An Engineering Approach towards Action Refinement

In the abstract modelling of distributed systems we may need methods to replace abstract behaviours by more concrete behaviours which are closer to implementation mechanisms. Furthermore, we may want these methods to preserve the correctness of such a replacement. This paper introduces an approach towards action refinement in which an abstract action is replaced by a concrete activity. This approach is based on a careful consideration of the `action' and `causality relation' architectural concepts, which enable an abstract action to be replaced by many alternative concrete activities in a general way. This approach is based on the application of abstraction rules to determine whether a concrete activity conforms to an abstract action, considering the context in which the concrete activity and the abstract action are embedde

The seesaw mechanism at TeV scale in the 3-3-1 model with right-handed neutrinos

We implement the seesaw mechanism in the 3-3-1 model with right-handed neutrinos. This is accomplished by the introduction of a scalar sextet into the model and the spontaneous violation of the lepton number. We identify the Majoron as a singlet under $SU_L(2)\otimes U_Y(1)$ symmetry, which makes it safe under the current bounds imposed by electroweak data. The main result of this work is that the seesaw mechanism works already at TeV scale with the outcome that the right-handed neutrino masses lie in the electroweak scale, in the range from MeV to tens of GeV. This window provides a great opportunity to test their appearance at current detectors, though when we contrast our results with some previous analysis concerning detection sensitivity at LHC, we conclude that further work is needed in order to validate this search.Comment: about 13 pages, no figure

Novel sources of Flavor Changed Neutral Currents in the 331RHN331_{RHN} model

Sources of Flavor Changed Neutral Currents (FCNC) naturally emerge from a well motivated framework called 3-3-1 with right-handed neutrinos model, $331_{RHN}$ for short, mediated by an extra neutral gauge boson $Z^{\prime}$. Following previous works we calculate these sources and in addition we derive new ones coming from CP-even and -odd neutral scalars which appear due to their non-diagonal interactions with the physical standard quarks. Furthermore we show that bounds related to the neutral mesons systems $K_L-K_S$ and $D_1^0 - D_2^0$ may be significantly strengthened in the presence of these new interactions allowing us to infer stronger constraints on the parameter space of the model.Comment: Published version. 10 pages, 6 figure

Dynamically Induced Spontaneous Symmetry Breaking in 3-3-1 Models

We show that in SU(3)_C X SU(3)_L X U(1)_N (3-3-1) models embedded with a singlet scalar playing the role of the axion, after imposing scale invariance, dynamical symmetry breaking of Peccei-Quinn symmetry occurs through the one-loop effective potential for the singlet field. We, then, analyze the structure of spontaneous symmetry breaking by studying the new scalar potential for the model, and verify that electroweak symmetry breaking is tightly connected to the 3-3-1 breaking by the strong constraints among their vacuum expectation values. This offers a valuable guide to write down the correct pattern of symmetry breaking for multi-scalar theories. We also obtained that the accompanying massive pseudo-scalar, instead of acquiring mass of order of Peccei-Quinn scale as we would expect, develops a mass at a much lower scale, a consequence solely of the dynamical breaking.Comment: 12 pages, typos corrected, improved text, conclusions unchange

Electric charge quantization and the muon anomalous magnetic moment

We investigate some proposals to solve the electric charge quantization puzzle, which simultaneously explain the recent measured deviation on the muon anomalous magnetic moment. For this we assess extensions of the Electro-Weak Standard Model spanning modifications on the scalar sector only. It is interesting to verify that one can have modest extensions which easily account for the solution for both problems.Comment: 20 pages, 1 figures, needs macro axodraw.st

Right circumcaval ureter and double right renal vein in the Brazilian shorthair cat (Felis catus): two case reports

Variations of the renal veins are well described in the literature, although variations concerning the ureter are considered a rare finding in cats. The circumcaval ureter is one of the rarest variations of the ureter and is characterised by a loop of the ureter posterior to the caudal vena cava. This variant is also known as preureteral vena cava and retrocaval ureter. It is thought to be caused by a deviation during embryonic development of the aforementioned vein. Due to its rarity, there are scarce reports of the circumcaval ureter in cats, and its association with two renal veins makes it less common as well. These variations should be preoperatively identified in order to avoid complications in kidney transplants, ureteral surgeries and cystoscopies, for instance. The present work aims to report two cases of a circumcaval ureter with two renal veins in two different Brazilian shorthair cats (Felis catus)

Naturally light right-handed neutrinos in a 3-3-1 Model

In this work we show that light right-handed neutrinos, with mass in the sub-eV scale, is a natural outcome in a 3-3-1 model. By considering effective dimension five operators, the model predicts three light right-handed neutrinos, weakly mixed with the left-handed ones. We show also that the model is able to explain the LSND experiment and still be in agreement with solar and atmospheric data for neutrino oscillation.Comment: About 5 pages, no-figure

MiniBooNE Results and Neutrino Schemes with 2 sterile Neutrinos: Possible Mass Orderings and Observables related to Neutrino Masses

The MiniBooNE and LSND experiments are compatible with each other when two sterile neutrinos are added to the three active ones. In this case there are eight possible mass orderings. In two of them both sterile neutrinos are heavier than the three active ones. In the next two scenarios both sterile neutrinos are lighter than the three active ones. The remaining four scenarios have one sterile neutrino heavier and another lighter than the three active ones. We analyze all scenarios with respect to their predictions for mass-related observables. These are the sum of neutrino masses as constrained by cosmological observations, the kinematic mass parameter as measurable in the KATRIN experiment, and the effective mass governing neutrinoless double beta decay. It is investigated how these non-oscillation probes can distinguish between the eight scenarios. Six of the eight possible mass orderings predict positive signals in the KATRIN and future neutrinoless double beta decay experiments. We also remark on scenarios with three sterile neutrinos. In addition we make some comments on the possibility of using decays of high energy astrophysical neutrinos to discriminate between the mass orderings in presence of two sterile neutrinos.Comment: 33 pages, 8 figures. Comments added, to appear in JHE

Dead or alive? Implications of the muon anomalous magnetic moment for 3-3-1 models

Indexación: Scopus.We have witnessed a persistent puzzling anomaly in the muon magnetic moment that cannot be accounted for in the Standard Model even considering the existing large hadronic uncertainties. A new measurement is forthcoming, and it might give rise to a 5σ claim for physics beyond the Standard Model. Motivated by it, we explore the implications of this new result to five models based on the SU(3)C×SU(3)L×U(1)N gauge symmetry and put our conclusions into perspective with LHC bounds. We show that previous conclusions found in the context of such models change if there are more than one heavy particle running in the loop. Moreover, having in mind the projected precision aimed by the g-2 experiment at FERMILAB, we place lower mass bounds on the particles that contribute to muon anomalous magnetic moment assuming the anomaly is otherwise resolved. Lastly, we discuss how these models could accommodate such anomaly in agreement with current bounds. © 2020 The Author(s) Learn about these Topicshttps://www-sciencedirect-com.recursosbiblioteca.unab.cl/science/article/pii/S0370269320304925?via%3Dihu