scholarly journals NEUTRINO MIXING IN THE μνSSM

2013 ◽  
Vol 28 (24) ◽  
pp. 1350117 ◽  
Author(s):  
HAI-BIN ZHANG ◽  
TAI-FU FENG ◽  
LI-NA KOU ◽  
SHU-MIN ZHAO

Recently, several reactor oscillation experiments have successively measured a nonzero value for the neutrino mixing angle θ13, which is greater than five standard deviations. Within framework of the μ from ν Supersymmetric Standard Model (μνSSM), three tiny neutrino masses are generated at the tree level through TeV scale seesaw mechanism. In this work, we analyze the neutrino masses and mixing in the μνSSM with a "top-down" method, assuming neutrino mass spectrum with normal ordering or inverted ordering.

2015 ◽  
Vol 30 (26) ◽  
pp. 1530020 ◽  
Author(s):  
Ernest Ma ◽  
Rahul Srivastava

The gauged [Formula: see text] symmetry is one of the simplest and well-studied extension of Standard Model. In the conventional case, addition of three singlet right-handed neutrinos each transforming as [Formula: see text] under the [Formula: see text] symmetry renders it anomaly-free. It is usually assumed that the [Formula: see text] symmetry is spontaneously broken by a singlet scalar having two units of [Formula: see text] charge, resulting in a natural implementation of Majorana seesaw mechanism for neutrinos. However, as we discuss here, there is another simple anomaly-free solution which leads to Dirac or inverse seesaw masses for neutrinos. These new possibilities are explored along with an application to neutrino mixing with [Formula: see text] flavor symmetry.


2021 ◽  
Vol 36 (02) ◽  
pp. 2150010
Author(s):  
M. C. rodriguez

We build a supersymmetric model with [Formula: see text] gauge symmetry, with a global [Formula: see text] symmetry. The [Formula: see text] symmetry is necessary to keep the proton stable at least at tree level. There is also a global [Formula: see text] symmetry, where [Formula: see text] and [Formula: see text] are the usual baryonic and leptonic numbers, respectively. We introduce three nonidentical right-handed neutrinos plus new scalars fields. After symmetry breaking, the right-handed neutrinos together with one left-handed neutrino get Majorana masses via the seesaw mechanism. The other two left-handed neutrinos get their Majorana masses at 1-loop level. We will also explain the mixing angle in the neutrino sector in agreement with the experimental data and we get several interesting candidates to the observed dark matter.


2016 ◽  
Vol 26 (1) ◽  
pp. 1
Author(s):  
Phi Quang Van ◽  
Nguyen Thi Hong Van

Neutrino masses and mixing in an extended standard model acquiring an A4 flavour symmetry are considered. The corresponding three-neutrino mixing matrix obtained via a pertur- bative method allows us to determine the Dirac CP violation phase (\delta_{CP}) as a function of the mixing angles (\theta_{12}, \theta_{23}, \theta_{13}). Then, numerical values and distributions of \delta_{CP} are given. The latter values are quite close to the global fits of the experimental data for both the normal ordering and inverse ordering of the neutrino masses.


2009 ◽  
Vol 24 (32) ◽  
pp. 2589-2600 ◽  
Author(s):  
ADRIAN PALCU

In this paper we show that the canonical seesaw mechanism can naturally be implemented in a particular class of electroweak SU (4)L⊗ U (1)Ygauge models. The resulting neutrino mass spectrum is determined by just tuning a unique free parameter a within the algebraical method of treating gauge models with high symmetries proposed several years ago by Cotăescu. All the Standard Model phenomenology is preserved, being unaffected by the new physics occurring at a high breaking scale m ~ 1011GeV .


