Soft L{sub e}−L{sub μ}−L{sub τ} flavour symmetry breaking and sterile neutrino keV Dark Matter
Lindner, Manfred; Merle, Alexander; Niro, Viviana E-mail: amerle@kth.se
2011-01-01
We discuss how a L{sub e}−L{sub μ}−L{sub τ} flavour symmetry that is softly broken leads to keV sterile neutrinos, which are a prime candidate for Warm Dark Matter. This is to our knowledge the first model where flavour symmetries are applied simultaneously to active and sterile neutrinos explaining at the same time active neutrino properties and this peculiar Dark Matter scenario. The essential point is that different scales of the symmetry breaking and the symmetry preserving entries in the mass matrix lead to one right-handed neutrino which is nearly massless compared to the other two. Furthermore, we naturally predict vanishing θ{sub 13} and maximal θ{sub 23}, while the correct value of θ{sub 12} must come from the mixing of the charged leptons. We can furthermore predict an exact mass spectrum for the light neutrinos, which will be testable in the very near future.
Neutrino Mass and Flavour Models
King, Stephen F.
2010-02-10
We survey some of the recent promising developments in the search for the theory behind neutrino mass and tri-bimaximal mixing, and indeed all fermion masses and mixing. We focus in particular on models with discrete family symmetry and unification, and show how such models can also solve the SUSY flavour and CP problems. We also discuss the theoretical implications of the measurement of a non-zero reactor angle, as hinted at by recent experimental measurements.
Flavour dependent gauged radiative neutrino mass model
NASA Astrophysics Data System (ADS)
Baek, Seungwon; Okada, Hiroshi; Yagyu, Kei
2015-04-01
We propose a one-loop induced radiative neutrino mass model with anomaly free flavour dependent gauge symmetry: μ minus τ symmetry U(1) μ- τ . A neutrino mass matrix satisfying current experimental data can be obtained by introducing a weak isospin singlet scalar boson that breaks U(1) μ- τ symmetry, an inert doublet scalar field, and three right-handed neutrinos in addition to the fields in the standard model. We find that a characteristic structure appears in the neutrino mass matrix: two-zero texture form which predicts three non-zero neutrino masses and three non-zero CP-phases from five well measured experimental inputs of two squared mass differences and three mixing angles. Furthermore, it is clarified that only the inverted mass hierarchy is allowed in our model. In a favored parameter set from the neutrino sector, the discrepancy in the muon anomalous magnetic moment between the experimental data and the the standard model prediction can be explained by the additional neutral gauge boson loop contribution with mass of order 100 MeV and new gauge coupling of order 10-3.
Neutrinos and flavor symmetries
Tanimoto, Morimitsu
2015-07-15
We discuss the recent progress of flavor models with the non-Abelian discrete symmetry in the lepton sector focusing on the θ{sub 13} and CP violating phase. In both direct approach and indirect approach of the flavor symmetry, the non-vanishing θ{sub 13} is predictable. The flavor symmetry with the generalised CP symmetry can also predicts the CP violating phase. We show the phenomenological analyses of neutrino mixing for the typical flavor models.
Neutrinos and flavor symmetries
NASA Astrophysics Data System (ADS)
Tanimoto, Morimitsu
2015-07-01
We discuss the recent progress of flavor models with the non-Abelian discrete symmetry in the lepton sector focusing on the θ13 and CP violating phase. In both direct approach and indirect approach of the flavor symmetry, the non-vanishing θ13 is predictable. The flavor symmetry with the generalised CP symmetry can also predicts the CP violating phase. We show the phenomenological analyses of neutrino mixing for the typical flavor models.
Neutrino observables from predictive flavour patterns
NASA Astrophysics Data System (ADS)
Cebola, Luís M.; Emmanuel-Costa, David; Felipe, Ricardo González
2016-03-01
We look for predictive flavour patterns of the effective Majorana neutrino mass matrix that are compatible with current neutrino oscillation data. Our search is based on the assumption that the neutrino mass matrix contains equal elements and a minimal number of parameters, in the flavour basis where the charged lepton mass matrix is diagonal and real. Three unique patterns that can successfully explain neutrino observables at the 3\\upsigma confidence level with just three physical parameters are presented. Neutrino textures described by four and five parameters are also studied. The predictions for the lightest neutrino mass, the effective mass parameter in neutrinoless double beta decays and for the CP-violating phases in the leptonic mixing are given.
Neutrino physics: A deliberate mix-up in flavour
NASA Astrophysics Data System (ADS)
O'Keeffe, Helen
2016-05-01
Neutrinos come in three 'flavours', as do antineutrinos, and they all change flavour as they travel. New measurements of the mixing of different neutrinos may help to explain why our Universe is made of matter and not antimatter.
Neutrino-flavoured sneutrino dark matter
NASA Astrophysics Data System (ADS)
March-Russell, John; McCabe, Christopher; McCullough, Matthew
2010-03-01
A simple theory of supersymmetric dark matter (DM) naturally linked to neutrino flavour physics is studied. The DM sector comprises a spectrum of mixed lhd-rhd sneutrino states where both the sneutrino flavour structure and mass splittings are determined by the associated neutrino masses and mixings. Prospects for indirect detection from solar capture are good due to a large sneutrino-nucleon cross-section afforded by the inelastic splitting (solar capture limits exclude an explanation of DAMA/LIBRA). We find parameter regions where all heavier states will have decayed, leaving only one flavour mixture of sneutrino as the candidate DM. Such regions have a unique ‘smoking gun’ signature — sneutrino annihilation in the Sun produces a pair of neutrino mass eigenstates free from vacuum oscillations, with the potential for detection at neutrino telescopes through the observation of a hard spectrum of ν μ and ν τ (for a normal neutrino hierarchy). Next generation direct detection experiments can explore much of the parameter space through both elastic and inelastic scattering. We show in detail that the observed neutrino masses and mixings can arise as a consequence of supersymmetry breaking effects in the sneutrino DM sector, consistent with all experimental constraints.
Relic neutrino decoupling with flavour oscillations revisited
NASA Astrophysics Data System (ADS)
de Salas, Pablo F.; Pastor, Sergio
2016-07-01
We study the decoupling process of neutrinos in the early universe in the presence of three-flavour oscillations. The evolution of the neutrino spectra is found by solving the corresponding momentum-dependent kinetic equations for the neutrino density matrix, including for the first time the proper collision integrals for both diagonal and off-diagonal elements. This improved calculation modifies the evolution of the off-diagonal elements of the neutrino density matrix and changes the deviation from equilibrium of the frozen neutrino spectra. However, it does not vary the contribution of neutrinos to the cosmological energy density in the form of radiation, usually expressed in terms of the effective number of neutrinos, Neff. We find a value of Neff = 3.045, in agreement with previous theoretical calculations and consistent with the latest analysis of Planck data. This result does not depend on the ordering of neutrino masses. We also consider the effect of non-standard neutrino-electron interactions (NSI), predicted in many theoretical models where neutrinos acquire mass. For two sets of NSI parameters allowed by present data, we find that Neff can be reduced down to 3.040 or enhanced up to 3.059.
Matter inflation with A{sub 4} flavour symmetry breaking
Antusch, Stefan; Nolde, David E-mail: david.nolde@unibas.ch
2013-10-01
We discuss model building in tribrid inflation, which is a framework for realising inflation in the matter sector of supersymmetric particle physics models. The inflaton is a D-flat combination of matter fields, and inflation ends by a phase transition in which some Higgs field obtains a vacuum expectation value. We first describe the general procedure for implementing tribrid inflation in realistic models of particle physics that can be applied to a wide variety of BSM particle physics models around the GUT scale. We then demonstrate how the procedure works for an explicit lepton flavour model based on an A{sub 4} family symmetry. The model is both predictive and phenomenologically viable, and illustrates how tribrid inflation connects cosmological and particle physics parameters. In particular, it predicts a relation between the neutrino Yukawa coupling and the running of the spectral index α{sub s}. We also show how topological defects from the flavour symmetry breaking can be avoided automatically.
SO(10) models with flavour symmetries: classification and examples
NASA Astrophysics Data System (ADS)
Ivanov, I. P.; Lavoura, L.
2016-10-01
Renormalizable SO(10) grand unified theory (GUT) models equipped with flavour symmetries are a popular framework for addressing the flavour puzzle. Usually, the flavour symmetry group has been an ad hoc choice, and no general arguments limiting this choice were known. In this paper, we establish the full list of flavour symmetry groups which may be enforced, without producing any further accidental symmetry, on the Yukawa-coupling matrices of an SO(10) GUT with arbitrary numbers of scalar multiplets in the {{10}}, \\bar{{{126}}}, and {{120}} representations of SO(10). For each of the possible discrete non-Abelian symmetry groups, we present examples of minimal models which do not run into obvious contradiction with the phenomenological fermion masses and mixings.
Resonant-Spin Flavour solutions to the Solar neutrino Problem
NASA Astrophysics Data System (ADS)
Miranda, O. G.
2002-07-01
Resonant spin-flavour solutions to the solar neutrino problem are introduced, in the framework of analytic solutions to the solar magneto-hydrodynamics equations. We study these solutions in a scheme with 3 effective parameters: the neutrino magnetic moment, the neutrino mass difference and mixing. We perform a fit of the solar neutrino data, including the recent SNO CC. We show how a rates-only analysis slightly flavours spin-flavour precession solutions over oscillations. In addition to the resonant solution, there is a new non-resonant solution in the dark-side. Both solutions lead to flat recoil energy spectra in excellent agreement with the latest SuperKamiokande data.
Neutrino properties and fundamental symmetries
Bowles, T.J.
1996-07-01
This is the final report of a three-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). There are two components to this work. The first is a development of a new detection scheme for neutrinos. The observed deficit of neutrinos from the Sun may be due to either a lack of understanding of physical processes in the Sun or may be due to neutrinos oscillating from one type to another during their transit from the Sun to the Earth. The Sudbury Neutrino Observatory (SNO) is designed to use a water Cerenkov detector employing one thousand tonnes of heavy water to resolve this question. The ability to distinguish muon and tau neutrinos from electron neutrinos is crucial in order to carry out a model-independent test of neutrino oscillations. We describe a developmental exploration of a novel technique to do this using {sup 3}He proportional counters. Such a method offers considerable advantages over the initially proposed method of using Cerenkov light from capture on NaCl in the SNO. The second component of this work is an exploration of optimal detector geometry for a time-reversal invariance experiment. The question of why time moves only in the forward direction is one of the most puzzling problems in modern physics. We know from particle physics measurements of the decay of kaons that there is a charge-parity symmetry that is violated in nature, implying time-reversal invariance violation. Yet, we do not understand the origin of the violation of this symmetry. To promote such an understanding, we are developing concepts and prototype apparatus for a new, highly sensitive technique to search for time-reversal-invariance violation in the beta decay of the free neutron. The optimized detector geometry is seven times more sensitive than that in previous experiments. 15 refs.
Impact of sterile neutrinos in lepton flavour violating processes
NASA Astrophysics Data System (ADS)
De Romeri, Valentina
2016-05-01
We discuss charged lepton flavour violating processes occurring in minimal extensions of the Standard Model via the addition of sterile fermions. We firstly investigate the possibility of their indirect detection at a future high-luminosity Z-factory (such as FCC-ee). Rare decays such as Z → l 1 ± l 2 ± can indeed be complementary to low-energy (high-intensity) observables of lepton flavour violation. We further consider a sterile neutrino-induced charged lepton flavour violating process occurring in the presence of muonic atoms: their (Coulomb enhanced) decay into a pair of electrons μ¯e¯ → e¯e¯. Our study reveals that, depending on their mass range and on the active-sterile mixing angles, sterile neutrinos can give significant contributions to the above mentioned observables, some of them even lying within present and future sensitivity of dedicated cLFV experiments and of FCC-ee.
Lepton Flavour Violation and electron EDM in SUSY with a non-abelian flavour symmetry
Calibbi, Lorenzo
2008-11-23
We present the lepton sector phenomenology of a supersymmetric flavour model based on a SU(3) horizontal symmetry. This model successfully reproduces the observed fermion masses and mixings, without introducing unacceptably large SUSY sources of flavour and CP violation. We show that the model, which is at present weakly constrained, predicts the electron EDM and {mu}{yields}e,y to be within the final sensitivity of the currently running experiments, at least for SUSY masses within the reach of the LHC.
Collective neutrino oscillations and spontaneous symmetry breaking
NASA Astrophysics Data System (ADS)
Duan, Huaiyu
2015-08-01
Neutrino oscillations in a hot and dense astrophysical environment such as a core-collapse supernova pose a challenging, seven-dimensional flavor transport problem. To make the problem even more difficult (and interesting), neutrinos can experience collective oscillations through nonlinear refraction in the dense neutrino medium in this environment. Significant progress has been made in the last decade towards the understanding of collective neutrino oscillations in various simplified neutrino gas models with imposed symmetries and reduced dimensions. However, a series of recent studies seem to have "reset" this progress by showing that these models may not be compatible with collective neutrino oscillations because the latter can break the symmetries spontaneously if they are not imposed. We review some of the key concepts of collective neutrino oscillations by using a few simple toy models. We also elucidate the breaking of spatial and directional symmetries in these models because of collective oscillations.
Models for neutrino mass with discrete symmetries
NASA Astrophysics Data System (ADS)
Morisi, S.
2011-08-01
Discrete non-abelian flavor symmetries give in a natural way tri-bimaximal (TBM) mixing as showed in a prototype model. However neutrino mass matrix pattern may be very different from the tri-bimaximal one if small deviations of TBM will be observed. We give the result of a model independent analysis for TBM neutrino mass pattern.
Discrete flavour symmetries from the Heisenberg group
NASA Astrophysics Data System (ADS)
Floratos, E. G.; Leontaris, G. K.
2016-04-01
Non-abelian discrete symmetries are of particular importance in model building. They are mainly invoked to explain the various fermion mass hierarchies and forbid dangerous superpotential terms. In string models they are usually associated to the geometry of the compactification manifold and more particularly to the magnetised branes in toroidal compactifications. Motivated by these facts, in this note we propose a unified framework to construct representations of finite discrete family groups based on the automorphisms of the discrete and finite Heisenberg group. We focus in particular, on the PSL2 (p) groups which contain the phenomenologically interesting cases.
S4 flavored CP symmetry for neutrinos
NASA Astrophysics Data System (ADS)
Mohapatra, R. N.; Nishi, C. C.
2012-10-01
A generalized CP symmetry for leptons is presented where CP transformations are part of an S4 symmetry that connects different families. We study its implications for lepton mixings in a gauge model realization of the idea using a type II seesaw for neutrino masses. The model predicts maximal atmospheric mixing, nonzero θ13 and maximal Dirac phase δD=±(π)/(2).
Flavour symmetries in a renormalizable SO(10) model
NASA Astrophysics Data System (ADS)
Ferreira, P. M.; Grimus, W.; Jurčiukonis, D.; Lavoura, L.
2016-05-01
In the context of a renormalizable supersymmetric SO (10) Grand Unified Theory, we consider the fermion mass matrices generated by the Yukawa couplings to a 10 ⊕ 120 ⊕ 126 ‾ representation of scalars. We perform a complete investigation of the possibilities of imposing flavour symmetries in this scenario; the purpose is to reduce the number of Yukawa coupling constants in order to identify potentially predictive models. We have found that there are only 14 inequivalent cases of Yukawa coupling matrices, out of which 13 cases are generated by Zn symmetries, with suitable n, and one case is generated by a Z2 ×Z2 symmetry. A numerical analysis of the 14 cases reveals that only two of them-dubbed A and B in the present paper-allow good fits to the experimentally known fermion masses and mixings.
Neutrino mass, mixing and discrete symmetries
NASA Astrophysics Data System (ADS)
Smirnov, Alexei Y.
2013-07-01
Status of the discrete symmetry approach to explanation of the lepton masses and mixing is summarized in view of recent experimental results, in particular, establishing relatively large 1-3 mixing. The lepton mixing can originate from breaking of discrete flavor symmetry Gf to different residual symmetries Gl and Gv in the charged lepton and neutrino sectors. In this framework the symmetry group condition has been derived which allows to get relations between the lepton mixing elements immediately without explicit model building. The condition has been applied to different residual neutrino symmetries Gv. For generic (mass independent) Gv = Z2 the condition leads to two relations between the mixing parameters and fixes one column of the mixing matrix. In the case of Gv = Z2 × Z2 the condition fixes the mixing matrix completely. The non-generic (mass spectrum dependent) Gv lead to relations which include mixing angles, neutrino masses and Majorana phases. The symmetries Gl, Gv, Gf are identified which lead to the experimentally observed values of the mixing angles and allow to predict the CP phase.
Neutrino mixing from C P symmetry
NASA Astrophysics Data System (ADS)
Chen, Peng; Yao, Chang-Yuan; Ding, Gui-Jun
2015-10-01
The neutrino mass matrix has remnant C P symmetry expressed in terms of the lepton mixing matrix, and vice versa the remnant C P transformations allow us to reconstruct the mixing matrix. We study the scenario that all four remnant C P transformations are preserved by the neutrino mass matrix. The most general parametrization of remnant C P transformations is presented. The lepton mixing matrix is completely fixed by the remnant C P , and its explicit form is derived. The necessary and sufficient condition for conserved Dirac C P violating phase is found. If the Klein four flavor symmetry generated by the postulated remnant C P transformations arises from a finite flavor symmetry group, the phenomenologically viable lepton flavor mixing would be the trimaximal pattern, both Dirac C P phase δC P and Majorana phase α31 are either 0 or π while another Majorana phase α21 is a rational multiple of π . These general results are confirmed to be true in the case that the finite flavor symmetry group is Δ (6 n2).
Leptonic mixing, family symmetries, and neutrino phenomenology
Medeiros Varzielas, I. de; Gonzalez Felipe, R.; Serodio, H.
2011-02-01
Tribimaximal leptonic mixing is a mass-independent mixing scheme consistent with the present solar and atmospheric neutrino data. By conveniently decomposing the effective neutrino mass matrix associated to it, we derive generic predictions in terms of the parameters governing the neutrino masses. We extend this phenomenological analysis to other mass-independent mixing schemes which are related to the tribimaximal form by a unitary transformation. We classify models that produce tribimaximal leptonic mixing through the group structure of their family symmetries in order to point out that there is often a direct connection between the group structure and the phenomenological analysis. The type of seesaw mechanism responsible for neutrino masses plays a role here, as it restricts the choices of family representations and affects the viability of leptogenesis. We also present a recipe to generalize a given tribimaximal model to an associated model with a different mass-independent mixing scheme, which preserves the connection between the group structure and phenomenology as in the original model. This procedure is explicitly illustrated by constructing toy models with the transpose tribimaximal, bimaximal, golden ratio, and hexagonal leptonic mixing patterns.
Warped flavor symmetry predictions for neutrino physics
NASA Astrophysics Data System (ADS)
Chen, Peng; Ding, Gui-Jun; Rojas, Alma D.; Vaquera-Araujo, C. A.; Valle, J. W. F.
