arXiv subjects

Maximiliano A. Rivera

Publications and source records attributed to Maximiliano A. Rivera.

9 recordsLinked to original sources

arXiv2026

Radiative neutrino mass generation and dark matter through vectorlike leptons

This study presents a radiative three-loop model for neutrino mass generation, employing an asymmetric Yukawa coupling between two new scalar $SU(2)_L$ doublets and vectorlike lepton doublets. Dark matter candidates arise from one of the scalar doublets and contribute to neutrino mass generation through the mass splitting between its neutral components. The singly charged scalars are also essential for neutrino mass, with the charged states of the two doublets mixing with one another. A single generation of vectorlike leptons yields two nonzero neutrino masses as a consequence of the asymmetric Yukawa combinations entering the neutrino mass matrix. The model is tested against dark matter phenomenology, neutrino mass and mixing data, and the charged lepton flavor-violating process $μ\rightarrow e γ$, showing compatibility with current bounds and leading to experimentally accessible predictions.

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arXiv2020

Lepton number violating operators with standard model gauge fields: A survey of neutrino masses from 3-loops and their link to dark matter

We investigate neutrino mass generation scenarios where the lepton number breaking new physics couples only to the Standard Model (SM) right-handed charged lepton chirality. The lowest-order lepton number violating effective operator which describes this framework is a unique dimension nine operator involving SM gauge fields, $\mathcal{O}_9$. We find that there are two possible classes of new physics scenarios giving rise to this $\mathcal{O}_9$ operator. In these scenarios neutrino masses are induced radiatively via dark matter interactions, linking the dark matter to a natural explanation for the smallness of neutrino masses compared to the electroweak scale. We discuss the phenomenology and existing constraints in the different neutrino mass models within each class. In particular, we analyze the important interplay between neutrino mixing and neutrinoless double $β$-decay in order to predict characteristic signatures and disfavour certain scenarios.

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arXiv2014

On Neutrino Masses in the MSSM with BRpV

One loop corrections to the neutrino mass matrix within the MSSM with Bilinear R Parity Violation are calculated, paying attention to the approach in which an effective $3\times 3$ neutrino mass matrix is used. The full mass matrix is block diagonalized, it is found that second and third order terms can be numerically important, and this is analytically understood. Top-stop loops do not contribute to the effective $3\times 3$ at first order, nevertheless they contribute at third. An improved $3\times 3$ approach that include these effects is proposed.

hep-ph↗

arXiv2014

Radiative neutrino mass generation linked to neutrino mixing and $0νββ$-decay predictions

We discuss the connection between the origin of neutrino masses and their mixings which arises in a class of scenarios with radiatively induced neutrino masses. In these scenarios, the neutrino mass matrix acquires textures with two entries close to zero in the basis where the charged-lepton mass matrix is diagonal. This results in specific constraints on the neutrino mixing parameters, which leads to the prediction of (i) a normal ordering of neutrino masses with the lightest neutrino mass in the $\sim$ meV range and (ii) testable correlations among the various mixing angles, including a nonzero $θ_{13}$ angle with its exact value correlated with the values of the atmospheric angle $θ_{23}$ and the $CP$ phase $δ$. We quantify the impact of deviations from exact zeroes in the mass matrix texture and connect it to the amount of hierarchy among Yukawa couplings. These scenarios of radiative neutrino mass generation also give rise to new short-range contributions to neutrinoless double beta decay, which dominate over the usual light-neutrino exchange contribution. As a result, this class of models can have a sizable neutrinoless double beta decay rate, in the range of upcoming experiments despite the normal mass ordering of neutrinos.

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arXiv2014

Predictive Model for Radiatively Induced Neutrino Masses and Mixings with Dark Matter

A minimal extension of the standard model to naturally generate small neutrino masses and provide a dark matter candidate is proposed. The dark matter particle is part of a new scalar doublet field that plays a crucial role in radiatively generating neutrino masses. The symmetry that stabilizes the dark matter also suppresses neutrino masses to appear first at three-loop level. Without the need of right-handed neutrinos or other very heavy new fields, this offers an attractive explanation of the hierarchy between the electroweak and neutrino mass scales. The model has distinct verifiable predictions for the neutrino masses, flavor mixing angles, colliders and dark matter signals.

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arXiv2010

Fermiophobia in a Higgs Triplet Model

A Fermiophobic Higgs boson can arise in models with an extended Higgs sector, such as models with scalars in an isospin triplet representation. In a specific model with a scalar triplet and spontaneous violation of lepton number induced by a scalar singlet field, we show that fermiophobia is not a fine-tuned situation, unlike in Two Higgs Doublet Models. We study distinctive signals of fermiophobia which can be probed at the LHC. For the case of a small Higgs mass a characteristic signal would be a moderate B(H ->γγ) accompanied by a large B(H -> JJ) (where J is a Majoron), the latter being an invisible decay. For the case of a large Higgs mass there is the possibility of dominant H -> ZZ, WW and suppressed H -> JJ decay modes. In this situation, B(H -> ZZ) is larger than B(H -> WW), which differs from the SM prediction.

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arXiv2009

NLO Polarized Chargino pair Production in Electron Positron Annihilation

We calculate the complete one-loop quantum corrections to the helicity eigenstate chargino pair production cross sections in polarized electron positron collisions, within the Minimal Supersymmetric Standard Model. We calculate the non-QED corrections using the helicity amplitudes formalism, and Dimensional Regularization to deal with ultraviolet divergences. We calculate QED corrections using the dipole subtraction formalism to extract soft and collinear divergences in Bremsstrahlung, canceling them with the infrared divergences from virtual QED corrections. We show numerical results for the Focus Point scenario in mSUGRA, where we find important quantum corrections for differential cross sections with definite chargino helicities.

hep-ph↗

arXiv2007

Effect of Charged Scalar Loops on Photonic Decays of a Fermiophobic Higgs

Higgs bosons with very suppressed couplings to fermions ("Fermiophobic Higgs bosons", h_f) can decay to two photons (γγ) with a branching ratio significantly larger than that expected for the Standard Model Higgs boson for m_{h_f}<150 GeV. Such a particle would give a clear signal at the LHC and can arise in the Two Higgs Doublet Model (type I) in which h_f -> γγis mediated by W^+ and charged Higgs boson (H^+) loops. We show that the H^+ loops can cause both constructive and destructive contributions with a magnitude considerably larger than the anticipated precision in the measurement of the photonic decay channel at future hadron and lepton colliders.

hep-ph↗

arXiv2002

Neutrino Physics from Charged Higgs and Slepton Associated Production in AMSB

In the Minimal Supersymmetric Standard Model with bilinear R-Parity violation, terms that violate R-Parity and lepton number are introduced in the superpotential, and sneutrino vacuum expectation values are induced. As a result, neutrino masses and mixing angles are generated via a low energy see-saw mechanism. We show that this model embedded into an anomaly mediated supersymmetry breaking scenario is testable at a linear collider using charged Higgs boson production in association with a stau. This is possible in regions of parameter space where the charged Higgs and stau have similar mass, producing an enhancement of the charged scalar mixing angles. We show that the bilinear parameter and the sneutrino vev can be determined from charged scalar observables, and estimate the precision of this determination.

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