2012 ◽  
Vol 27 (28) ◽  
pp. 1250159 ◽  
Author(s):  
P. M. FERREIRA ◽  
L. LAVOURA

We suggest a simple model, based on the type-I seesaw mechanism, for the lepton mass matrices. The model hinges on an Abelian symmetry which leads to mass matrices with some vanishing matrix elements. The model predicts one massless neutrino and Meμ = 0 (M is the effective light-neutrino Majorana mass matrix). We show that these predictions agree with the present experimental data if the neutrino mass spectrum is inverted, i.e. if m3 = 0, provided the Dirac phase δ is very close to maximal (±π/ 2). In the case of a normal neutrino mass spectrum, i.e. when m1 = 0, the agreement of our model with the data is imperfect — the reactor mixing angle θ13 is too small in our model. Minimal leptogenesis is not an option in our model due to the vanishing elements in the Yukawa-coupling matrices.


2021 ◽  
Vol 81 (5) ◽  
Author(s):  
V. V. Vien

AbstractWe propose a non-renormalizable $$B-L$$ B - L model with $$S_{3}{\times Z_4\times Z_2}$$ S 3 × Z 4 × Z 2 symmetry which successfully accommodates the current active–sterile neutrino mixing in $$3+1$$ 3 + 1 scheme. The $$S_3$$ S 3 flavor symmetry is supplemented by $$Z_4\otimes Z_2$$ Z 4 ⊗ Z 2 symmetry to consolidate the Yukawa interaction of the model. The presence of $$S_3\otimes Z_4\otimes Z_2$$ S 3 ⊗ Z 4 ⊗ Z 2 flavour symmetry plays an important role in generating the desired structure of the neutrino mass matrix. The model can reproduce the recent observed active-neutrino neutrino oscillation data for normal ordering in which two sterile–active mixing angles $$\theta _{14, 24}$$ θ 14 , 24 get the best-fit values and the obtained values of $$\theta _{34}, \delta _{14}, \delta _{14}$$ θ 34 , δ 14 , δ 14 , the sum of neutrino mass and the effective neutrino masses are within their currently allowed ranges.


2020 ◽  
Vol 35 (22) ◽  
pp. 2050181
Author(s):  
V. V. Vien ◽  
D. P. Khoi

We propose a [Formula: see text] Standard Model (SM) extension based on [Formula: see text] symmetry in which neutrino mass orderings and the tiny neutrino masses are produced by the type-I seesaw mechanism. The obtained physical parameters are well consistent with the global fit of neutrino oscillation.1 The model is predictive in the sense that it reproduces the experimental values of neutrino parameters. Two of the predicted parameters have little deviations from the best-fit values given in Ref. 1, however they are consistent with the other experimental results.[Formula: see text]


2020 ◽  
Vol 35 (38) ◽  
pp. 2050311
Author(s):  
V. V. Vien

We propose a renormalizable [Formula: see text] extension of the Standard model with [Formula: see text] symmetry that leads to the successful cobimaximal lepton mixing ansatz, thus providing a predictive explanation for leptonic mixing observables. The smallness of the active neutrino masses and neutrino masses ordering are produced by the type-I seesaw mechanism at the tree-level. The obtained physical parameters are well consistent with the global fit of neutrino oscillation.1 The model is predictive in the sense that it reproduces the experimental values of neutrino parameters in which the reactor neutrino mixing angle [Formula: see text] get the best-fit value and the solar and atmospheric neutrino mixing angles have little deviations from the best-fit values given in Ref. 1, however, they are consistent with the other experimental results.[Formula: see text] The effective neutrino masses governing the neutrinoless double beta decay is predicted to be [Formula: see text] for normal hierarchy and [Formula: see text] for inverted hierarchy which are well consistent with the recent experimental limits on neutrinoless double beta decay.


1996 ◽  
Vol 11 (08) ◽  
pp. 675-686 ◽  
Author(s):  
DEBRUPA CHAKRAVERTY ◽  
ANIRBAN KUNDU

The scalar sector of the standard model is extended to include an arbitrary assortment of scalars. In the case where this assignment does not preserve p=1 at the tree-level, the departure from unity itself puts the most stringent constraint on the scalar sector, and where ptree=1 is maintained, useful bounds on the parameter space of the charged Higgs mass and the doublet-nondoublet mixing angle can arise from data on [Formula: see text], [Formula: see text] mixing and the ε parameter. These constraints turn out to be comparable (and in some cases, better) to those obtained from [Formula: see text] data.


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