2016-01-01
A realistic five-dimensional warped scenario with all standard model fields propagating in the bulk is proposed. Mass hierarchies would in principle be accounted for by judicious choices of the bulk mass parameters, while fermion mixing angles are restricted by a Δ(27) flavor symmetry broken on the branes by flavon fields.The latter gives stringent predictions for the neutrino mixing parameters, and the Dirac CP violation phase, all described in terms of only two independent parameters at leading order. The scheme also gives an adequate CKM fit and should be testable within upcoming oscillation experiments.
Leptogenesis with heavy neutrino flavours: from density matrix to Boltzmann equations
Blanchet, Steve; Bari, Pasquale Di; Jones, David A.; Marzola, Luca E-mail: pdb1d08@soton.ac.uk E-mail: daj1g08@soton.ac.uk
2013-01-01
Leptogenesis with heavy neutrino flavours is discussed within a density matrix formalism. We write the density matrix equation, describing the generation of the matter-antimatter asymmetry, for an arbitrary choice of the right-handed (RH) neutrino masses. For hierarchical RH neutrino masses lying in the fully flavoured regimes, this reduces to multiple-stage Boltzmann equations. In this case we recover and extend results previously derived within a quantum state collapse description. We confirm the generic existence of phantom terms. However, taking into account the effect of gauge interactions, we show that they are washed out at the production with a wash-out rate that is halved compared to that one acting on the total asymmetry. In the N{sub 1}-dominated scenario they cancel without contributing to the final baryon asymmetry. In other scenarios they do not in general and they have to be taken into account. We also confirm that there is a (orthogonal) component in the asymmetry produced by the heavier RH neutrinos which completely escapes the washout from the lighter RH neutrinos and show that phantom terms additionally contribute to it. The other (parallel) component is washed out with the usual exponential factor, even for weak washout. Finally, as an illustration, we study the two RH neutrino model in the light of the above findings, showing that phantom terms can contribute to the final asymmetry also in this case.
Leptogenesis with heavy neutrino flavours: from density matrix to Boltzmann equations
NASA Astrophysics Data System (ADS)
Blanchet, Steve; Di Bari, Pasquale; Jones, David A.; Marzola, Luca
2013-01-01
Leptogenesis with heavy neutrino flavours is discussed within a density matrix formalism. We write the density matrix equation, describing the generation of the matter-antimatter asymmetry, for an arbitrary choice of the right-handed (RH) neutrino masses. For hierarchical RH neutrino masses lying in the fully flavoured regimes, this reduces to multiple-stage Boltzmann equations. In this case we recover and extend results previously derived within a quantum state collapse description. We confirm the generic existence of phantom terms. However, taking into account the effect of gauge interactions, we show that they are washed out at the production with a wash-out rate that is halved compared to that one acting on the total asymmetry. In the N1-dominated scenario they cancel without contributing to the final baryon asymmetry. In other scenarios they do not in general and they have to be taken into account. We also confirm that there is a (orthogonal) component in the asymmetry produced by the heavier RH neutrinos which completely escapes the washout from the lighter RH neutrinos and show that phantom terms additionally contribute to it. The other (parallel) component is washed out with the usual exponential factor, even for weak washout. Finally, as an illustration, we study the two RH neutrino model in the light of the above findings, showing that phantom terms can contribute to the final asymmetry also in this case.
Generalized hidden Z{sub 2} symmetry of neutrino mixing
Dicus, Duane A.; Ge Shaofeng; Repko, Wayne W.
2011-05-01
We explore the consequences of the neutrino mass matrix having a hidden Z{sub 2} symmetry and one zero eigenvalue. When implemented, these two conditions give relations among the mixing angles. In addition, fitting these relations to the existing oscillation data allows limits to be placed on the parameter of the symmetry.
Peccei-Quinn symmetry, dark matter, and neutrino mass
Ma, Ernest
2014-06-24
It is pointed out that a residual Z{sub 2} symmetry of the usual anomalous Peccei-Quinn U(1){sub PQ} symmetry (which solves the strong CP problem) may be used for an absolutely stable heavy dark-matter particle in addition to the long-lived axion. The same Z{sub 2} symmetry may also be used to generate radiative neutrino mass.
Neutrino helicity reversal and fundamental symmetries
NASA Astrophysics Data System (ADS)
Jentschura, U. D.; Wundt, B. J.
2014-07-01
A rather elusive helicity reversal occurs in a gedanken experiment in which a massive left-handed Dirac neutrino, traveling at a velocity u < c, is overtaken on a highway by a speeding vehicle (traveling at velocity v with u < v < c). Namely, after passing the neutrino, looking back, one would see a right-handed neutrino (which has never been observed in nature). The Lorentz-invariant mass of the right-handed neutrino is still the same as before the passing. The gedanken experiment thus implies the existence of right-handed, light neutrinos, which are not completely sterile. Furthermore, overtaking a bunch of massive right-handed Dirac neutrinos leads to gradual de-sterilization. We discuss the helicity reversal and the concomitant sterilization and de-sterilization mechanisms by way of an illustrative example calculation, with a special emphasis on massive Dirac and Majorana neutrinos. We contrast the formalism with a modified Dirac neutrino described by a Dirac equation with a pseudoscalar mass term proportional to the fifth current.
Crucial role of neutrinos in the electroweak symmetry breaking
Smetana, Adam
2013-12-30
Not only the top-quark condensate appears to be the natural significant source of dynamical electroweak symmetry breaking. Provided the seesaw scenario, the neutrinos can have their Dirac masses large enough so that their condensates contribute significantly to the electroweak scale as well. We address the question of a phenomenological feasibility of the top-quark and neutrino condensation conspiracy against the electroweak symmetry within the simplifying two-composite-Higgs-doublet model. Mandatory is to reproduce the masses of electroweak gauge bosons, the top-quark mass and the recently observed scalar mass of 125 GeV, and to satisfy the upper limits on absolute value of active neutrino masses. To accomplish that, the number of right-handed neutrinos participating on the seesaw mechanism turns out to be rather large, O(100–1000)
Large transition magnetic moment of the neutrino from horizontal symmetry
NASA Astrophysics Data System (ADS)
Babu, K. S.; Mohapatra, Rabindra N.
1990-12-01
The apparent anticorrelation of the solar-neutrino signal with the 11-yr sunspot cycle observed by Davis can be understood if the electron neutrino has a large magnetic moment. We discuss extensions of the standard model, where the existence of a leptonic SU(2)H-horizontal symmetry between the electron and muon generations provides a way to understand such a large magnetic moment, while keeping the neutrino mass naturally small. A global le-lμ symmetry (li=ith lepton number) is maintained even after spontaneous gauge symmetry breaking, so that the neutrino is of Zeldovich-Konopinski-Mahmoud type with m2νe-m2νμ=0. This condition automatically guarantees that the neutrino spin precession in the magnetic field of the Sun is not suppressed. Of the two extensions of the standard model that we discuss, the first one is a local SU(2)H model with the horizontal symmetry broken completely at a TeV scale. We show how a global U(1)le-lμ can be maintained although le-lμ is a subgroup of the gauged SU(2)H. The second example is the minimal supersymmetric extension of the standard model with R-parity-violating [but (le-lμ)-conserving] interactions. An approximate SU(2)H symmetry between the e-μ families is imposed in order to suppress the neutrino mass, but not its magnetic moment. We provide a detailed theoretical and phenomenological investigation of these two models and discuss their tests at the colliders as well as in low-energy experiments. The models generally predict mνe~=1-10 eV and the existence of charged scalar particles in the mass range of 100 GeV.
Classically conformal radiative neutrino model with gauged B - L symmetry
NASA Astrophysics Data System (ADS)
Okada, Hiroshi; Orikasa, Yuta
2016-09-01
We propose a classically conformal model in a minimal radiative seesaw, in which we employ a gauged B - L symmetry in the standard model that is essential in order to work the Coleman-Weinberg mechanism well that induces the B - L symmetry breaking. As a result, nonzero Majorana mass term and electroweak symmetry breaking simultaneously occur. In this framework, we show a benchmark point to satisfy several theoretical and experimental constraints. Here theoretical constraints represent inert conditions and Coleman-Weinberg condition. Experimental bounds come from lepton flavor violations (especially μ → eγ), the current bound on the Z‧ mass at the CERN Large Hadron Collider, and neutrino oscillations.
Leptogenesis and residual CP symmetry
NASA Astrophysics Data System (ADS)
Chen, Peng; Ding, Gui-Jun; King, Stephen F.
2016-03-01
We discuss flavour dependent leptogenesis in the framework of lepton flavour models based on discrete flavour and CP symmetries applied to the type-I seesaw model. Working in the flavour basis, we analyse the case of two general residual CP symmetries in the neutrino sector, which corresponds to all possible semi-direct models based on a preserved Z 2 in the neutrino sector, together with a CP symmetry, which constrains the PMNS matrix up to a single free parameter which may be fixed by the reactor angle. We systematically study and classify this case for all possible residual CP symmetries, and show that the R-matrix is tightly constrained up to a single free parameter, with only certain forms being consistent with successful leptogenesis, leading to possible connections between leptogenesis and PMNS parameters. The formalism is completely general in the sense that the two residual CP symmetries could result from any high energy discrete flavour theory which respects any CP symmetry. As a simple example, we apply the formalism to a high energy S 4 flavour symmetry with a generalized CP symmetry, broken to two residual CP symmetries in the neutrino sector, recovering familiar results for PMNS predictions, together with new results for flavour dependent leptogenesis.
Minimal resonant leptogenesis and lepton flavour violation
Deppisch, Frank F.; Pilaftsis, Apostolos
2012-07-27
We discuss minimal non-supersymmetric models of resonant leptogenesis, based on an approximate flavour symmetries. As an illustrative example, we consider a resonant {tau}-leptogenesis model, compatible with universal right-handed neutrino masses at the GUT scale, where the required heavy-neutrino mass splittings are generated radiatively. In particular, we explicitly demonstrate, how a minimum number of three heavy Majorana neutrinos is needed, in order to obtain successful leptogenesis and experimentally testable rates for processes of lepton flavour violation, such as {mu}{yields}e{gamma} and {mu}{yields}e conversion in nuclei.
Implications of recent data on neutrino mixing and lepton flavour violating decays for the Zee model
NASA Astrophysics Data System (ADS)
He, Xiao-Gang; Majee, Swarup Kumar
2012-03-01
We study implications of recent data on neutrino mixing from T2K, MINOS, Double Chooz and μ → eγ from MEG for the Zee model. The simplest version of this model has been shown to be ruled out by experimental data some time ago. The general Zee model is still consistent with recent data. We demonstrate this with a constrained Zee model based on naturalness consideration. In this constrained model, only inverted mass hierarchy for neutrino masses is allowed, and θ 13 must be non-zero in order to have correct ratio for neutrino mass-squared differences and for mixing in solar and atmospherical neutrino oscillations. The best-fit value of our model for θ 13 is 8.91° from T2K and MINOS data, very close to the central value obtained by Double Chooz experiment. There are solutions with non-zero CP violation with the Jarlskog parameter predicted in the range ±0.039, ±0.044 and ±0.048 respectively for a 1 σ, 2 σ and 3 σ ranges of other input parameters. However, without any constraint on the θ 13-parameter above respective ranges become ±0.049, ±0.053 and ±0.056. We analyse different cases to obtain a branching ratio for μ → eγ close to the recent MEG bound. We also discuss other radiative as well as the charged trilepton flavour violating decay modes of the τ-lepton.
Form invariance and symmetry in the neutrino mass matrix
Lashin, E. I.; Nasri, S.; Malkawi, E.; Chamoun, N.
2011-01-01
We present the general form of the unitary matrices keeping invariant the Majorana neutrino mass matrix of specific texture suitable for explaining oscillation data. In the case of the tri-bimaximal pattern with two degenerate masses, we give a specific realization of the underlying U(1) symmetry which can be uplifted to a symmetry in a complete theory including charged leptons. For this, we present a model with three light SM-like Higgs doublets and one heavy Higgs triplet and find that one can accommodate the hierarchy of the charged-lepton masses. The lepton mass spectrum can also be achieved in another model extending the SM with three SM-singlet scalars transforming nontrivially under the flavor symmetry. We discuss how such a model has room for generating enough baryon asymmetry through leptogenesis in the framework of type-I and -II seesaw mechanisms.
PQ-symmetry for a small Dirac neutrino mass, dark radiation and cosmic neutrinos
Park, Wan-Il
2014-06-01
We propose a supersymmetric scenario in which the small Yukawa couplings for the Dirac neutrino mass term are generated by the spontaneous-breaking of Pecci-Quinn symmetry. In this scenario, a right amount of dark matter relic density can be obtained by either right-handed sneutrino or axino LSP, and a sizable amount of axion dark radiation can be obtained. Interestingly, the decay of right-handed sneutrino NLSP to axino LSP is delayed to around the present epoch, and can leave an observable cosmological background of neutrinos at the energy scale of O(10−100) GeV.
True Neutrality as a New Type of Flavour
NASA Astrophysics Data System (ADS)
Sharafiddinov, Rasulkhozha S.
2016-06-01
A classification of leptonic currents with respect to C-operation requires the separation of elementary particles into the two classes of vector C-even and axial-vector C-odd character. Their nature has been created so that to each type of lepton corresponds a kind of neutrino. Such pairs are united in families of a different C-parity. Unlike the neutrino of a vector type, any C-noninvariant Dirac neutrino must have his Majorana neutrino. They constitute the purely neutrino families. We discuss the nature of a corresponding mechanism responsible for the availability in all types of axial-vector particles of a kind of flavour which distinguishes each of them from others by a true charge characterized by a quantum number conserved at the interactions between the C-odd fermion and the field of emission of the corresponding types of gauge bosons. This regularity expresses the unidenticality of truly neutral neutrino and antineutrino, confirming that an internal symmetry of a C-noninvariant particle is described by an axial-vector space. Thereby, a true flavour together with the earlier known lepton flavour predicts the existence of leptonic strings and their birth in single and double beta decays as a unity of flavour and gauge symmetry laws. Such a unified principle explains the availability of a flavour symmetrical mode of neutrino oscillations.
Bimaximal Neutrino Mixing and Weak Complementarity with S{sub 4} Discrete Symmetry
Merlo, Luca
2010-02-10
The neutrino oscillation data are well explained by the tri-bimaximal pattern. Recently a paper appeared showing that also the bimaximal pattern could be a very good starting point in order to describe the lepton mixing. In this paper I review both the flavour structures and then I present an explicit model.
Axial symmetry breaking in self-induced flavor conversionof supernova neutrino fluxes.
Raffelt, Georg; Sarikas, Srdjan; de Sousa Seixas, David
2013-08-30
Neutrino-neutrino refraction causes self-induced flavor conversion in dense neutrino fluxes. For the first time, we include the azimuth angle of neutrino propagation as an explicit variable and find a new generic multi-azimuth-angle instability which, for simple spectra, occurs in the normal neutrino mass hierarchy. Matter suppression of this instability in supernovae requires larger densities than the traditional bimodal case. The new instability shows explicitly that solutions of the equations for collective flavor oscillations need not inherit the symmetries of initial or boundary conditions. This change of paradigm requires reconsideration of numerous results in this field.
NASA Astrophysics Data System (ADS)
Aartsen, M. G.; Abraham, K.; Ackermann, M.; Adams, J.; Aguilar, J. A.; Ahlers, M.; Ahrens, M.; Altmann, D.; Andeen, K.; Anderson, T.; Ansseau, I.; Anton, G.; Archinger, M.; Arguelles, C.; Arlen, T. C.; Auffenberg, J.; Axani, S.; Bai, X.; Barwick, S. W.; Baum, V.; Bay, R.; Beatty, J. J.; Becker Tjus, J.; Becker, K.-H.; BenZvi, S.; Berghaus, P.; Berley, D.; Bernardini, E.; Bernhard, A.; Besson, D. Z.; Binder, G.; Bindig, D.; Bissok, M.; Blaufuss, E.; Blot, S.; Boersma, D. J.; Bohm, C.; Börner, M.; Bos, F.; Bose, D.; Böser, S.; Botner, O.; Braun, J.; Brayeur, L.; Bretz, H.-P.; Burgman, A.; Casey, J.; Casier, M.; Cheung, E.; Chirkin, D.; Christov, A.; Clark, K.; Classen, L.; Coenders, S.; Collin, G. H.; Conrad, J. M.; Cowen, D. F.; Cruz Silva, A. H.; Daughhetee, J.; Davis, J. C.; Day, M.; de André, J. P. A. M.; De Clercq, C.; del Pino Rosendo, E.; Dembinski, H.; De Ridder, S.; Desiati, P.; de Vries, K. D.; de Wasseige, G.; de With, M.; DeYoung, T.; Díaz-Vélez, J. C.; di Lorenzo, V.; Dujmovic, H.; Dumm, J. P.; Dunkman, M.; Eberhardt, B.; Ehrhardt, T.; Eichmann, B.; Euler, S.; Evenson, P. A.; Fahey, S.; Fazely, A. R.; Feintzeig, J.; Felde, J.; Filimonov, K.; Finley, C.; Flis, S.; Fösig, C.-C.; Franckowiak, A.; Fuchs, T.; Gaisser, T. K.; Gaior, R.; Gallagher, J.; Gerhardt, L.; Ghorbani, K.; Giang, W.; Gladstone, L.; Glagla, M.; Glüsenkamp, T.; Goldschmidt, A.; Golup, G.; Gonzalez, J. G.; Góra, D.; Grant, D.; Griffith, Z.; Haack, C.; Haj Ismail, A.; Hallgren, A.; Halzen, F.; Hansen, E.; Hansmann, B.; Hansmann, T.; Hanson, K.; Hebecker, D.; Heereman, D.; Helbing, K.; Hellauer, R.; Hickford, S.; Hignight, J.; Hill, G. C.; Hoffman, K. D.; Hoffmann, R.; Holzapfel, K.; Homeier, A.; Hoshina, K.; Huang, F.; Huber, M.; Huelsnitz, W.; Hultqvist, K.; In, S.; Ishihara, A.; Jacobi, E.; Japaridze, G. S.; Jeong, M.; Jero, K.; Jones, B. J. P.; Jurkovic, M.; Kappes, A.; Karg, T.; Karle, A.; Katz, U.; Kauer, M.; Keivani, A.; Kelley, J. L.; Kemp, J.; Kheirandish, A.; Kim, M.; Kintscher, T.; Kiryluk, J.; Kittler, T.; Klein, S. R.; Kohnen, G.; Koirala, R.; Kolanoski, H.; Konietz, R.; Köpke, L.; Kopper, C.; Kopper, S.; Koskinen, D. J.; Kowalski, M.; Krings, K.; Kroll, M.; Krückl, G.; Krüger, C.; Kunnen, J.; Kunwar, S.; Kurahashi, N.; Kuwabara, T.; Labare, M.; Lanfranchi, J. L.; Larson, M. J.; Lennarz, D.; Lesiak-Bzdak, M.; Leuermann, M.; Leuner, J.; Lu, L.; Lünemann, J.; Madsen, J.; Maggi, G.; Mahn, K. B. M.; Mancina, S.; Mandelartz, M.; Maruyama, R.; Mase, K.; Maunu, R.; McNally, F.; Meagher, K.; Medici, M.; Meier, M.; Meli, A.; Menne, T.; Merino, G.; Meures, T.; Miarecki, S.; Middell, E.; Mohrmann, L.; Montaruli, T.; Moulai, M.; Nahnhauer, R.; Naumann, U.; Neer, G.; Niederhausen, H.; Nowicki, S. C.; Nygren, D. R.; Obertacke Pollmann, A.; Olivas, A.; Omairat, A.; O'Murchadha, A.; Palczewski, T.; Pandya, H.; Pankova, D. V.; Penek, Ö.; Pepper, J. A.; Pérez de los Heros, C.; Pfendner, C.; Pieloth, D.; Pinat, E.; Posselt, J.; Price, P. B.; Przybylski, G. T.; Quinnan, M.; Raab, C.; Rädel, L.; Rameez, M.; Rawlins, K.; Reimann, R.; Relich, M.; Resconi, E.; Rhode, W.; Richman, M.; Riedel, B.; Robertson, S.; Rongen, M.; Rott, C.; Ruhe, T.; Ryckbosch, D.; Rysewyk, D.; Sabbatini, L.; Sanchez Herrera, S. E.; Sandrock, A.; Sandroos, J.; Sarkar, S.; Satalecka, K.; Schimp, M.; Schlunder, P.; Schmidt, T.; Schoenen, S.; Schöneberg, S.; Schönwald, A.; Schumacher, L.; Seckel, D.; Seunarine, S.; Soldin, D.; Song, M.; Spiczak, G. M.; Spiering, C.; Stahlberg, M.; Stamatikos, M.; Stanev, T.; Stasik, A.; Steuer, A.; Stezelberger, T.; Stokstad, R. G.; Stößl, A.; Ström, R.; Strotjohann, N. L.; Sullivan, G. W.; Sutherland, M.; Taavola, H.; Taboada, I.; Tatar, J.; Tenholt, F.; Ter-Antonyan, S.; Terliuk, A.; Tešić, G.; Tilav, S.; Toale, P. A.; Tobin, M. N.; Toscano, S.; Tosi, D.; Tselengidou, M.; Turcati, A.; Unger, E.; Usner, M.; Vallecorsa, S.; Vandenbroucke, J.; van Eijndhoven, N.; Vanheule, S.; van Rossem, M.; van Santen, J.; Veenkamp, J.; Vehring, M.; Voge, M.; Vraeghe, M.; Walck, C.; Wallace, A.; Wallraff, M.; Wandkowsky, N.; Weaver, Ch.; Wendt, C.; Westerhoff, S.; Whelan, B. J.; Wickmann, S.; Wiebe, K.; Wiebusch, C. H.; Wille, L.; Williams, D. R.; Wills, L.; Wissing, H.; Wolf, M.; Wood, T. R.; Woolsey, E.; Woschnagg, K.; Xu, D. L.; Xu, X. W.; Xu, Y.; Yanez, J. P.; Yodh, G.; Yoshida, S.; Zoll, M.
