \times SU(2)_{q \tilde{\ell}} \times SU(2)_{\tilde{q} \ell} \times U(1)_{Y} \times \tilde{P}$ is discussed, where the unifying discrete symmetry extends over particles and forces. It is shown that the lighter neutral and charged weak bosons generated upon spontaneous symmetry breaking have the same properties as those of the standard model. Cabbibo-Kobayashi-Maskawa unitarity is used to set a mass of order 2.8 TeV for the nonstandard weak bosons, which do not exhibit quark-lepton universality. A grand unified theory of $GUT_{q \tilde{\ell}} \times GUT_{\tilde{q} \ell} \times \tilde{P}$ type, with decay of exotic matter into standard matter and no decay of the ordinary nucleon, is put forward.

hep-ph↗

arXiv2004

Transverse Solutions of the Vector Laplace and Helmholtz Equations for Spherical Coordinates and Boundary Conditions with Azimuthal Symmetry

A scalar field method to obtain transverse solutions of the vector Laplace and Helmholtz equations in spherical coordinates for boundary-value problems with azimuthal symmetry is described. Neither scalar nor vector potentials are used. Solutions are obtained by use of separation of variables instead of dyadic Green's functions expanded in terms of vector spherical harmonics. Applications to the calculations of magnetic fields from steady and oscillating localized current distributions are presented.

physics.class-ph↗

arXiv2004

Topological Charges, Prequarks and Presymmetry: a Topological Approach to Quark Fractional Charges

A topological approach to quark fractional charges, based on charge constraints unexplained by the Standard Model of particle physics, is discussed. Charge fractionalization is related to a tunneling process occurring in time between pure gauge field configurations at the far past and future associated with integer-charged bare quarks, named prequarks. This transition conforms to a topologically nontrivial configuration of the weak gauge fields in Euclidean space-time. In this context, an electroweak $Z_{2}$ symmetry between bare quarks and leptons, named presymmetry, is revealed. It is shown that an effective topological charge equal to the ratio between baryon number and the number of fermion generations may be associated with baryonic matter. The observed conservation of baryon number is then connected with the conservation of this charge on quarks. Similar results are obtained for leptons in the dual scenario with local quark charges.

hep-ph↗

arXiv2004

A topological view on baryon number conservation

We argue that the charge fractionalization in quarks has a hidden topological character related to a broken ${\cal Z}_2$ symmetry between integer-charged bare quarks and leptons. The mechanism is a tunneling process occurring in time between standard field configurations of a pure gauge form with different topological winding numbers associated with integer-charged bare quarks in the far past and future. This transition, which nonperturbatively normalizes local bare charges with a universal accumulated value, corresponds to a specific topologically nontrivial configuration of the weak gauge fields in Euclidean spacetime. The outcome is an effective topological charge equal to the ratio between baryon number and the number of fermion generations associated with baryonic matter. The observed conservation of baryon number is then related to the conservation of this bookkeeping charge on quarks. Baryon number violation may only arise through topological effects as in decays induced by electroweak instantons. However, stability of a free proton is expected.

hep-ph↗

arXiv2002

Chern-Simons-fermion model of quarks

We propose an extension of the standard model where quarks are viewed as fermions with a ``bare'' integer (weak) hypercharge which is normalized with a fractional part created by a quantized topological Chern-Simons configuration of the weak gauge fields. Consistency with hypercharge patterns not included in the standard model is shown.

hep-ph↗