2016-10-01
We present the first IceCube search for a signal of dark matter annihilations in the Milky Way using all-flavour neutrino-induced particle cascades. The analysis focuses on the DeepCore sub-detector of IceCube, and uses the surrounding IceCube strings as a veto region in order to select starting events in the DeepCore volume. We use 329 live-days of data from IceCube operating in its 86-string configuration during 2011-2012. No neutrino excess is found, the final result being compatible with the background-only hypothesis. From this null result, we derive upper limits on the velocity-averaged self-annihilation cross-section, < σ _A v rangle , for dark matter candidate masses ranging from 30 GeV up to 10 TeV, assuming both a cuspy and a flat-cored dark matter halo profile. For dark matter masses between 200 GeV and 10 TeV, the results improve on all previous IceCube results on < σ _A v rangle , reaching a level of 10^{-23} cm^3 s^{-1}, depending on the annihilation channel assumed, for a cusped NFW profile. The analysis demonstrates that all-flavour searches are competitive with muon channel searches despite the intrinsically worse angular resolution of cascades compared to muon tracks in IceCube.
Lepton mass and mixing in a neutrino mass model based on S4 flavor symmetry
NASA Astrophysics Data System (ADS)
Vien, V. V.
2016-03-01
We study a neutrino mass model based on S4 flavor symmetry which accommodates lepton mass, mixing with nonzero θ13 and CP violation phase. The spontaneous symmetry breaking in the model is imposed to obtain the realistic neutrino mass and mixing pattern at the tree-level with renormalizable interactions. Indeed, the neutrinos get small masses from one SU(2)L doublet and two SU(2)L singlets in which one being in 2̲ and the two others in 3̲ under S4 with both the breakings S4 → S3 and S4 → Z3 are taken place in charged lepton sector and S4 →𝒦 in neutrino sector. The model also gives a remarkable prediction of Dirac CP violation δCP = π 2 or -π 2 in both the normal and inverted spectrum which is still missing in the neutrino mixing matrix. The relation between lepton mixing angles is also represented.
Constraining a type I seesaw model with A4 flavor symmetry from neutrino data and leptogenesis
NASA Astrophysics Data System (ADS)
Kalita, Rupam; Borah, Debasish
2015-09-01
We study a type I seesaw model of neutrino masses within the framework of A4 flavor symmetry. Incorporating the presence of both singlet and triplet flavons under A4 symmetry, we construct the leptonic mass matrices involved in the type I seesaw mechanism. We then construct the light neutrino mass matrix using the 3 σ values of neutrino oscillation parameters keeping the presently undetermined parameters, namely, the lightest neutrino mass mlightest , one Dirac CP phase δ , and two Majorana phases α ,β , as free parameters. Comparing the mass matrices derived using A4 parameters as well as light neutrino parameters, we then evaluate all the A4 parameters in terms of light neutrino parameters. Assuming some specific vacuum alignments of the A4 triplet flavon field, we then numerically evaluate all the free parameters in the light neutrino sector, using them to find out the remaining A4 parameters. We then use the numerical values of these parameters to calculate baryon asymmetry through the mechanism of leptogenesis. We constrain not only the A4 vacuum alignments from the requirement of successful leptogenesis, but also the free parameters in the light neutrino sector (mlightest,δ ,α ,β ) to a certain range of values. These values can be tested in ongoing and future neutrino experiments, providing a way to discriminate between different possible A4 vacuum alignments discussed in this work.
Relating quarks and leptons with the T7 flavour group
NASA Astrophysics Data System (ADS)
Bonilla, Cesar; Morisi, Stefano; Peinado, Eduardo; Valle, J. W. F.
2015-03-01
In this letter we present a model for quarks and leptons based on T7 as flavour symmetry, predicting a canonical mass relation between charged leptons and down-type quarks proposed earlier. Neutrino masses are generated through a Type-I seesaw mechanism, with predicted correlations between the atmospheric mixing angle and neutrino masses. Compatibility with oscillation results leads to lower bounds for the lightest neutrino mass as well as for the neutrinoless double beta decay rates, even for normal neutrino mass hierarchy.
Dark Matter and neutrino masses from global U(1) B - L symmetry breaking
NASA Astrophysics Data System (ADS)
Lindner, Manfred; Schmidt, Daniel; Schwetz, Thomas
2011-11-01
We present a scenario where neutrino masses and Dark Matter are related due to a global U(1) B - L symmetry. Specifically we consider neutrino mass generation via the Zee-Babu two-loop mechanism, augmented by a scalar singlet whose VEV breaks the global U(1) B - L symmetry. In order to obtain a Dark Matter candidate we introduce two Standard Model singlet fermions. They form a Dirac particle and are stable because of a remnant Z2 symmetry. Hence, in this model the stability of Dark Matter follows from the global U(1) B - L symmetry. We discuss the Dark Matter phenomenology of the model, and compare it to similar models based on gauged U(1) B - L. We argue that in contrast to the gauged versions, the model based on the global symmetry does not suffer from severe constraints from Z‧ searches.
Neutrinos Masses in a Multi-Higgs Model with A4 symmetry
NASA Astrophysics Data System (ADS)
Machado, A. C. B.; Montero, J. C.; Pleitez, V.
2012-08-01
Presently it is well known that neutrino oscillation data are well described by massive neutrinos and their mixing. This suggests changes in the standard model (SM) and makes the flavor physics even more interesting. Recently, it has been proposed a multi-Higgs extension of the SM with Abelian and non-Abelian discrete symmetries which seeks to explain the origin of the masses and mixing matrices in all charge sectors.
A review of μ-τ flavor symmetry in neutrino physics
NASA Astrophysics Data System (ADS)
Xing, Zhi-Zhong; Zhao, Zhen-Hua
2016-07-01
Behind the observed pattern of lepton flavor mixing is a partial or approximate μ-τ flavor symmetry—a milestone on our road to the true origin of neutrino masses and flavor structures. In this review article we first describe the features of μ-τ permutation and reflection symmetries, and then explore their various consequences on model building and neutrino phenomenology. We pay particular attention to soft μ-τ symmetry breaking, which is crucial for our deeper understanding of the fine effects of flavor mixing and CP violation.
NASA Astrophysics Data System (ADS)
Aranda, Alfredo; Peinado, Eduardo
2016-03-01
A new realization for radiative neutrino mass generation is presented. Based on the requirement of tree-level custodial symmetry and the introduction of higher (greater than two) dimensional representations for scalar fields, a specific scenario with a scalar septet is presented that generates neutrino Majorana masses radiatively. This is accomplished through an eleven dimensional operator that requires the addition of several scalar fields and a SU(2) 5-plet of new fermions, together with a Z2 that guarantees the preservation of custodial symmetry. The phenomenology of the setup is rather rich and includes a dark matter candidate.
Sterile neutrinos for warm dark matter and the reactor anomaly in flavor symmetry models
Barry, James; Rodejohann, Werner; Zhang, He E-mail: werner.rodejohann@mpi-hd.mpg.de
2012-01-01
We construct a flavor symmetry model based on the tetrahedral group A{sub 4} in which the right-handed neutrinos from the seesaw mechanism can be both keV warm dark matter particles and eV-scale sterile neutrinos. This is achieved by giving the right-handed neutrinos appropriate charges under the same Froggatt-Nielsen symmetry responsible for the hierarchy of the charged lepton masses. We discuss the effect of next-to-leading order corrections to deviate the zeroth order tri-bimaximal mixing. Those corrections have two sources: (i) higher order seesaw terms, which are important when the seesaw particles are eV-scale, and (ii) higher-dimensional effective operators suppressed by additional powers of the cut-off scale of the theory. Whereas the mixing angles of the active neutrinos typically receive corrections of the same order, the mixing of the sterile neutrinos with the active ones is rather stable as it is connected with a hierarchy of mass scales. We also modify an effective A{sub 4} model to incorporate keV-scale sterile neutrinos.
Neutrino mixing and masses in SO(10) GUTs with hidden sector and flavor symmetries
NASA Astrophysics Data System (ADS)
Chu, Xiaoyong; Smirnov, Alexei Yu.
2016-05-01
We consider the neutrino masses and mixing in the framework of SO(10) GUTs with hidden sector consisting of fermionic and bosonic SO(10) singlets and flavor symmetries. The framework allows to disentangle the CKM physics responsible for the CKM mixing and different mass hierarchies of quarks and leptons and the neutrino new physics which produces smallness of neutrino masses and large lepton mixing. The framework leads naturally to the relation U PMNS ˜ V CKM † U 0, where structure of U 0 is determined by the flavor symmetry. The key feature of the framework is that apart from the Dirac mass matrices m D , the portal mass matrix M D and the mass matrix of singlets M S are also involved in generation of the lepton mixing. This opens up new possibilities to realize the flavor symmetries and explain the data. Using A 4 × Z 4 as the flavor group, we systematically explore the flavor structures which can be obtained in this framework depending on field content and symmetry assignments. We formulate additional conditions which lead to U 0 ˜ U TBM or U BM. They include (i) equality (in general, proportionality) of the singlet flavons couplings, (ii) equality of their VEVs; (iii) correlation between VEVs of singlets and triplet, (iv) certain VEV alignment of flavon triplet(s). These features can follow from additional symmetries or be remnants of further unification. Phenomenologically viable schemes with minimal flavon content and minimal number of couplings are constructed.
Flavour, electroweak symmetry breaking and dark matter: state of the art and future prospects
NASA Astrophysics Data System (ADS)
Ricciardi, Giulia; Arbey, Alexandre; Bertuzzo, Enrico; Carmona, Adrián; Dermíšek, Radovan; Huber, Tobias; Hurth, Tobias; Grossman, Yuval; Kersten, Jörn; Lunghi, Enrico; Mahmoudi, Farvah; Masiero, Antonio; Neubert, Matthias; Shepherd, William; Velasco-Sevilla, Liliana
2015-10-01
With the discovery of the Higgs boson the Standard Model has become a complete and comprehensive theory, which has been verified with unparalleled precision and in principle might be valid at all scales. However, several reasons remain why we firmly believe that there should be physics beyond the Standard Model. Experiments such as the LHC, new B factories, and earth- and space-based astro-particle experiments provide us with unique opportunities to discover a coherent framework for many of the long-standing puzzles of our field. Here we explore several significant interconnections between the physics of the Higgs boson, the physics of flavour, and the experimental clues we have about dark matter.
Dark matter, {mu} problem, and neutrino mass with gauged R symmetry
Choi, Ki-Young; Chun, Eung Jin; Lee, Hyun Min
2010-11-15
We show that the {mu} problem and the strong CP problem can be resolved in the context of the gauged U(1){sub R} symmetry, realizing an automatic Peccei-Quinn symmetry. In this scheme, right-handed neutrinos can be introduced to explain small Majorana or Dirac neutrino mass. The U(1){sub R} D-term mediated supersymmetry (SUSY) breaking, called the U(1){sub R} mediation, gives rise to a specific form of the flavor-conserving superpartner masses. For the given solution to the {mu} problem, electroweak symmetry breaking condition requires the superpartners of the standard model at low energy to be much heavier than the gravitino. Thus, the dark matter candidate can be either gravitino or right-handed sneutrino. In the Majorana neutrino case, only gravitino is a natural dark matter candidate. On the other hand, in the Dirac neutrino case, the right-handed sneutrino can be also a dark matter candidate as it gets mass only from SUSY breaking. We discuss the non-thermal production of our dark matter candidates from the late decay of stau and find that the constraints from the big bang nucleosynthesis can be evaded for a TeV-scale stau mass.
Two loop neutrino model and dark matter particles with global B−L symmetry
Baek, Seungwon; Okada, Hiroshi; Toma, Takashi E-mail: hokada@kias.re.kr
2014-06-01
We study a two loop induced seesaw model with global U(1){sub B−L} symmetry, in which we consider two component dark matter particles. The dark matter properties are investigated together with some phenomenological constraints such as electroweak precision test, neutrino masses and mixing and lepton flavor violation. In particular, the mixing angle between the Standard Model like Higgs and an extra Higgs is extremely restricted by the direct detection experiment of dark matter. We also discuss the contribution of Goldstone boson to the effective number of neutrino species ΔN{sub eff} ≈ 0.39 which has been reported by several experiments.
Soft A4→Z3 symmetry breaking and cobimaximal neutrino mixing
Ma, Ernest
2016-03-28
In this study, I propose a model of radiative charged-lepton and neutrino masses with A4 symmetry. The soft breaking of A4 to Z3 lepton triality is accomplished by dimension-three terms. The breaking of Z3 by dimension-two terms allows cobimaximal neutrino mixing (θ13 ≠ 0, θ23 = π/4, δcp=π/2) to be realized with only very small finite calculable deviations from the residual Z3 lepton triality. This construction solves a long-standing technical problem inherent in renormalizable A4 models since their inception.
Dirac neutrinos with S4 flavor symmetry in warped extra dimensions
NASA Astrophysics Data System (ADS)
Ding, Gui-Jun; Zhou, Ye-Ling
2013-11-01
We present a warped extra dimension model with the custodial symmetry SU(2×SU(2×U(1×PLR based on the flavor symmetry S4×Z2×Z2', and the neutrinos are taken to be Dirac particles. At leading order, the democratic lepton mixing is derived exactly, and the high-dimensional operators introduce corrections of order λc to all the three lepton mixing angles such that agreement with the experimental data can be achieved. The neutrino mass spectrum is predicted to be of the inverted hierarchy and the second octant of θ23 is preferred. We suggest the modified democratic mixing, which is obtained by permuting the second and the third rows of the democratic mixing matrix, should be a good first order approximation to understanding sizable θ13 and the first octant of θ23. The constraints on the model from the electroweak precision measurements are discussed. Furthermore, we investigate the lepton mixing patterns for all the possible residual symmetries Gν and Gl in the neutrino and charged lepton sectors, respectively. For convenience, we work in the base in which m≡mlml† is diagonal, where ml is the charged lepton mass matrix. It is easy to see that the symmetry transformation matrix Gl, which is determined by the condition Gl†mGl=m, is a diagonal and non-degenerate 3×3 phase matrix. In the case that neutrinos are Majorana particles, the light neutrino mass matrix for DC mixing is of the form mνDC=UDC*diag(m1,m2,m3)UDC†. The symmetry transformations Gi, which satisfy GiTmνDCGi=mνDC, are determined to be G1=+u1u1†-u2u2†-u3u3†, G2=-u1u1†+u2u2†-u3u3† and G3=-u1u1†-u2u2†+u3u3† besides the identity transformation, where ui is the ith column of UDC. They satisfy Gi2=1, GiGj=GjGi=Gk(i≠j≠k). Consequently the symmetry group of the neutrino mass matrix mνDC is the Klein four group K4≅Z2×Z2. Denoting the underlying family symmetry group at high energies as G, then the symmetry transformations Gl and Gi should be the elements of G. In the
Residual Symmetries Applied to Neutrino Oscillations at NO ν A and T2K
Hanlon, Andrew D.; Repko, Wayne W.; Dicus, Duane A.
2014-01-01
Tmore » he results previously obtained from the model-independent application of a generalized hidden horizontal Z 2 symmetry to the neutrino mass matrix are updated using the latest global fits for the neutrino oscillation parameters.he resulting prediction for the Dirac CP phase δ D is in agreement with recent results from2K.he distribution for the Jarlskog invariant J ν has become sharper and appears to be approaching a particular region.he approximate effects of matter on long-baseline neutrino experiments are explored, and it is shown how the weak interactions between the neutrinos and the particles that make up the Earth can help to determine the mass hierarchy. A similar strategy is employed to show how NO ν A and2K could determine the octant of θ a ( ≡ θ 23 ) . Finally, the exact effects of matter are obtained numerically in order to make comparisons with the form of the approximate solutions. From this analysis there emerge some interesting features of the effective mass eigenvalues.« less
Dynamical electroweak symmetry breaking in the model of electroweak-scale right-handed neutrinos
NASA Astrophysics Data System (ADS)
Hung, Pham Quang; Le, Nguyen Nhu
2016-04-01
We present the Higgs mechanism in the context of the EW-scale νR model in which electroweak symmetry is dynamically broken by condensates of mirror quark and right-handed neutrino through the exchange of one fundamental Higgs doublet and one fundamental Higgs triplet, respectively. The formation of these condensates is dynamically investigated by using the Schwinger-Dyson approach. The occurrence of these condensates will give rise to the rich Higgs spectrum. In addition, the VEVs of Higgs fields is also discussed in this dynamical phenomenon.
A three-loop neutrino model with global U (1) symmetry
NASA Astrophysics Data System (ADS)
Hatanaka, Hisaki; Nishiwaki, Kenji; Okada, Hiroshi; Orikasa, Yuta
2015-05-01
We study a three-loop induced neutrino model with a global U (1) symmetry at TeV scale, in which we naturally accommodate a bosonic dark matter candidate. We discuss the allowed regions of masses and quartic couplings for charged scalar bosons as well as the dark matter mass on the analogy of the original Zee-Babu model, and show the difference between them. We also discuss that the possibility of the collider searches in a future like-sign electron liner collider could be promising.
Models of neutrino mass, mixing and CP violation
NASA Astrophysics Data System (ADS)
King, Stephen F.
2015-12-01
In this topical review we argue that neutrino mass and mixing data motivates extending the Standard Model (SM) to include a non-Abelian discrete flavour symmetry in order to accurately predict the large leptonic mixing angles and {C}{P} violation. We begin with an overview of the SM puzzles, followed by a description of some classic lepton mixing patterns. Lepton mixing may be regarded as a deviation from tri-bimaximal mixing, with charged lepton corrections leading to solar mixing sum rules, or tri-maximal lepton mixing leading to atmospheric mixing rules. We survey neutrino mass models, using a roadmap based on the open questions in neutrino physics. We then focus on the seesaw mechanism with right-handed neutrinos, where sequential dominance (SD) can account for large lepton mixing angles and {C}{P} violation, with precise predictions emerging from constrained SD (CSD). We define the flavour problem and discuss progress towards a theory of favour using GUTs and discrete family symmetry. We classify models as direct, semidirect or indirect, according to the relation between the Klein symmetry of the mass matrices and the discrete family symmetry, in all cases focussing on spontaneous {C}{P} violation. Finally we give two examples of realistic and highly predictive indirect models with CSD, namely an A to Z of flavour with Pati-Salam and a fairly complete A 4 × SU(5) SUSY GUT of flavour, where both models have interesting implications for leptogenesis.
Nonzero θ13 for neutrino mixing in a supersymmetric B-L gauge model with T7 lepton flavor symmetry
NASA Astrophysics Data System (ADS)
Cao, Qing-Hong; Khalil, Shaaban; Ma, Ernest; Okada, Hiroshi
2011-10-01
We discuss how θ13≠0 is accommodated in a recently proposed renormalizable model of neutrino mixing using the non-Abelian discrete symmetry T7 in the context of a supersymmetric extension of the standard model with gauged U(1)B-L. We predict a correlation between θ13 and θ23, as well as the effective neutrino mass mee in neutrinoless double beta decay.
Neutrino mass and mixing in the 3-3-1 model with neutral leptons based on D4 flavor symmetry
NASA Astrophysics Data System (ADS)
Vien, V. V.
2014-07-01
We propose a new D4 flavor model based on SU(3)C⊗SU(3)L ⊗U(1)X gauge symmetry responsible for fermion masses and mixings in which all fermion fields act only as singlets under D4 which differs from our previous work. The neutrinos get small masses from two SU(3)L anti-sextets and one SU(3)L triplet which are all in singlets under D4. If a SU(3)L Higgs triplet, lying in {1}''' under D4, is considered as a perturbation the corresponding neutrino mass mixing matrix gets the most general form. In this case, the model can fit the most recent data on neutrino masses and mixing with nonzero θ13. Our results show that the neutrino masses are naturally small. The sum of three light neutrino masses and the effective mass governing neutrinoless double beta decay are obtained that are consistent with the recent data.
U(1)B-L symmetry restoration and effective neutrino species
NASA Astrophysics Data System (ADS)
Ishida, Hiroyuki; Takahashi, Fuminobu
2014-06-01
The U(1)B-L symmetry could be restored during inflation, since the BICEP2 results suggest a GUT-scale inflation with the Hubble parameter, Hinf≃1014 GeV, close to the U(1)B-L breaking scale. We consider a scenario in which the B-L Higgs field dominates the Universe after inflation, and mainly decays into the U(1)B-L gauge bosons, whose subsequent decays reheat the Universe. Interestingly, if one of the right-handed neutrinos is extremely light and behaves as dark radiation or hot dark matter, its abundance is determined by the B-L charge assignment and the relativistic degree of freedom in plasma. We find that ΔNeff takes discrete values between 0.188 and 0.220 in the standard model plus three right-handed neutrinos, depending on whether the decay into heavier right-handed neutrinos is kinematically accessible or not. In the fiveness U(1)5 case, we find that ΔNeff takes discrete values between 0.313 and 0.423. The tension between BICEP2 and Planck can be partially relaxed by dark radiation.
Recent neutrino data and type III seesaw model with discrete symmetry
NASA Astrophysics Data System (ADS)
Ahn, Y. H.; Kim, C. S.; Oh, Sechul
2012-07-01
In light of the recent neutrino experiment results from the Daya Bay and RENO Collaborations, we study phenomenology of neutrino mixing angles in the type III seesaw model with a discrete A4×Z2 symmetry, whose spontaneously breaking scale is much higher than the electroweak scale. At tree level, the tri-bimaximal (TBM) form of the lepton mixing matrix can be obtained from leptonic Yukawa interactions in a natural way. We introduce all possible effective dimension-five operators, invariant under the standard model gauge group and A4×Z2, and explicitly show that they induce a deviation of the lepton mixing from the TBM mixing matrix, which can explain a large mixing angle θ13 together with small deviations of the solar and atmospheric mixing angles from the TBM. Two possible scenarios are investigated, by taking into account either negligible or sizable contributions from the light charged lepton sector to the lepton mixing matrix. Especially it is found in the latter scenario that all the neutrino experimental data, including the recent best-fit value of θ13=8.68°, can be accommodated. The leptonic CP violation characterized by the Jarlskog invariant JCP has a nonvanishing value, indicating a signal of maximal CP violation.
Quantum resonant leptogenesis and minimal lepton flavour violation
Cirigliano, Vincenzo; De Simone, Andrea; Isidori, Gino; Masina, Isabella; Riotto, Antonio E-mail: andreads@mit.edu E-mail: imasina@mail.cern.ch
2008-01-15
It has recently been shown that the quantum Boltzmann equations may be relevant for the leptogenesis scenario. In particular, they lead to a time-dependent CP asymmetry which depends upon the previous dynamics of the system. This memory effect in the CP asymmetry is particularly important in resonant leptogenesis where the asymmetry is generated by the decays of nearly mass-degenerate right-handed neutrinos. We study the impact of the non-trivial time evolution of the CP asymmetry in the so-called minimal lepton flavour violation framework where the charged-lepton and the neutrino Yukawa couplings are the only irreducible sources of lepton flavour symmetry breaking and resonant leptogenesis is achieved. We show that significant quantitative differences arise with respect to the case in which the time dependence of the CP asymmetry is neglected.
Field, J.H. . E-mail: john.field@cern.ch
2006-03-15
Feynman's laws of quantum dynamics are concisely stated, discussed in comparison with other formulations of quantum mechanics and applied to selected problems in the physical optics of photons and massive particles as well as flavour oscillations. The classical wave theory of light is derived from these laws for the case in which temporal variation of path amplitudes may be neglected, whereas specific experiments, sensitive to the temporal properties of path amplitudes, are suggested. The reflection coefficient of light from the surface of a transparent medium is found to be markedly different to that predicted by the classical Fresnel formula. Except for neutrino oscillations, good agreement is otherwise found with previous calculations of spatially dependent quantum interference effects.
The role of flavon cross couplings in leptonic flavour mixing
NASA Astrophysics Data System (ADS)
Pascoli, Silvia; Zhou, Ye-Ling
2016-06-01
In models with discrete flavour symmetries, flavons are critical to realise specific flavour structures. Leptonic flavour mixing originates from the misalignment of flavon vacuum expectation values which respect different residual symmetries in the charged lepton and neutrino sectors. Flavon cross couplings are usually forbidden, in order to protect these symmetries. Contrary to this approach, we show that cross couplings can play a key role and give raise to necessary corrections to flavour-mixing patterns, including a non-zero value for the reactor angle and CP violation. For definiteness, we present two models based on A 4. In the first model, all flavons are assumed to be real or pseudo-real, with 7 real degrees of freedom in the flavon sector in total. A sizable reactor angle associated with nearly maximal CP violation is achieved, and, as both originate from the same cross coupling, a sum rule results with a precise prediction for the value of the Dirac CP-violating phase. In the second model, the flavons are taken to be complex scalars, which can be connected with supersymmetric models and multi-Higgs models. The complexity properties of flavons provide new sources for generating the reactor angle. Models in this new approach introduce very few degrees of freedom beyond the Standard Model and can be more economical than those in the framework of extra dimension or supersymmetry.
A 3-3-1 model with right-handed neutrinos based on the Δ ( 27) family symmetry
NASA Astrophysics Data System (ADS)
Hernández, A. E. Cárcamo; Long, H. N.; Vien, V. V.
2016-05-01
We present the first multiscalar singlet extension of the original 3-3-1 model with right-handed neutrinos, based on the Δ ( 27) family symmetry, supplemented by the Z4⊗ Z8⊗ Z_{14} flavor group, consistent with current low energy fermion flavor data. In the model under consideration, the light active neutrino masses are generated from a double seesaw mechanism and the observed pattern of charged fermion masses and quark mixing angles is caused by the breaking of the Δ ( 27) ⊗ Z4⊗ Z8⊗ Z_{14} discrete group at very high energy. Our model has only 14 effective free parameters, which are fitted to reproduce the experimental values of the 18 physical observables in the quark and lepton sectors. The obtained physical observables for the quark sector agree with their experimental values, whereas those for the lepton sector also do, only for the inverted neutrino mass hierarchy. The normal neutrino mass hierarchy scenario of the model is disfavored by the neutrino oscillation experimental data. We find an effective Majorana neutrino mass parameter of neutrinoless double beta decay of m_{β β }= 22 meV, a leptonic Dirac CP violating phase of 34°, and a Jarlskog invariant of about 10^{-2} for the inverted neutrino mass spectrum.
Ultra-high energy neutrino fluxes as a probe for non-standard physics
Bhattacharya, Atri; Choubey, Sandhya; Gandhi, Raj; Watanabe, Atsushi E-mail: sandhya@hri.res.in E-mail: watanabe@muse.sc.niigata-u.ac.jp
2010-09-01
We examine how light neutrinos coming from distant active galactic nuclei (AGN) and similar high energy sources may be used as tools to probe non-standard physics. In particular we discuss how studying the energy spectra of each neutrino flavour coming from such distant sources and their distortion relative to each other may serve as pointers to exotic physics such as neutrino decay, Lorentz symmetry violation, pseudo-Dirac effects, CP and CPT violation and quantum decoherence. This allows us to probe hitherto unexplored ranges of parameters for the above cases, for example lifetimes in the range 10{sup −3}−10{sup 4} s/eV for the case of neutrino decay. We show that standard neutrino oscillations ensure that the different flavours arrive at the earth with similar shapes even if their flavour spectra at source may differ strongly in both shape and magnitude. As a result, observed differences between the spectra of various flavours at the detector would be signatures of non-standard physics altering neutrino fluxes during propagation rather than those arising during their production at source. Since detection of ultra-high energy (UHE) neutrinos is perhaps imminent, it is possible that such differences in spectral shapes will be tested in neutrino detectors in the near future. To that end, using the IceCube detector as an example, we show how our results translate to observable shower and muon-track event rates.
Approaching Minimal Flavour Violation from an SU(5) × S 4 × U(1) SUSY GUT
NASA Astrophysics Data System (ADS)
Dimou, Maria; King, Stephen F.; Luhn, Christoph
2016-02-01
We show how approximate Minimal Flavour Violation (MFV) can emerge from an SU(5) Supersymmetric Grand Unified Theory (SUSY GUT) supplemented by an S 4 × U(1) family symmetry, which provides a good description of all quark and lepton (including neutrino) masses, mixings and CP violation. Assuming a SUSY breaking mechanism which respects the family symmetry, we calculate in full explicit detail the low energy mass insertion parameters in the super-CKM basis, including the effects of canonical normalisation and renormalisation group running. We find that the very simple family symmetry S 4 ×U(1) is sufficient to approximately reproduce the effects of low energy MFV.
NASA Astrophysics Data System (ADS)
Bergström, L.; Hulth, P. O.; Botner, O.; Carlson, P.; Ohlsson, T.
2006-03-01
J. N. Bahcall (1934-2005) -- Preface -- List of participants -- Committees -- Nobel symposium on neutrino physics - program -- The history of neutrino oscillations / S. M. Bilenky -- Super-Kamiokande results on neutrino oscillations / Y. Suzuki -- Sudbury neutrino observatory results / A. B. McDonald -- Results from KamLAND reactor neutrino detection / A. Suzuki -- New opportunities for surprise / J. Conrad -- Solar models and solar neutrinos / J. N. Bahcall -- Atmospheric neutrino fluxes / T. K. Gaisser -- The MSW effect and matter effects in neutrino oscillations / A. Yu. Smirnov -- Three-flavour effects and CP- and T-violation in neutrino oscillations / E. Kh. Akhmedov -- Global analysis of neutrino data / M. C. Gonzalez-Garcia -- Future precision neutrino oscillation experiments and theoretical implications / M. Lindner -- Experimental prospects of neutrinoless double beta decay / E. Fiorini -- Theoretical prospects of neutrinoless double beta decay / S. T. Petcov -- Supernova neutrino oscillations / G. G. Raffelt -- High-energy neutrino astronomy / F. Halzen -- Neutrino astrophysics in the cold: Amanda, Baikal and IceCube / C. Spiering -- Status of radio and acoustic detection of ultra-high energy cosmic neutrinos and a proposal on reporting results / D. Saltzberg -- Detection of neutrino-induced air showers / A. A. Watson -- Prospect for relic neutrino searches / G. B. Gelmini -- Leptogenesis in the early universe / T. Yanagida -- Neutrinos and big bang nucleosynthesis / G. Steigman -- Extra galactic sources of high energy neutrinos / E. Waxman -- Cosmological neutrino bounds for non-cosmologists / M. Tegmark -- Neutrino intrinsic properties: the neutrino-antineutrino relation / B. Kayser -- NuTeV and neutrino properties / M. H. Shaevitz -- Absolute masses of neutrinos - experimental results and future possibilities / C. Weinheimer -- Flavor theories and neutrino masses / P. Ramond -- Neutrino mass models and leptogenesis / S. F. King -- Neutrino mass and
NASA Astrophysics Data System (ADS)
Samanta, Rome; Chakraborty, Mainak; Ghosal, Ambar
2016-03-01
We evaluate the Majorana phases for a general 3 × 3 complex symmetric neutrino mass matrix on the basis of Mohapatra-Rodejohann's phase convention using the three rephasing invariant quantities I12, I13 and I23 proposed by Sarkar and Singh. We find them interesting as they allow us to evaluate each Majorana phase in a model independent way even if one eigenvalue is zero. Utilizing the solution of a general complex symmetric mass matrix for eigenvalues and mixing angles we determine the Majorana phases for both the hierarchies, normal and inverted, taking into account the constraints from neutrino oscillation global fit data as well as bound on the sum of the three light neutrino masses (Σimi) and the neutrinoless double beta decay (ββ0ν) parameter |m11 |. This methodology of finding the Majorana phases is applied thereafter in some predictive models for both the hierarchical cases (normal and inverted) to evaluate the corresponding Majorana phases and it is shown that all the sub cases presented in inverted hierarchy section can be realized in a model with texture zeros and scaling ansatz within the framework of inverse seesaw although one of the sub cases following the normal hierarchy is yet to be established. Except the case of quasi degenerate neutrinos, the methodology obtained in this work is able to evaluate the corresponding Majorana phases, given any model of neutrino masses.
The Mystery of Neutrino Mixings
NASA Astrophysics Data System (ADS)
Altarelli, Guido
2013-07-01
In the last years we have learnt a lot about neutrino masses and mixings. Neutrinos are not all massless but their masses are very small. Probably masses are small because neutrinos are Majorana particles with masses inversely proportional to the large scale M of lepton number (L) violation, which turns out to be compatible with the GUT scale. We have understood that there is no contradiction between large neutrino mixings and small quark mixings, even in the context of GUTs and that neutrino masses fit well in the SUSY GUT picture. Out of equilibrium decays with CP and L violation of heavy RH neutrinos can produce a B-L asymmetry, then converted near the weak scale by instantons into an amount of B asymmetry compatible with observations (baryogenesis via leptogenesis). It appears that active neutrinos are not a significant component of Dark Matter in the Universe. A long list of models have been formulated over the years to understand neutrino masses and mixings. With the continuous improvement of the data most of the models have been discarded by experiment. The surviving models still span a wide range going from a maximum of symmetry, with discrete non-abelian flavour groups, to the opposite extreme of anarchy.
Zavala, I.
2008-11-23
A new class of particle physics models of inflation based on the phase transition associated with the spontaneous breaking of family symmetry is proposed. The Higgs fields responsible for the breaking of family symmetry, the flavons, are natural inflaton candidates or waterfall fields in hybrid inflation. This opens up a rich vein of possible inflation models, all linked to the physics of flavour, with several interesting cosmological implications.
Westhoff, Susanne
2010-02-10
We probe the unification of down quarks and leptons in a supersymmetric SO(10) GUT. The large atmospheric neutrino mixing angle induces b{sub R}-s{sub R} transitions, which can account for the sizeable CP phase oe{sub s} measured in B{sub s}-B{sub s} mixing. Corrections to down-quark-lepton unification from higher-dimensional Yukawa terms translate neutrino mixing also into s{sub R}-d{sub R} and b{sub R}-d{sub R} currents. We find the flavour structure of Yukawa corrections to be strongly constrained by epsilon{sub K}.
Besson, Dave; Cowen, Doug; Selen, Mats; Wiebusch, Christopher
1999-01-01
Neutrinos represent a new “window” to the Universe, spanning a large range of energy. We discuss the science of neutrino astrophysics and focus on two energy regimes. At “lower” energies (≈1 MeV), studies of neutrinos born inside the sun, or produced in interactions of cosmic rays with the atmosphere, have allowed the first incontrovertible evidence that neutrinos have mass. At energies typically one thousand to one million times higher, sources further than the sun (both within the Milky Way and beyond) are expected to produce a flux of particles that can be detected only through neutrinos. PMID:10588680
CP phases of neutrino mixing in a supersymmetric B-L gauge model with T7 lepton flavor symmetry
NASA Astrophysics Data System (ADS)
Ishimori, Hajime; Khalil, Shaaban; Ma, Ernest
2012-07-01
In a recently proposed renormalizable model of neutrino mixing using the non-Abelian discrete symmetry T7 in the context of a supersymmetric extension of the standard model with gauged U(1)B-L, a correlation was obtained between θ13 and θ23 in the case where all four parameters are real. Here we consider one parameter to be complex, thus allowing for one Dirac CP phase δCP and two Majorana CP phases α1,2. We find a slight modification to this correlation as a function of δCP. For a given set of input values of Δm212, Δm322, θ12, and θ13, we obtain sin22θ23 and mee (the effective Majorana neutrino mass in neutrinoless double beta decay) as functions of tanδCP. We find that the structure of this model always yields small |tanδCP|.
Aspects of neutrino oscillation in alternative gravity theories
Chakraborty, Sumanta
2015-10-01
Neutrino spin and flavour oscillation in curved spacetime have been studied for the most general static spherically symmetric configuration. Having exploited the spherical symmetry we have confined ourselves to the equatorial plane in order to determine the spin and flavour oscillation frequency in this general set-up. Using the symmetry properties we have derived spin oscillation frequency for neutrino moving along a geodesic or in a circular orbit. Starting from the expression of neutrino spin oscillation frequency we have shown that even in this general context, in high energy limit the spin oscillation frequency for neutrino moving along circular orbit vanishes. We have verified previous results along this line by transforming to Schwarzschild coordinates under appropriate limit. This finally lends itself to the probability of neutrino helicity flip which turns out to be non-zero. While for neutrino flavour oscillation we have derived general results for oscillation phase, which subsequently have been applied to three different gravity theories. One, of them appears as low-energy approximation to string theory, where we have an additional field, namely, dilaton field coupled to Maxwell field tensor. This yields a realization of Reissner-Nordström solution in string theory at low-energy. Next one corresponds to generalization of Schwarzschild solution by introduction of quadratic curvature terms of all possible form to the Einstein-Hilbert action. Finally, we have also discussed regular black hole solutions. In all these cases the flavour oscillation probabilities can be determined for solar neutrinos and thus can be used to put bounds on the parameters of these gravity theories. While for spin oscillation probability, we have considered two cases, Gauss-Bonnet term added to the Einstein-Hilbert action and the f(R) gravity theory. In both these cases we could impose bounds on the parameters which are consistent with previous considerations. In a nutshell, in
Flavour violation in general supergravity
NASA Astrophysics Data System (ADS)
Chankowski, Piotr H.; Lebedev, Oleg; Pokorski, Stefan
2005-06-01
We reappraise the flavour changing neutral currents (FCNC) problem in string-derived supergravity models. We overview and classify possible sources of flavour violation and find that the problem often does not arise in classes of models which generate hierarchical Yukawa matrices. In such models, constraints from the K- and D-meson systems leave room for substantial flavour non-universality of the soft terms. The current B-physics experiments only begin to probe its natural range. Correlations among different observables can allow one to read off the chirality structure of flavour violating sources. We briefly discuss the lepton sector where the problem of FCNC is indeed serious and perhaps points at an additional symmetry or flavour universality.
NASA Astrophysics Data System (ADS)
Vien, V. V.
2014-09-01
We construct a new version for the 3-3-1 model based on T7 flavor symmetry where the left-handed leptons under T7 differ from those of our previous work while the SU(3)C ⊗SU(3)L ⊗U(1)X gauge symmetry is retained. The flavor mixing patterns and mass splitting are obtained without perturbation. The realistic lepton mixing can be obtained if both the direction of breakings T7 →Z3 and Z3 →{Identity} are taken place in neutrino sector. Maximal CP violation is predicted and Cabibbo-Kobayashi-Maskawa (CKM) matrix is the identity matrix at the tree-level.
Cao Qinghong; Khalil, Shaaban; Ma, Ernest; Okada, Hiroshi
2011-10-01
We discuss how {theta}{sub 13}{ne}0 is accommodated in a recently proposed renormalizable model of neutrino mixing using the non-Abelian discrete symmetry T{sub 7} in the context of a supersymmetric extension of the standard model with gauged U(1){sub B-L}. We predict a correlation between {theta}{sub 13} and {theta}{sub 23}, as well as the effective neutrino mass m{sub ee} in neutrinoless double beta decay.
Neutrino Oscillations and the Sudbury Neutrino Observatory
NASA Astrophysics Data System (ADS)
Wark, David
2001-04-01
When the existence of the neutrino was almost apologetically first proposed by Wolfgang Pauli it was intended to explain the mysterious apparent absence of energy and momentum in beta decay. 70 years later the neutrino has indeed solved that mystery, but it has generated still more of its own. Are neutrinos massive? Is it possible to create a neutrino with its spin in the same direction as its momentum? What fraction of the mass of the Universe is made up of neutrinos? Are the flavour labels which we put on neutrinos, like electron and muon, really fixed or can they change? Why does no experiment see the predicted flux of neutrinos from the Sun? Why do there appear to be roughly equal numbers of muon and electron neutrinos created in our atmosphere, rather than the 2:1 ratio we would expect? Many of these questions were coupled when Bruno Pontecorvo first suggested that the shortfall in solar neutrino measurements were caused by neutrino oscillations - neutrinos spontaneously changing flavour as they travel from the Sun. 30 years later we still await definitive proof of that conjecture, and providing that proof is the reason for the Sudbury Neutrino Observatory. The talk will discuss the current state of neutrino oscillations studies, and show how the unique capabilities of the Sudbury Neutrino Observatory can provide definitive proof of whether neutrino oscillations are the long-sought answer to the solar neutrino problem.
Neutrino mixing with nonzero θ13 and CP violation in the 3-3-1 model based on A4 flavor symmetry
NASA Astrophysics Data System (ADS)
Vien, Vo Van; Long, Hoang Ngoc
2015-07-01
We propose a 3-3-1 model with neutral fermions based on A4 flavor symmetry responsible for fermion masses and mixings with nonzero θ13. To get realistic neutrino mixing, we just add a new SU(3)L triplet being in 3̲ under A4. The neutrinos get small masses from two SU(3)L antisextets and one SU(3)L triplet. The model can fit the present data on neutrino masses and mixing as well as the effective mass governing neutrinoless double beta decay. Our results show that the neutrino masses are naturally small and a little deviation from the tri-bimaximal neutrino mixing form can be realized. The Dirac CP violation phase δ is predicted to either 5.41∘ or 354.59∘ with θ23≠π 4.
Testing constrained sequential dominance models of neutrinos
NASA Astrophysics Data System (ADS)
Björkeroth, Fredrik; King, Stephen F.
2015-12-01
Constrained sequential dominance (CSD) is a natural framework for implementing the see-saw mechanism of neutrino masses which allows the mixing angles and phases to be accurately predicted in terms of relatively few input parameters. We analyze a class of CSD(n) models where, in the flavour basis, two right-handed neutrinos are dominantly responsible for the ‘atmospheric’ and ‘solar’ neutrino masses with Yukawa couplings to ({ν }e,{ν }μ ,{ν }τ ) proportional to (0,1,1) and (1,n,n-2), respectively, where n is a positive integer. These coupling patterns may arise in indirect family symmetry models based on A 4. With two right-handed neutrinos, using a χ 2 test, we find a good agreement with data for CSD(3) and CSD(4) where the entire Pontecorvo-Maki-Nakagawa-Sakata mixing matrix is controlled by a single phase η, which takes simple values, leading to accurate predictions for mixing angles and the magnitude of the oscillation phase | {δ }{CP}| . We carefully study the perturbing effect of a third ‘decoupled’ right-handed neutrino, leading to a bound on the lightest physical neutrino mass {m}1{{≲ }}1 meV for the viable cases, corresponding to a normal neutrino mass hierarchy. We also discuss a direct link between the oscillation phase {δ }{CP} and leptogenesis in CSD(n) due to the same see-saw phase η appearing in both the neutrino mass matrix and leptogenesis.
Deviations from tribimaximal neutrino mixing using a model with Δ(27) symmetry
NASA Astrophysics Data System (ADS)
Harrison, P. F.; Krishnan, R.; Scott, W. G.
2014-07-01
We present a model of neutrino mixing based on the flavor group Δ(27) in order to account for the observation of a nonzero reactor mixing angle (θ13). The model provides a common flavor structure for the charged-lepton and the neutrino sectors, giving their mass matrices a "circulant-plus-diagonal" form. Mass matrices of this form readily lead to mixing patterns with realistic deviations from tribimaximal mixing, including nonzero θ13. With the parameters constrained by existing measurements, our model predicts an inverted neutrino mass hierarchy. We obtain two distinct sets of solutions in which the atmospheric mixing angle lies in the first and the second octants. The first (second) octant solution predicts the lightest neutrino mass, m3 29 meV(m3 65 meV) and the CP phase, δ CP ˜-(π )/(4) (δ CP ˜(π )/(2)), offering the possibility of large observable CP violating effects in future experiments.
Neutrino mixing with nonzero θ13 and CP violation in the 3-3-1 model based on S4 flavor symmetry
NASA Astrophysics Data System (ADS)
Vien, Vo Van; Long, Hoang Ngoc; Khoi, Dinh Phan
2015-06-01
The 3-3-1 model proposed in 2011 based on discrete symmetry S4 responsible for the neutrino and quark masses is updated, in which the nonzero θ13 is focused. Neutrino masses and mixings are consistent with the most recent data on neutrino oscillations without perturbation. The new feature is adding a new SU(3)L anti-sextet lying in doublet under S4 which can result the nonzero θ13 without perturbation, and consequently, the number of Higgs multiplets required is less than those of other models based on non-Abelian discrete symmetries and the 3-3-1 models. The exact tribimaximal form obtained with the breaking S4 → Z3 in charged lepton sector and S4 →𝒦 in neutrino sector. If both breakings S4 →𝒦 and 𝒦→ Z2 are taken place in neutrino sector, the realistic neutrino spectrum is obtained without perturbation. The upper bound on neutrino mass and the effective mass governing neutrinoless double beta decay at the tree level are presented. The model predicts the Dirac CP violation phase δ = 292.45° in the normal spectrum (with θ23≠π 4) and δ = 303.14° in the inverted spectrum.
Atmospheric neutrinos, ν e- ν s oscillations and a novel neutrino evolution equation
NASA Astrophysics Data System (ADS)
Akhmedov, Evgeny
2016-08-01
If a sterile neutrino ν s with an eV-scale mass and a sizeable mixing to the electron neutrino exists, as indicated by the reactor and gallium neutrino anomalies, a strong resonance enhancement of ν e -ν s oscillations of atmospheric neutrinos should occur in the TeV energy range. At these energies neutrino flavour transitions in the 3+1 scheme depend on just one neutrino mass squared difference and are fully described within a 3-flavour oscillation framework. We demonstrate that the flavour transitions of atmospheric ν e can actually be very accurately described in a 2-flavour framework, with neutrino flavour evolution governed by an inhomogeneous Schrödinger-like equation. Evolution equations of this type have not been previously considered in the theory of neutrino oscillations.
Davidson, Sacha
2008-02-21
Neutrinos can contribute to various episodes of the evolution of the Universe. For instance, in the seesaw model, they may generate the baryon asymmetry of the Universe via leptogenesis. This conference proceedings briefly reviews lepton flavour effects in thermal leptogenesis.
NASA Astrophysics Data System (ADS)
Mondal, Subhadeep; Rai, Santosh Kumar
2016-01-01
The breaking of parity, a fundamental symmetry between left and right, is best understood in the framework of left-right symmetric extension of the standard model. We show that the production of a heavy right-handed neutrino at the proposed Large Hadron-Electron Collider (LHeC) could give us the most simple and direct hint of the scale of this breaking in left-right symmetric theories. This production mode gives a lepton number violating signal with Δ L =2 which is very clean and has practically no standard model background. We highlight that the right-handed nature of WR exchange which defines the left-right symmetric theories can be confirmed by using a polarized electron beam and also enhance the production rates with relatively lower beam energy.
NASA Astrophysics Data System (ADS)
Winter, K.; Murdin, P.
2000-11-01
Neutrinos are electrically neutral ELEMENTARY PARTICLES which experience only the weak nuclear force and gravity. Their existence was introduced as a hypothesis by Wolfgang Pauli in 1930 to explain the apparent violation of energy conservation in radioactive beta decay. Chadwick had discovered in 1914 that the energy spectrum of electrons emitted in beta decay was not monoenergetic but continuous...
Two-Higgs-doublet models with Minimal Flavour Violation
Carlucci, Maria Valentina
2010-12-22
The tree-level flavour-changing neutral currents in the two-Higgs-doublet models can be suppressed by protecting the breaking of either flavour or flavour-blind symmetries, but only the first choice, implemented by the application of the Minimal Flavour Violation hypothesis, is stable under quantum corrections. Moreover, a two-Higgs-doublet model with Minimal Flavour Violation enriched with flavour-blind phases can explain the anomalies recently found in the {Delta}F = 2 transitions, namely the large CP-violating phase in B{sub s} mixing and the tension between {epsilon}{sub K} and S{sub {psi}KS}.
NASA Astrophysics Data System (ADS)
Müller, Bernhard; Janka, Hans-Thomas; Dimmelmeier, Harald
2010-07-01
We present a new general relativistic code for hydrodynamical supernova simulations with neutrino transport in spherical and azimuthal symmetry (one dimension and two dimensions, respectively). The code is a combination of the COCONUT hydro module, which is a Riemann-solver-based, high-resolution shock-capturing method, and the three-flavor, fully energy-dependent VERTEX scheme for the transport of massless neutrinos. VERTEX integrates the coupled neutrino energy and momentum equations with a variable Eddington factor closure computed from a model Boltzmann equation and uses the "ray-by-ray plus" approximation in two dimensions, assuming the neutrino distribution to be axially symmetric around the radial direction at every point in space, and thus the neutrino flux to be radial. Our spacetime treatment employs the Arnowitt-Deser-Misner 3+1 formalism with the conformal flatness condition for the spatial three metric. This approach is exact for the one-dimensional case and has previously been shown to yield very accurate results for spherical and rotational stellar core collapse. We introduce new formulations of the energy equation to improve total energy conservation in relativistic and Newtonian hydro simulations with grid-based Eulerian finite-volume codes. Moreover, a modified version of the VERTEX scheme is developed that simultaneously conserves energy and lepton number in the neutrino transport with better accuracy and higher numerical stability in the high-energy tail of the spectrum. To verify our code, we conduct a series of tests in spherical symmetry, including a detailed comparison with published results of the collapse, shock formation, shock breakout, and accretion phases. Long-time simulations of proto-neutron star cooling until several seconds after core bounce both demonstrate the robustness of the new COCONUT-VERTEX code and show the approximate treatment of relativistic effects by means of an effective relativistic gravitational potential as in
Mueller, Bernhard; Janka, Hans-Thomas; Dimmelmeier, Harald E-mail: thj@mpa-garching.mpg.d
2010-07-15
We present a new general relativistic code for hydrodynamical supernova simulations with neutrino transport in spherical and azimuthal symmetry (one dimension and two dimensions, respectively). The code is a combination of the COCONUT hydro module, which is a Riemann-solver-based, high-resolution shock-capturing method, and the three-flavor, fully energy-dependent VERTEX scheme for the transport of massless neutrinos. VERTEX integrates the coupled neutrino energy and momentum equations with a variable Eddington factor closure computed from a model Boltzmann equation and uses the 'ray-by-ray plus' approximation in two dimensions, assuming the neutrino distribution to be axially symmetric around the radial direction at every point in space, and thus the neutrino flux to be radial. Our spacetime treatment employs the Arnowitt-Deser-Misner 3+1 formalism with the conformal flatness condition for the spatial three metric. This approach is exact for the one-dimensional case and has previously been shown to yield very accurate results for spherical and rotational stellar core collapse. We introduce new formulations of the energy equation to improve total energy conservation in relativistic and Newtonian hydro simulations with grid-based Eulerian finite-volume codes. Moreover, a modified version of the VERTEX scheme is developed that simultaneously conserves energy and lepton number in the neutrino transport with better accuracy and higher numerical stability in the high-energy tail of the spectrum. To verify our code, we conduct a series of tests in spherical symmetry, including a detailed comparison with published results of the collapse, shock formation, shock breakout, and accretion phases. Long-time simulations of proto-neutron star cooling until several seconds after core bounce both demonstrate the robustness of the new COCONUT-VERTEX code and show the approximate treatment of relativistic effects by means of an effective relativistic gravitational potential as in
Neutrino oscillation studies with reactors.
Vogel, P; Wen, L J; Zhang, C
2015-01-01
Nuclear reactors are one of the most intense, pure, controllable, cost-effective and well-understood sources of neutrinos. Reactors have played a major role in the study of neutrino oscillations, a phenomenon that indicates that neutrinos have mass and that neutrino flavours are quantum mechanical mixtures. Over the past several decades, reactors were used in the discovery of neutrinos, were crucial in solving the solar neutrino puzzle, and allowed the determination of the smallest mixing angle θ13. In the near future, reactors will help to determine the neutrino mass hierarchy and to solve the puzzling issue of sterile neutrinos. PMID:25913819
Neutrino oscillation studies with reactors.
Vogel, P; Wen, L J; Zhang, C
2015-04-27
Nuclear reactors are one of the most intense, pure, controllable, cost-effective and well-understood sources of neutrinos. Reactors have played a major role in the study of neutrino oscillations, a phenomenon that indicates that neutrinos have mass and that neutrino flavours are quantum mechanical mixtures. Over the past several decades, reactors were used in the discovery of neutrinos, were crucial in solving the solar neutrino puzzle, and allowed the determination of the smallest mixing angle θ13. In the near future, reactors will help to determine the neutrino mass hierarchy and to solve the puzzling issue of sterile neutrinos.
Neutrino oscillation studies with reactors
Vogel, P.; Wen, L.J.; Zhang, C.
2015-04-27
Nuclear reactors are one of the most intense, pure, controllable, cost-effective and well-understood sources of neutrinos. Reactors have played a major role in the study of neutrino oscillations, a phenomenon that indicates that neutrinos have mass and that neutrino flavours are quantum mechanical mixtures. Over the past several decades, reactors were used in the discovery of neutrinos, were crucial in solving the solar neutrino puzzle, and allowed the determination of the smallest mixing angle θ_{13}. In the near future, reactors will help to determine the neutrino mass hierarchy and to solve the puzzling issue of sterile neutrinos.
Neutrino oscillation studies with reactors
Vogel, P.; Wen, L.J.; Zhang, C.
2015-04-27
Nuclear reactors are one of the most intense, pure, controllable, cost-effective and well-understood sources of neutrinos. Reactors have played a major role in the study of neutrino oscillations, a phenomenon that indicates that neutrinos have mass and that neutrino flavours are quantum mechanical mixtures. Over the past several decades, reactors were used in the discovery of neutrinos, were crucial in solving the solar neutrino puzzle, and allowed the determination of the smallest mixing angle θ13. In the near future, reactors will help to determine the neutrino mass hierarchy and to solve the puzzling issue of sterile neutrinos.
Neutrino oscillation studies with reactors
Vogel, P.; Wen, L.J.; Zhang, C.
2015-01-01
Nuclear reactors are one of the most intense, pure, controllable, cost-effective and well-understood sources of neutrinos. Reactors have played a major role in the study of neutrino oscillations, a phenomenon that indicates that neutrinos have mass and that neutrino flavours are quantum mechanical mixtures. Over the past several decades, reactors were used in the discovery of neutrinos, were crucial in solving the solar neutrino puzzle, and allowed the determination of the smallest mixing angle θ13. In the near future, reactors will help to determine the neutrino mass hierarchy and to solve the puzzling issue of sterile neutrinos. PMID:25913819
Thomson, Mark
2002-05-15
The wave theory of light, and in particular the principle of interference, was formulated by Thomas Young in 1801. In the 20th century, the principle of interference was extended to the quantum mechanical wave functions describing matter. The phenomenon of quantum mechanical interference of different neutrino states, neutrino oscillations, has provided one of the most exciting developments in high energy particle physics of the last decade. Observations of the flavour oscillations of neutrinos produced by distant sources, such as from the core of the Sun, provide compelling evidence that neutrinos have mass. This article describes the main features and the most significant experimental observations of this unusual application of the principle of interference.
symmetry at colliders and in the universe
NASA Astrophysics Data System (ADS)
de Medeiros Varzielas, Ivo; Fischer, Oliver; Maurer, Vinzenz
2015-08-01
Two puzzling facts of our time are the observed patterns in the fermion masses and mixings and the existence of non-baryonic dark matter, which are both often associated with extensions of the Standard Model at higher energy scales. In this paper, we consider a solution to these two problems with the flavour symmetry , in a model which has been shown before to explain large leptonic mixings with a specific texture. The model contains 3 generations of SU(2) L -doublet scalar fields, arranged as an -triplet, that spontaneously break the electroweak symmetry, and a "dark sector" of -odd fields, containing one Majorana neutrino and an -triplet SU(2) L -doublet scalar field, the lightest of which provides a candidate for dark matter.
Soler, F. J. P.
2015-07-15
The Neutrino Factory is a facility that produces neutrino beams with a well-defined flavour content and energy spectrum from the decay of intense, high-energy, stored muon beams to establish CP violation in the neutrino sector. The International Design Study for the Neutrino Factory (the IDS-NF) is providing a Reference Design Report (RDR) for the facility. The present design is optimised for the recent measurements of θ{sub 13}. The accelerator facility will deliver 10{sup 21} muon decays per year from 10 GeV stored muon beams. The straight sections of the storage ring point to a 100 kton Magnetised Iron Neutrino Detector (MIND) at a distance of 2000-2500 km from the source. The accuracy in the value of δ{sub CP} that a Neutrino Factory can achieve and the δ{sub CP} coverage is unrivalled by other future facilities. Staging scenarios for the Neutrino Factory deliver facilities that can carry out physics at each stage. In the context of Fermilab, such a scenario would imply in the first stage the construction of a small storage ring, nuSTORM, to carry out neutrino cross-section and sterile neutrino measurements and to perform a programme of 6D muon cooling R&D. The second stage is the construction of a 5 GeV Neutrino Factory (nuMAX) pointing to the Sanford Underground Research Facility at Homestake and the final stage would use many of the components of this facility to construct a Muon Collider, initially as a 126 GeV CM Higgs Factory, which may be upgraded to a multi-TeV Muon Collider if required.
Rasin, A.
1994-04-01
We discuss the idea of approximate flavor symmetries. Relations between approximate flavor symmetries and natural flavor conservation and democracy models is explored. Implications for neutrino physics are also discussed.
Fermion masses, flavour mixing and CP violation
Ross, G. G.
2008-11-23
The pattern of neutrino masses and mixings is characteristically different from those observed in the quark sector. I discuss how this can be elegantly explaned through a combination of an underlying family symmetry and the see-saw mechanism.
Neutrino oscillations: present status and outlook
Schwetz, Thomas
2008-02-21
I summarize the status of three-flavour neutrino oscillations with date of Oct. 2007, and provide an outlook for the developments to be expected in the near future. Furthermore, I discuss the status of sterile neutrino oscillation interpretations of the LSND anomaly in the light of recent MiniBooNE results, and comment on implications for the future neutrino oscillation program.
Local Hamiltonian Monte Carlo study of the massive schwinger model, the decoupling of heavy flavours
NASA Astrophysics Data System (ADS)
Ranft, J.
1983-12-01
The massive Schwinger model with two flavours is studied using the local hamiltonian lattice Monte Carlo method. Chiral symmetry breaking is studied using the fermion condensate as order parameter. For a small ratio of the two fermion masses, degeneracy of the two flavours is found. For a large ratio of the masses, the heavy flavour decouples and the light fermion behaves like in the one flavour Schwinger model. On leave from Sektion Physik, Karl-Marx-Universität, Leipzig, GDR.
Linear flavour violation and anomalies in B physics
NASA Astrophysics Data System (ADS)
Gripaios, Ben; Nardecchia, Marco; Renner, Sophie
2016-06-01
We propose renormalizable models of new physics that can explain various anomalies observed in decays of B-mesons to electron and muon pairs. The new physics states couple to linear combinations of Standard Model fermions, yielding a pattern of flavour violation that gives a consistent fit to the gamut of flavour data. Accidental symmetries prevent contributions to baryon- and lepton-number-violating processes, as well as enforcing a loop suppression of new physics contributions to flavour violating processes. Data require that the new flavour-breaking couplings are largely aligned with the Yukawa couplings of the SM and so we also explore patterns of flavour symmetry breaking giving rise to this structure.
Flavour-dependent leptogenesis with reheating
Antusch, Stefan
2007-11-20
Upper bounds on the reheat temperature of the early universe, as they appear for example in classes of supergravity models, impose severe constraints on the thermal leptogenesis mechanism. To analyse these constraints, we extend the flavour-dependent treatment of leptogenesis to include reheating. We solve the flavour-dependent Boltzmann equations to obtain the leptogenesis efficiency as a function of the flavour dependent washout parameter m-tilde{sub 1,{alpha}} and of m{sub N{sub 1}}/T{sub RH}, the ratio of the mass of the lightest right-handed neutrino over the reheat temperature, and calculate the minimal values of the reheat temperature compatible with thermal leptogenesis in type I and type II seesaw scenarios.
NASA Astrophysics Data System (ADS)
Cogswell, Bernadette; Latimer, David; Ernst, David
2016-03-01
The role that symmetries play in the phenomenological determination of the six three-neutrino mixing parameters is investigated. From formulae for the oscillation probabilities, we derive the symmetries for two special cases, the CP conserved case (δ = 0 and π) and maximal CP violation case (δ = +/- π / 2). For these two cases, we show that for both cases there are only two independent solutions in vacuum, and due to the interaction with matter, four independent solutions in general. Guided by a broken symmetry, we perform a global analysis for the CP conserved case. We compare in detail our results to three recent global analyses that include CP violation. The comparison is to their results with the CP phase marginalized away. We find that the results for θ13 and Δm232 , which result from the leading order terms of the oscillation formulae, are consistent across the analyses, that negative δ is preferred at a not totally insignificant level, and that there is some indication that the second octant is preferred for θ23.
The inverse seesaw in conformal electro-weak symmetry breaking and phenomenological consequences
NASA Astrophysics Data System (ADS)
Humbert, Pascal; Lindner, Manfred; Smirnov, Juri
2015-06-01
We study the inverse seesaw mechanism for neutrino masses and phenomenological consequences in the context of conformal electro-weak symmetry breaking. The main difference to the usual case is that all explicit fermion mass terms including Majorana masses for neutrinos are forbidden. All fermion mass terms arise therefore from vacuum expectation values of suitable scalars times some Yukawa couplings. This leads to interesting consequences for model building, neutrino mass phenomenology and the Dark Matter abundance. In the context of the inverse seesaw we find a favoured scenario with heavy pseudo-Dirac sterile neutrinos at the TeV scale, which in the conformal framework conspire with the electro-weak scale to generate keV scale warm Dark Matter. The mass scale relations provide naturally the correct relic abundance due to a freeze-in mechanism. We demonstrate also how conformal symmetry decouples the right-handed neutrino mass scale and effective lepton number violation. We find that lepton flavour violating processes can be well within the reach of modern experiments. Furthermore, interesting decay signatures are expected at the LHC.
NASA Astrophysics Data System (ADS)
Queiroz, Farinaldo S.
2016-06-01
Reference [1 S. Mondal and S. K. Rai, Phys. Rev. D 93, 011702 (2016).] recently argued that the projected Large Hadron Electron Collider (LHeC) presents a unique opportunity to discover a left-right symmetry since the LHeC has availability for polarized electrons. In particular, the authors apply some basic pT cuts on the jets and claim that the on-shell production of right-handed neutrinos at the LHeC, which violates lepton number in two units, has practically no standard model background and, therefore, that the right-handed nature of WR interactions that are intrinsic to left-right symmetric models can be confirmed by using colliding beams consisting of an 80% polarized electron and a 7 TeV proton. In this Comment, we show that their findings, as presented, have vastly underestimated the SM background which prevents a Left-Right symmetry signal from being seen at the LHeC.
Another look at synchronized neutrino oscillations
NASA Astrophysics Data System (ADS)
Akhmedov, Evgeny; Mirizzi, Alessandro
2016-07-01
In dense neutrino backgrounds present in supernovae and in the early Universe neutrino oscillations may exhibit complex collective phenomena, such as synchronized oscillations, bipolar oscillations and spectral splits and swaps. We consider in detail possible decoherence effects on the simplest of these phenomena - synchronized neutrino oscillations that can occur in a uniform and isotropic neutrino gas. We develop an exact formalism of spectral moments of the flavour spin vectors describing such a system and then apply it to find analytical approaches that allow one to study decoherence effects on its late-time evolution. This turns out to be possible in part due to the existence of the (previously unknown) exact conservation law satisfied by the quantities describing the considered neutrino system. Interpretation of the decoherence effects in terms of neutrino wave packet separation is also given, both in the adiabatic and non-adiabatic regimes of neutrino flavour evolution.
The problem of the initial conditions in flavoured leptogenesis and the tauon N-dominated scenario
NASA Astrophysics Data System (ADS)
Bertuzzo, Enrico; Di Bari, Pasquale; Marzola, Luca
2011-08-01
We discuss the conditions to realise a scenario of 'strong thermal leptogenesis,' where the final asymmetry is fully independent of the initial conditions, taking into account both heavy and light neutrino flavour effects. In particular, the contribution to the final asymmetry from an initial pre-existing asymmetry has to be negligible. We show that in the case of a hierarchical right-handed (RH) neutrino mass spectrum, the only possible way is an N-dominated leptogenesis scenario with a lightest RH neutrino mass M≪10 GeV and with a next-to-lightest RH neutrino mass 10 GeV≫M≫10 GeV. This scenario necessarily requires the presence of a heaviest third RH neutrino specie. Moreover, we show that the final asymmetry has to be dominantly produced in the tauon flavour while the electron and the muon asymmetries have to be efficiently washed-out by the lightest RH neutrino inverse processes. Intriguingly, such seemingly special conditions for successful strong thermal leptogenesis are naturally fulfilled within SO(10)-inspired models. Besides the tauon N-dominated scenario, successful strong thermal leptogenesis is also achieved in scenarios with quasi-degenerate RH neutrino masses. We also comment on the supersymmetric case. We also derive an expression for the final asymmetry produced from leptogenesis taking fully into account heavy neutrino flavour effects in the specific case M≫10 GeV (heavy flavoured scenario), a result that can be extended to any other mass pattern.
What masses do the neutrinos have? Mixing
Efrosinin, V. P.
2010-06-15
Possible mechanisms for the production of low-mass neutrinos and sterile neutrinos are considered. The quark mixing angles are calculated under the assumption that the traces of left-right symmetry are stable with respect to the masses of constituent quarks. Order-of-magnitude estimates of the neutrino masses are obtained with the aid of experimental data on neutrino oscillations.
Neutrino mass models and CP violation
Joshipura, Anjan S.
2011-10-06
Theoretical ideas on the origin of (a) neutrino masses (b) neutrino mass hierarchies and (c) leptonic mixing angles are reviewed. Topics discussed include (1) symmetries of neutrino mass matrix and their origin (2) ways to understand the observed patterns of leptonic mixing angles and (3)unified description of neutrino masses and mixing angles in grand unified theories.
Measurement of atmospheric neutrino oscillations with the ANTARES neutrino telescope
NASA Astrophysics Data System (ADS)
Adrián-Martínez, S.; Al Samarai, I.; Albert, A.; André, M.; Anghinolfi, M.; Anton, G.; Anvar, S.; Ardid, M.; Astraatmadja, T.; Aubert, J.-J.; Baret, B.; Basa, S.; Bertin, V.; Biagi, S.; Bigongiari, C.; Bogazzi, C.; Bou-Cabo, M.; Bouhou, B.; Bouwhuis, M. C.; Brunner, J.; Busto, J.; Capone, A.; Cârloganu, C.; Carr, J.; Cecchini, S.; Charif, Z.; Charvis, Ph.; Chiarusi, T.; Circella, M.; Coniglione, R.; Core, L.; Costantini, H.; Coyle, P.; Creusot, A.; Curtil, C.; de Bonis, G.; Decowski, M. P.; Dekeyser, I.; Deschamps, A.; Distefano, C.; Donzaud, C.; Dornic, D.; Dorosti, Q.; Drouhin, D.; Eberl, T.; Emanuele, U.; Enzenhöfer, A.; Ernenwein, J.-P.; Escoffier, S.; Fehn, K.; Fermani, P.; Ferri, M.; Ferry, S.; Flaminio, V.; Folger, F.; Fritsch, U.; Fuda, J.-L.; Galatà, S.; Gay, P.; Geyer, K.; Giacomelli, G.; Giordano, V.; Gleixner, A.; Gómez-González, J. P.; Graf, K.; Guillard, G.; Hallewell, G.; Hamal, M.; van Haren, H.; Heijboer, A. J.; Hello, Y.; Hernández-Rey, J. J.; Herold, B.; Hößl, J.; Hsu, C. C.; de Jong, M.; Kadler, M.; Kalekin, O.; Kappes, A.; Katz, U.; Kavatsyuk, O.; Kooijman, P.; Kopper, C.; Kouchner, A.; Kreykenbohm, I.; Kulikovskiy, V.; Lahmann, R.; Lambard, G.; Larosa, G.; Lattuada, D.; Lefèvre, D.; Lim, G.; Lo Presti, D.; Loehner, H.; Loucatos, S.; Louis, F.; Mangano, S.; Marcelin, M.; Margiotta, A.; Martínez-Mora, J. A.; Meli, A.; Montaruli, T.; Morganti, M.; Moscoso, L.; Motz, H.; Neff, M.; Nezri, E.; Palioselitis, D.; Păvălaş, G. E.; Payet, K.; Petrovic, J.; Piattelli, P.; Popa, V.; Pradier, T.; Presani, E.; Racca, C.; Reed, C.; Riccobene, G.; Richardt, C.; Richter, R.; Rivière, C.; Robert, A.; Roensch, K.; Rostovtsev, A.; Ruiz-Rivas, J.; Rujoiu, M.; Russo, G. V.; Samtleben, D. F. E.; Sánchez-Losa, A.; Sapienza, P.; Schmid, J.; Schnabel, J.; Schöck, F.; Schuller, J.-P.; Schüssler, F.; Seitz, T.; Shanidze, R.; Simeone, F.; Spies, A.; Spurio, M.; Steijger, J. J. M.; Stolarczyk, Th.; Taiuti, M.; Tamburini, C.; Trovato, A.; Vallage, B.; Vallée, C.; van Elewyck, V.; Vecchi, M.; Vernin, P.; Visser, E.; Wagner, S.; Wijnker, G.; Wilms, J.; de Wolf, E.; Yepes, H.; Zaborov, D.; Zornoza, J. D.; Zúñiga, J.; ANTARES Collaboration
2012-08-01
The data taken with the ANTARES neutrino telescope from 2007 to 2010, a total live time of 863 days, are used to measure the oscillation parameters of atmospheric neutrinos. Muon tracks are reconstructed with energies as low as 20 GeV. Neutrino oscillations will cause a suppression of vertical upgoing muon neutrinos of such energies crossing the Earth. The parameters determining the oscillation of atmospheric neutrinos are extracted by fitting the event rate as a function of the ratio of the estimated neutrino energy and reconstructed flight path through the Earth. Measurement contours of the oscillation parameters in a two-flavour approximation are derived. Assuming maximal mixing, a mass difference of Δ m322 = (3.1 ± 0.9) ṡ10-3eV2 is obtained, in good agreement with the world average value.
Tau Flavour Violation at the LHC
Carquin, E.
2009-04-17
We study the relevance of neutrino oscillation data for sparticle decays that violate the {tau} lepton number at the LHC, in the context of the Constrained Minimal Supersymmetric Extension of the Standard Model (CMSSM) and in SU(5) extensions of the theory. We study the conditions required for {chi}{sub 2}{yields}{chi}+{tau}{sup {+-}}{mu}{sup {+-}} decays to yield observable tau flavour violation, for cosmologically interesting values of the neutralino relic density. We present detailed studies of the relevant supersymmetric parameter space and pay particular emphasis to signals from tau hadronisation, that are analysed using PYTHIA event simulation.
New Physics Search in Flavour Physics
Hurth, Tobias; /CERN /SLAC
2006-01-04
With the running B, kaon and neutrino physics experiments, flavour physics takes centre stage within today's particle physics. We discuss the opportunities offered by these experiments in our search for new physics beyond the SM and discuss their complementarity to collider physics. We focus on rare B and kaon decays, highlighting specific observables in an exemplary mode. We also comment on the so-called B {yields} {pi}{pi} and B {yields} K{pi} puzzles. Moreover, we briefly discuss the restrictive role of long-distance strong interactions and some new tools such as QCD factorization and SCET to handle them.
A fuller flavour treatment of N-dominated leptogenesis
NASA Astrophysics Data System (ADS)
Antusch, Stefan; Di Bari, Pasquale; Jones, David A.; King, Steve F.
2012-03-01
We discuss N-dominated leptogenesis in the presence of flavour dependent effects that have hitherto been neglected, in particular the off-diagonal entries of the flavour coupling matrix that connects the total flavour asymmetries, distributed in different particle species, to the lepton and Higgs doublet asymmetries. We derive analytical formulae for the final asymmetry including the flavour coupling at the N-decay stage as well as at the stage of wash-out by the lightest right-handed neutrino N. Moreover, we point out that in general part of the electron and muon asymmetries (phantom terms), can completely escape the wash-out at the production and a total B-L asymmetry can be generated by the lightest RH neutrino wash-out yielding so-called phantom leptogenesis. However, the phantom terms are proportional to the initial N abundance and in particular they vanish for initial zero N-abundance. Taking any of these new effects into account can significantly modify the final asymmetry produced by the decays of the next-to-lightest RH neutrinos, opening up new interesting possibilities for N-dominated thermal leptogenesis.
A New Family with a Fourth Lepton Flavour
NASA Astrophysics Data System (ADS)
Sharafiddinov, Rasulkhozha S.
2014-03-01
We present here arguments in favor of the existence of the most lightest lepton and its neutrino. This new family with a fourth lepton flavour in the first turn must uncover so far unobserved universal properties of matter. The unity of their laws predicts the flavour symmetrical schemes for the decays of the electron and the proton. Thereby, it admits the new modes in the decays of the muon, tau lepton and the neutron. At the same time, in all these transitions no conservation laws are violated.
Successful N{sub 2} leptogenesis with flavour coupling effects in realistic unified models
Bari, Pasquale Di; King, Stephen F.
2015-10-02
In realistic unified models involving so-called SO(10)-inspired patterns of Dirac and heavy right-handed (RH) neutrino masses, the lightest right-handed neutrino N{sub 1} is too light to yield successful thermal leptogenesis, barring highly fine tuned solutions, while the second heaviest right-handed neutrino N{sub 2} is typically in the correct mass range. We show that flavour coupling effects in the Boltzmann equations may be crucial to the success of such N{sub 2} dominated leptogenesis, by helping to ensure that the flavour asymmetries produced at the N{sub 2} scale survive N{sub 1} washout. To illustrate these effects we focus on N{sub 2} dominated leptogenesis in an existing model, the A to Z of flavour with Pati-Salam, where the neutrino Dirac mass matrix may be equal to an up-type quark mass matrix and has a particular constrained structure. The numerical results, supported by analytical insight, show that in order to achieve successful N{sub 2} leptogenesis, consistent with neutrino phenomenology, requires a “flavour swap scenario” together with a less hierarchical pattern of RH neutrino masses than naively expected, at the expense of some mild fine-tuning. In the considered A to Z model neutrino masses are predicted to be normal ordered, with an atmospheric neutrino mixing angle well into the second octant and the Dirac phase δ≃20{sup ∘}, a set of predictions that will be tested in the next years in neutrino oscillation experiments. Flavour coupling effects may be relevant for other SO(10)-inspired unified models where N{sub 2} leptogenesis is necessary.
Successful N{sub 2} leptogenesis with flavour coupling effects in realistic unified models
Bari, Pasquale Di; King, Stephen F. E-mail: king@soton.ac.uk
2015-10-01
In realistic unified models involving so-called SO(10)-inspired patterns of Dirac and heavy right-handed (RH) neutrino masses, the lightest right-handed neutrino N{sub 1} is too light to yield successful thermal leptogenesis, barring highly fine tuned solutions, while the second heaviest right-handed neutrino N{sub 2} is typically in the correct mass range. We show that flavour coupling effects in the Boltzmann equations may be crucial to the success of such N{sub 2} dominated leptogenesis, by helping to ensure that the flavour asymmetries produced at the N{sub 2} scale survive N{sub 1} washout. To illustrate these effects we focus on N{sub 2} dominated leptogenesis in an existing model, the A to Z of flavour with Pati-Salam, where the neutrino Dirac mass matrix may be equal to an up-type quark mass matrix and has a particular constrained structure. The numerical results, supported by analytical insight, show that in order to achieve successful N{sub 2} leptogenesis, consistent with neutrino phenomenology, requires a ''flavour swap scenario'' together with a less hierarchical pattern of RH neutrino masses than naively expected, at the expense of some mild fine-tuning. In the considered A to Z model neutrino masses are predicted to be normal ordered, with an atmospheric neutrino mixing angle well into the second octant and the Dirac phase δ≅ 20{sup o}, a set of predictions that will be tested in the next years in neutrino oscillation experiments. Flavour coupling effects may be relevant for other SO(10)-inspired unified models where N{sub 2} leptogenesis is necessary.
Absolute neutrino mass measurements
Wolf, Joachim
2011-10-06
The neutrino mass plays an important role in particle physics, astrophysics and cosmology. In recent years the detection of neutrino flavour oscillations proved that neutrinos carry mass. However, oscillation experiments are only sensitive to the mass-squared difference of the mass eigenvalues. In contrast to cosmological observations and neutrino-less double beta decay (0v2{beta}) searches, single {beta}-decay experiments provide a direct, model-independent way to determine the absolute neutrino mass by measuring the energy spectrum of decay electrons at the endpoint region with high accuracy.Currently the best kinematic upper limits on the neutrino mass of 2.2eV have been set by two experiments in Mainz and Troitsk, using tritium as beta emitter. The next generation tritium {beta}-experiment KATRIN is currently under construction in Karlsruhe/Germany by an international collaboration. KATRIN intends to improve the sensitivity by one order of magnitude to 0.2eV. The investigation of a second isotope ({sup 137}Rh) is being pursued by the international MARE collaboration using micro-calorimeters to measure the beta spectrum. The technology needed to reach 0.2eV sensitivity is still in the R and D phase. This paper reviews the present status of neutrino-mass measurements with cosmological data, 0v2{beta} decay and single {beta}-decay.
NASA Astrophysics Data System (ADS)
Borah, Debasish; Dasgupta, Arnab
2016-07-01
We study the new physics contributions to neutrinoless double beta decay (0 νββ) half-life and lepton flavour violation (LFV) amplitude within the framework of the minimal left-right symmetric model (MLRSM). Considering all possible new physics contributions to 0 νββ and charged lepton flavour violation μ → eγ , μ → 3 e in MLRSM, we constrain the parameter space of the model from the requirement of satisfying existing experimental bounds. Assuming the breaking scale of the left-right symmetry to be O (1) TeV accessible at ongoing and near future collider experiments, we consider the most general type I+II seesaw mechanism for the origin of tiny neutrino masses. Choosing the relative contribution of the type II seesaw term allows us to calculate the right handed neutrino mass matrix as well as Dirac neutrino mass matrix as a function of the model parameters, required for the calculation of 0νββ and LFV amplitudes. We show that such a general type I+II seesaw structure results in more allowed parameter space compared to individual type I or type II seesaw cases considered in earlier works. In particular, we show that the doubly charged scalar masses M Δ are allowed to be smaller than the heaviest right handed neutrino mass M N from the present experimental bounds in these scenarios which is in contrast to earlier results with individual type I or type II seesaw showing M Δ > M N .
Flavour and CPV in SUSYGUTs: Prospects of Observability
Masiero, Antonio; Vempati, Sudhir K.; Vives, O.
2005-12-02
After a quarter of century of intense search for new physics beyond the Standard Model (SM), two ideas stand out to naturally cope with (i) small neutrino masses and (ii) a light higgs boson : Seesaw and SUSY. The combination of these two ideas, i.e. SUSY seesaw exhibits a potentially striking signature: a strong (or even very strong) enhancement of lepton flavour violation (LFV), which on the contrary remains unobservable in the SM seesaw. Indeed, even when supersymmetry breaking is completely flavour blind, Renormalisation Group running effects are expected to generate large lepton flavour violating entries at the weak scale. In Grand Unified theories, these effects can be felt even in hadronic physics. We explicitly show that in a class of SUSY SO(10) GUTs there exist cases where LFV and CP violation in B-physics can constitute a major road in simultaneously confirming the ideas of Seesaw and low-energy SUSY.
SU (3)F gauge family model and new symmetry breaking scale from FCNC processes
NASA Astrophysics Data System (ADS)
Bao, Shou-Shan; Liu, Zhuo; Wu, Yue-Liang
2016-03-01
Based on the SU (3)F gauge family symmetry model which was proposed to explain the observed mass and mixing pattern of neutrinos, we investigate the symmetry breaking, the mixing pattern in quark and lepton sectors, and the contribution of the new gauge bosons to some flavour changing neutral currents (FCNC) processes at low energy. With the current data of the mass differences in the neutral pseudo-scalar P0-Pbar0 systems, we find that the SU (3)F symmetry breaking scale can be as low as 300 TeV and the mass of the lightest gauge boson be about 100 TeV. Other FCNC processes, such as the lepton flavour number violation process μ- →e-e+e- and the semi-leptonic rare decay K → π ν bar ν, contain contributions via the new gauge bosons exchanging. With the constrains obtained from P0-Pbar0 system, we estimate that the contribution of the new physics is around 10-16, far below the current experimental bounds.
Blake, T.
2009-12-17
The large centre of mass energy of the LHC will provide a huge cross-section for heavy flavour production making the LHC a powerful laboratory for studying the indirect effects of new physics. The prospects for four key measurements at LHCb and the central detectors (ATLAS and CMS) are presented.
Understanding flavour at the LHC
None
2016-07-12
Huge progress in flavour physics has been achieved by the two B-factories and the Tevatron experiments. This progress has, however, deepened the new physics flavour puzzle: If there is new physics at the TeV scale, why aren't flavour changing neutral current processes enhanced by orders of magnitude compared to the standard model predictions? The forthcoming ATLAS and CMS experiments can potentially solve this puzzle. Perhaps even more surprisingly, these experiments can potentially lead to progress in understanding the standard model flavour puzzle: Why is there smallness and hierarchy in the flavour parameters? Thus, a rich and informative flavour program is awaiting us not only in the flavour-dedicated LHCb experiment, but also in the high-pT ATLAS and CMS experiments.
Understanding flavour at the LHC
2011-02-08
Huge progress in flavour physics has been achieved by the two B-factories and the Tevatron experiments. This progress has, however, deepened the new physics flavour puzzle: If there is new physics at the TeV scale, why aren't flavour changing neutral current processes enhanced by orders of magnitude compared to the standard model predictions? The forthcoming ATLAS and CMS experiments can potentially solve this puzzle. Perhaps even more surprisingly, these experiments can potentially lead to progress in understanding the standard model flavour puzzle: Why is there smallness and hierarchy in the flavour parameters? Thus, a rich and informative flavour program is awaiting us not only in the flavour-dedicated LHCb experiment, but also in the high-pT ATLAS and CMS experiments.
Atmospheric Neutrinos in the MINOS Far Detector
Howcroft, Caius Leo Frederick
2004-12-01
The phenomenon of flavour oscillations of neutrinos created in the atmosphere was first reported by the Super-Kamiokande collaboration in 1998 and since then has been confirmed by Soudan 2 and MACRO. The MINOS Far Detector is the first magnetized neutrino detector able to study atmospheric neutrino oscillations. Although it was designed to detect neutrinos from the NuMI beam, it provides a unique opportunity to measure the oscillation parameters for neutrinos and anti-neutrinos independently. The MINOS Far Detector was completed in August 2003 and since then has collected 2.52 kton-years of atmospheric data. Atmospheric neutrino interactions contained within the volume of the detector are separated from the dominant background from cosmic ray muons. Thirty seven events are selected with an estimated background contamination of less than 10%. Using the detector's magnetic field, 17 neutrino events and 6 anti-neutrino events are identified, 14 events have ambiguous charge. The neutrino oscillation parameters for v_{μ} and $\\bar{v}$_{μ} are studied using a maximum likelihood analysis. The measurement does not place constraining limits on the neutrino oscillation parameters due to the limited statistics of the data set analysed. However, this thesis represents the first observation of charge separated atmospheric neutrino interactions. It also details the techniques developed to perform atmospheric neutrino analyses in the MINOS Far Detector.
Neutrinos as Probes of Lorentz Invariance
Díaz, Jorge S.
2014-01-01
Neutrinos can be used to search for deviations from exact Lorentz invariance. The worldwide experimental program in neutrino physics makes these particles a remarkable tool to search for a variety of signals that could reveal minute relativity violations. This paper reviews the generic experimental signatures of the breakdown of Lorentz symmetry in the neutrino sector.
Predictive models of radiative neutrino masses
NASA Astrophysics Data System (ADS)
Julio, J.
2016-06-01
We discuss two models of radiative neutrino mass generation. The first model features one-loop Zee model with Z4 symmetry. The second model is the two-loop neutrino mass model with singly- and doubly-charged scalars. These two models fit neutrino oscillation data well and predict some interesting rates for lepton flavor violation processes.
Gauge invariants and correlators in flavoured quiver gauge theories
NASA Astrophysics Data System (ADS)
Mattioli, Paolo; Ramgoolam, Sanjaye
2016-10-01
In this paper we study the construction of holomorphic gauge invariant operators for general quiver gauge theories with flavour symmetries. Using a characterisation of the gauge invariants in terms of equivalence classes generated by permutation actions, along with representation theory results in symmetric groups and unitary groups, we give a diagonal basis for the 2-point functions of holomorphic and anti-holomorphic operators. This involves a generalisation of the previously constructed Quiver Restricted Schur operators to the flavoured case. The 3-point functions are derived and shown to be given in terms of networks of symmetric group branching coefficients. The networks are constructed through cutting and gluing operations on the quivers.
KLOE results in flavour physics and prospects for KLOE-2
NASA Astrophysics Data System (ADS)
Czerwiński, E.; Babusci, D.; Badoni, D.; Balwierz, I.; Bencivenni, G.; Bini, C.; Bloise, C.; Bocci, V.; Bossi, F.; Branchini, P.; Budano, A.; Caldeira Balkeståhl, L.; Capon, G.; Ceradini, F.; Ciambrone, P.; Czerwiński, E.; Dané, E.; De Lucia, E.; De Robertis, G.; De Santis, A.; Di Domenico, A.; Di Donato, C.; Di Salvo, R.; Domenici, D.; Erriquez, O.; Fanizzi, G.; Fantini, A.; Felici, G.; Fiore, S.; Franzini, P.; Gauzzi, P.; Giardina, G.; Giovannella, S.; Gonnella, F.; Graziani, E.; Happacher, F.; Höistad, B.; Iafolla, L.; Iarocci, E.; Jacewicz, M.; Johansson, T.; Kupść, A.; Lee-Franzini, J.; Leverington, B.; Loddo, F.; Mandaglio, G.; Martemianov, M.; Martini, M.; Mascolo, M.; Messi, R.; Miscetti, S.; Morello, G.; Moricciani, D.; Moskal, P.; Nguyen, F.; Passeri, A.; Patera, V.; Prado Longhi, I.; Ranieri, A.; Redmer, C. F.; Santangelo, P.; Sarra, I.; Schioppa, M.; Sciascia, B.; Silarski, M.; Taccini, C.; Tortora, L.; Venanzoni, G.; Versaci, R.; Wiślicki, W.; Wolke, M.; Zdebik, J.
2013-08-01
A review of the most recent results in flavour physics obtained by the KLOE experiment at DAΦNE collider together with prospects for kaon physics at KLOE-2 is presented. A brief description of KS meson lifetime measurement and determination of upper limit for BR(Ks→3π0) are discussed. In addition a CPT symmetry test in the Standard Model Extension framework and study of the Dalitz plot of η→π+π-π0 are reported. Last two sections are devoted to the KLOE-2 project and prospects in flavour physics.
Future flavour physics experiments
2015-01-01
The current status of flavour physics and the prospects for present and future experiments will be reviewed. Measurements in B‐physics, in which sensitive probes of new physics are the CKM angle γ, the Bs mixing phase ϕs, and the branching ratios of the rare decays B(s)0→μ+μ− , will be highlighted. Topics in charm and kaon physics, in which the measurements of ACP and the branching ratios of the rare decays K→πνν¯ are key measurements, will be discussed. Finally the complementarity of the future heavy flavour experiments, the LHCb upgrade and Belle‐II, will be summarised. PMID:26877543
Twisted flavors and tribimaximal neutrino mixing.
Haba, Naoyuki; Watanabe, Atsushi; Yoshioka, Koichi
2006-07-28
A new framework for handling flavor symmetry breaking in the neutrino sector is discussed where the source of symmetry breaking is traced to the global property of right-handed neutrinos in extra-dimensional space. Light neutrino phenomenology has rich and robust predictions such as the tribimaximal form of generation mixing, controlled mass spectrum, and no need of flavor mixing couplings in the theory.
McKeown, R. D.
2010-08-04
Recent studies of neutrino oscillations have established the existence of finite neutrino masses and mixing between generations of neutrinos. The combined results from studies of atmospheric neutrinos, solar neutrinos, reactor antineutrinos and neutrinos produced at accelerators paint an intriguing picture that clearly requires modification of the standard model of particle physics. These results also provide clear motivation for future neutrino oscillation experiments as well as searches for direct neutrino mass and nuclear double-beta decay. I will discuss the program of new neutrino oscillation experiments aimed at completing our knowledge of the neutrino mixing matrix.
Solar Neutrinos, SNO and SNOLAB
NASA Astrophysics Data System (ADS)
McDonald, A. B.
2007-06-01
The Sudbury Neutrino Observatory has completed operation in its third phase with an array of neutron detectors in 1000 tonnes of heavy water and Cherenkov light detection 2 km underground in INCO's Creighton mine near Sudbury, Ontario, Canada. Data from the third phase is now being analyzed. In the first two phases of the project reported previously, the neutral current reaction on deuterium was used to determine the total flux of active neutrinos and the charged current reaction on deuterium provided a measure of the flux and energy spectrum of solar electron neutrinos. The flux of electron neutrinos was found to be only about one third of the total flux, providing clear evidence of neutrino flavour change. The total flux of active neutrinos was found to be in agreement with solar model calculations. The underground laboratory is being expanded to create an international facility known as SNOLAB that will be completed at the end of 2007. Proposed future experiments for the detection of lower energy solar neutrinos, geo-neutrinos, dark matter and double beta decay are described.
Quantum correlations in terms of neutrino oscillation probabilities
NASA Astrophysics Data System (ADS)
Alok, Ashutosh Kumar; Banerjee, Subhashish; Uma Sankar, S.
2016-08-01
Neutrino oscillations provide evidence for the mode entanglement of neutrino mass eigenstates in a given flavour eigenstate. Given this mode entanglement, it is pertinent to consider the relation between the oscillation probabilities and other quantum correlations. In this work, we show that all the well-known quantum correlations, such as the Bell's inequality, are directly related to the neutrino oscillation probabilities. The results of the neutrino oscillation experiments, which measure the neutrino survival probability to be less than unity, imply Bell's inequality violation.
Flavour-changing Higgs couplings in a class of two Higgs doublet models
NASA Astrophysics Data System (ADS)
Botella, F. J.; Branco, G. C.; Nebot, M.; Rebelo, M. N.
2016-03-01
We analyse various flavour-changing processes like trightarrow hu,hc, hrightarrow τ e,τ μ as well as hadronic decays hrightarrow bs,bd, in the framework of a class of two Higgs doublet models where there are flavour-changing neutral scalar currents at tree level. These models have the remarkable feature of having these flavour-violating couplings entirely determined by the CKM and PMNS matrices as well as tan β . The flavour structure of these scalar currents results from a symmetry of the Lagrangian and therefore it is natural and stable under the renormalisation group. We show that in some of the models the rates of the above flavour-changing processes can reach the discovery level at the LHC at 13 TeV even taking into account the stringent bounds on low energy processes, in particular μ rightarrow eγ.
Probing neutrino nature at Borexino detector with chromium neutrino source
NASA Astrophysics Data System (ADS)
Sobków, W.; Błaut, A.
2016-10-01
In this paper, we indicate a possibility of utilizing the intense chromium source (˜ 370 PBq) in probing the neutrino nature in low energy neutrino experiments with the ultra-low threshold and background real-time Borexino detector located near the source (˜ 8 m). We analyse the elastic scattering of electron neutrinos (Dirac or Majorana, respectively) on the unpolarised electrons in the relativistic neutrino limit. We assume that the incoming neutrino beam is the superposition of left-right chiral states produced by the chromium source. Left chiral neutrinos may be detected by the standard V - A and non-standard scalar S_L, pseudoscalar P_L, tensor T_L interactions, while right chiral ones partake only in the exotic V + A and S_R, P_R, T_R interactions. Our model-independent study is carried out for the flavour (current) neutrino eigenstates. We compute the expected event number for the standard V-A interaction of the left chiral neutrinos using the current experimental values of standard couplings and in the case of left-right chiral superposition. We show that the significant decrement in the event number due to the interference terms between the standard and exotic interactions for the Majorana neutrinos may appear. We also demonstrate how the presence of the exotic couplings affects the energy spectrum of outgoing electrons, both for the Dirac and Majorana cases. The 90~% C.L. sensitivity contours in the planes of corresponding exotic couplings are found. The presence of interferences in the Majorana case gives the stronger constraints than for the Dirac neutrinos, even if the neutrino source is placed outside the detector.
Quigg, Chris; /Fermilab /CERN
2008-02-01
I recall the place of neutrinos in the electroweak theory and summarize what we know about neutrino mass and flavor change. I next review the essential characteristics expected for relic neutrinos and survey what we can say about the neutrino contribution to the dark matter of the Universe. Then I discuss the standard-model interactions of ultrahigh-energy neutrinos, paying attention to the consequences of neutrino oscillations, and illustrate a few topics of interest to neutrino observatories. I conclude with short comments on the remote possibility of detecting relic neutrinos through annihilations of ultrahigh-energy neutrinos at the Z resonance.
Anarchic Yukawas and top partial compositeness: the flavour of a successful marriage
NASA Astrophysics Data System (ADS)
Cacciapaglia, Giacomo; Cai, Haiying; Flacke, Thomas; Lee, Seung J.; Parolini, Alberto; Serôdio, Hugo
2015-06-01
The top quark can be naturally singled out from other fermions in the Standard Model due to its large mass, of the order of the electroweak scale. We follow this reasoning in models of pseudo Nambu Goldstone Boson composite Higgs, which may derive from an underlying confining dynamics. We consider a new class of flavour models, where the top quark obtains its mass via partial compositeness, while the lighter fermions acquire their masses by a deformation of the dynamics generated at a high flavour scale. One interesting feature of such scenario is that it can avoid all the flavour constraints without the need of flavour symmetries, since the flavour scale can be pushed high enough. We show that both flavour conserving and violating constraints can be satisfied with top partial compositeness without invoking any flavour symmetry for the up-type sector, in the case of the minimal SO(5)/SO(4) coset with top partners in the four-plet and singlet of SO(4). In the down-type sector, some degree of alignment is required if all down-type quarks are elementary. We show that taking the bottom quark partially composite provides a dynamical explanation for the hierarchy causing this alignment. We present explicit realisations of this mechanism which do not require to include additional bottom partner fields. Finally, these conclusions are generalised to scenarios with non-minimal cosets and top partners in larger representations.
Yeomans, Martin R; Mobini, Sirous; Chambers, Lucy
2007-12-01
Previous research has established that caffeine consumption can reinforce changes in liking for caffeine-paired flavours, while pairing a novel flavour with a liked or dislike taste can also result in enduring changes in liking for the flavour. The present study examined how these two forms of flavour-learning interact. 72 habitual caffeine consumers who liked sweet tastes rated the odour and flavour of a novel tea drink before and after four training sessions where the flavour was paired with either 100 mg caffeine or placebo in one of three flavour contexts: added sweetness (aspartame), bitterness (quinine) or control. The liking for both the odour and flavour of the tea increased after pairing with caffeine regardless of flavour context, while pairing with bitterness reduced flavour liking regardless of the presence of caffeine. Pairing with quinine increased the rated bitterness of the tea odour, and reduced the rated sweetness of the tea flavour, post-training, independent of effects of caffeine. These data suggest that flavour-caffeine and flavour-flavour associations have additive effects on drink liking, while confirming that flavour-flavour associations can alter the immediate sensory experience of a flavour alone.
Impact of leptogenesis and muon g-2 on lepton flavour violation in supersymmetric seesaw models
Endo, Motoi; Shindou, Tetsuo
2009-04-17
The framework of supersymmetric see-saw models are considered. The successful leptogenesis scenarios which are due to a decay of the right-handed neutrinos tends to require rather heavy right-handed neutrinos. On the other hand, a discrepancy of the anomalous magnetic moment of the muon reported between the experimental and theoretical results implies lighter supersymmetric particles. In the light of successful leptogenesis scenarios, this anomaly of the anomalous magnetic moment of the muon leads to sizable lepton-flavour violations. It is shown that for a hierarchical right-handed neutrino mass spectrum, {mu}{yields}e{gamma} is expected to be observed in near future experiments.
Flavor instabilities in the neutrino line model
NASA Astrophysics Data System (ADS)
Duan, Huaiyu; Shalgar, Shashank
2015-07-01
A dense neutrino medium can experience collective flavor oscillations through nonlinear neutrino-neutrino refraction. To make this multi-dimensional flavor transport problem more tractable, all existing studies have assumed certain symmetries (e.g., the spatial homogeneity and directional isotropy in the early universe) to reduce the dimensionality of the problem. In this work we show that, if both the directional and spatial symmetries are not enforced in the neutrino line model, collective oscillations can develop in the physical regimes where the symmetry-preserving oscillation modes are stable. Our results suggest that collective neutrino oscillations in real astrophysical environments (such as core-collapse supernovae and black-hole accretion discs) can be qualitatively different from the predictions based on existing models in which spatial and directional symmetries are artificially imposed.
Possible scenario for MaVaN's as the only neutrino flavor conversion mechanism in the Sun
Holanda, P.C. de
2009-07-01
Mass Varying neutrino mechanisms were proposed to link the neutrino mass scale with dark energy, addressing the coincidence problem. In some scenarios this mass can present a dependence on the baryonic density felt by neutrinos, creating an effective neutrino mass that depends both on the neutrino and baryonic densities. In this article we investigate the possibility that a neutrino effective mass in matter in addition to a very small mass squared difference in vacuum (O(10{sup −9} eV{sup 2})) are the main flavour conversion mechanism acting in neutrino oscillation experiments. We present a parameterization on the environmental effects on neutrino mass that produces the right flavour conversion probabilities for solar and terrestrial neutrinos experiments.
Right-handed neutrinos at CERN LHC and the mechanism of neutrino mass generation
Kersten, Joern; Smirnov, Alexei Yu.
2007-10-01
We consider the possibility to detect right-handed neutrinos, which are mostly singlets of the standard model gauge group, at future accelerators. Substantial mixing of these neutrinos with the active neutrinos requires a cancellation of different contributions to the light neutrino mass matrix at the level of 10{sup -8}. We discuss possible symmetries behind this cancellation and argue that for three right-handed neutrinos they always lead to conservation of total lepton number. Light neutrino masses can be generated by small perturbations violating these symmetries. In the most general case, LHC physics and the mechanism of neutrino mass generation are essentially decoupled; with additional assumptions, correlations can appear between collider observables and features of the neutrino mass matrix.
Gravity triggered neutrino condensates
Barenboim, Gabriela
2010-11-01
In this work we use the Schwinger-Dyson equations to study the possibility that an enhanced gravitational attraction triggers the formation of a right-handed neutrino condensate, inducing dynamical symmetry breaking and generating a Majorana mass for the right-handed neutrino at a scale appropriate for the seesaw mechanism. The composite field formed by the condensate phase could drive an early epoch of inflation. We find that to the lowest order, the theory does not allow dynamical symmetry breaking. Nevertheless, thanks to the large number of matter fields in the model, the suppression by additional powers in G of higher order terms can be compensated, boosting them up to their lowest order counterparts. This way chiral symmetry can be broken dynamically and the infrared mass generated turns out to be in the expected range for a successful seesaw scenario.
Lepton flavour violating slepton decays to test type-I and II seesaw at the LHC
Villanova del Moral, Albert
2010-02-10
Searches at the LHC of lepton flavour violation (LFV) in slepton decays can indirectly test both type-I and II seesaw mechanisms. Assuming universal flavour-blind boundary conditions, LFV in the neutrino sector is related to LFV in the slepton sector by means of the renormalization group equations. Ratios of LFV slepton decay rates result to be a very effective way to extract the imprint left by the neutrino sector. Some neutrino scenarios within the type-I seesaw mechanism are studied. Moreover, for both type-I and II seesaw mechanisms, a scan over the minimal super-gravity parameter space is performed to estimate how large LFV slepton decay rates can be, while respecting current low-energy constraints.
B decays and lepton flavour (universality) violation
NASA Astrophysics Data System (ADS)
Crivellin, A.
2016-07-01
LHCb found hints for physics beyond the standard model in Bto K^*μ^+μ^- , Bto K^*μ^+μ^-/Bto K^*e^+e^- and B_stoφμ^+μ^- . In addition, the BABAR results for Bto D^{(*)}τν and the CMS excess in htoτ^±μ^∓ also point towards lepton flavour (universality) violating new physics. While Bto D^{(*)}τν and htoτ^±μ^∓ can be naturally explained by an extended Higgs sector, the probably most promising explanation for the bto sμμ anomalies is a Z' boson. Furthermore, combining a 2HDM with a gauged L_μ-L_τ symmetry allows for explaining the bto sμ^+μ^- anomalies and htoτ^±μ^∓ simultaneously, with interesting correlations to τto3μ . In the light of these deviations from the SM we also discuss the possibilities of observing lepton flavour violating B decays ( e.g. Bto K^{(*)}τ^±μ^∓ and B_stoτ^±μ^∓ in Z^' models.
First real-time detection of solar pp neutrinos by Borexino
NASA Astrophysics Data System (ADS)
Pallavicini, M.; Bellini, G.; Benziger, J.; Bick, D.; Bonfini, G.; Bravo, D.; Caccianiga, B.; Calaprice, F.; Caminata, A.; Cavalcante, P.; Chavarria, A.; Chepurnov, A.; D'Angelo, D.; Davini, S.; Derbin, A.; Empl, A.; Etenko, A.; Fomenko, K.; Franco, D.; Gabriele, F.; Galbiati, C.; Gazzana, S.; Ghiano, C.; Giammarchi, M.; Göger-Neff, M.; Goretti, A.; Gromov, M.; Hagner, C.; Hungerford, E.; Ianni, Al.; Ianni, An.; Kayser, M.; Kobychev, V.; Korablëv, D.; Korga, G.; Kryn, D.; Laubenstein, M.; Lehnert, B.; Lewke, T.; Litvinovich, E.; Lombardi, F.; Lombardi, P.; Ludhova, L.; Lukyanchenko, G.; Machulin, I.; Manecki, S.; Maneschg, W.; Marcocci, S.; Meindl, Q.; Meroni, E.; Meyer, M.; Miramonti, L.; Misiaszek, M.; Montuschi, M.; Mosteiro, P.; Muratova, V.; Oberauer, L.; Obolensky, M.; Ortica, F.; Otis, K.; Papp, L.; Perasso, L.; Pocar, A.; Ranucci, G.; Razeto, A.; Re, A.; Romani, A.; Rossi, N.; Saldanha, R.; Salvo, C.; Schönert, S.; Simgen, H.; Skorokhvatov, M.; Smirnov, O.; Sotnikov, A.; Sukhotin, S.; Suvorov, Y.; Tartaglia, R.; Testera, G.; Vignaud, D.; Vogelaar, R. B.; von Feilitzsch, F.; Wang, H.; Winter, J.; Wojcik, M.; Wurm, M.; Zaimidoroga, O.; Zavatarelli, S.; Zuber, K.; Zuzel, G.
2016-07-01
Solar neutrinos have been pivotal to the discovery of neutrino flavour oscillations and are a unique tool to probe the reactions that keep the Sun shine. Although most of solar neutrino components have been directly measured, the neutrinos emitted by the keystone pp reaction, in which two protons fuse to make a deuteron, have so far eluded direct detection. The Borexino experiment, an ultra-pure liquid scintillator detector running at the Laboratori Nazionali del Gran Sasso in Italy, has now filled the gap, providing the first direct real time measurement of pp neutrinos and of the solar neutrino luminosity.
Hernandez-Galeana, Albino
2007-11-01
I report the analysis performed on fermion masses and mixing, including neutrino mixing, within the context of a model with hierarchical radiative mass generation mechanism for light charged fermions, mediated by exotic scalar particles at one and two loops, respectively, meanwhile the neutrinos get Majorana mass terms at tree level through the Yukawa couplings with two SU(2){sub L} Higgs triplets. All the resulting mass matrices in the model, for the u, d, and e fermion charged sectors, the neutrinos and the exotic scalar particles, are diagonalized in exact analytical form. Quantitative analysis shows that this model is successful to accommodate the hierarchical spectrum of masses and mixing in the quark sector as well as the charged lepton masses. The lepton mixing matrix, V{sub PMNS}, is written completely in terms of the neutrino masses m{sub 1}, m{sub 2}, and m{sub 3}. Large lepton mixing for {theta}{sub 12} and {theta}{sub 23} is predicted in the range of values 0.7 < or approx. sin{sup 2}2{theta}{sub 12} < or approx. 0.7772 and 0.87 < or approx. sin{sup 2}2{theta}{sub 23} < or approx. 0.9023 by using 0.033 < or approx. s{sub 13}{sup 2} < or approx. 0.04. These values for lepton mixing are consistent with 3{sigma} allowed ranges provided by recent global analysis of neutrino data oscillation. From {delta}m{sub sol}{sup 2} bounds, neutrino masses are predicted in the range of values m{sub 1}{approx_equal}(1.706-2.494)x10{sup -3} eV, m{sub 2}{approx_equal}(6.675-12.56)x10{sup -3} eV, and m{sub 3}{approx_equal}(1.215-2.188)x10{sup -2} eV, respectively. The above allowed lepton mixing leads to the quark-lepton complementary relations {theta}{sub 12}{sup CKM}+{theta}{sub 12}{sup PMNS}{approx_equal}41.543 deg. -44.066 deg. and {theta}{sub 23}{sup CKM}+{theta}{sub 23}{sup PMNS}{approx_equal}36.835 deg. -38.295 deg. The new exotic scalar particles induce flavor changing neutral currents and contribute to lepton flavor violating processes such as E{yields}e{sub 1}e
NASA Astrophysics Data System (ADS)
Mondal, Subhadeep; Rai, Santosh Kumar
2016-06-01
The Comment against our work [S. Mondal and S. K. Rai, Phys. Rev. D 93, 011702 (2016)., 10.1103/PhysRevD.93.011702] is based on a presumptive and incorrectly chosen large value of "charge-flip" probability. We address the concerns of the author and show why the values chosen and the estimates of the background cross section given in the Comment become irrelevant when folded in with expected numbers for the efficiency provided by an analysis done by the CMS Collaboration for a heavy Majorana neutrino search after proper event selection criteria are set for the final states.
Approximate flavor symmetries in the lepton sector
Rasin, A. ); Silva, J.P. )
1994-01-01
Approximate flavor symmetries in the quark sector have been used as a handle on physics beyond the standard model. Because of the great interest in neutrino masses and mixings and the wealth of existing and proposed neutrino experiments it is important to extend this analysis to the leptonic sector. We show that in the seesaw mechanism the neutrino masses and mixing angles do not depend on the details of the right-handed neutrino flavor symmetry breaking, and are related by a simple formula. We propose several [ital Ansa]$[ital uml]---[ital tze] which relate different flavor symmetry-breaking parameters and find that the MSW solution to the solar neutrino problem is always easily fit. Further, the [nu][sub [mu]-][nu][sub [tau
DOE R&D Accomplishments Database
Lederman, L. M.
1963-01-09
The prediction and verification of the neutrino are reviewed, together with the V A theory for its interactions (particularly the difficulties with the apparent existence of two neutrinos and the high energy cross section). The Brookhaven experiment confirming the existence of two neutrinos and the cross section increase with momentum is then described, and future neutrino experiments are considered. (D.C.W.)
PREFACE: DISCRETE '08: Symposium on Prospects in the Physics of Discrete Symmetries
NASA Astrophysics Data System (ADS)
Bernabéu, José; Botella, Francisco J.; Mavromatos, Nick E.; Mitsou, Vasiliki A.
2009-07-01
and Francis Halzen gave the present status of High Energy Neutrino Astronomy and the projects towards Km3-scale cosmic neutrino Underwater Detectors. On Neutrino Physics, Niki Saoulidou reviewed its present status and the experimental prospects, Peter Minkowski discussed the proposals to understand the Origin of Neutrino Mass and Apostolos Pilaftsis made a Little Review on the implications of global Lepton Number Violation with neutrino Majorana mass for Leptogenesis in the Universe. The interplay of Dark Matter studies with the search for SUSY at LHC was discussed by Antonio Masiero, whereas Athanasios Lahanas presented Dark Matter in the eye of CP-violating SUSY theory. On the Experimental Prospects frontier, André Rubbia discussed Underground Detectors for Particle and Astroparticle Science, Daniel Froidevaux gave a stimulating review on the Physics to be expected at LHC, Marcello A Giorgi examined the Future of SuperFlavour Factories as complementary to LHCb and Mats Lindroos presented the options for the Ultimate Neutrino Beam(s), able to discover and measure CP Violation in neutrino oscillations. In the Parallel Sessions, the contributions selected for oral presentation during the Symposium were well balanced covering all aspects of Discrete Symmetries. They are reproduced in the present Proceedings distributed according to the various topic-specific sessions in which they were presented. The papers published here have, in addition, passed positively the refereeing system defined by the members of the Organising Committee of the DISCRETE'08 Symposium. The DISCRETE'08 Symposium was the first in a series of biannual events on the general topic of Symmetries. The next symposium will be organised by the University of La Sapienza, Rome, Italy, in the autumn of 2010. Valencia, April 2009 The Editors J Bernabéu (IFIC Valencia) F J Botella (IFIC Valencia) N E Mavromatos (King's College London) V A Mitsou (IFIC Valencia)
Harris, Deborah A.; /Fermilab
2008-09-01
The field of neutrino physics has expanded greatly in recent years with the discovery that neutrinos change flavor and therefore have mass. Although there are many neutrino physics results since the last DIS workshop, these proceedings concentrate on recent neutrino physics results that either add to or depend on the understanding of Deep Inelastic Scattering. They also describe the short and longer term future of neutrino DIS experiments.
Collective neutrino flavor conversion: Recent developments
NASA Astrophysics Data System (ADS)
Chakraborty, Sovan; Hansen, Rasmus; Izaguirre, Ignacio; Raffelt, Georg
2016-07-01
Neutrino flavor evolution in core-collapse supernovae, neutron-star mergers, or the early universe is dominated by neutrino-neutrino refraction, often spawning "self-induced flavor conversion," i.e., shuffling of flavor among momentum modes. This effect is driven by collective run-away modes of the coupled "flavor oscillators" and can spontaneously break the initial symmetries such as axial symmetry, homogeneity, isotropy, and even stationarity. Moreover, the growth rates of unstable modes can be of the order of the neutrino-neutrino interaction energy instead of the much smaller vacuum oscillation frequency: self-induced flavor conversion does not always require neutrino masses. We illustrate these newly found phenomena in terms of simple toy models. What happens in realistic astrophysical settings is up to speculation at present.
Probing the origins of neutrino mass with supernova data.
Davoudiasl, Hooman; Huber, Patrick
2005-11-01
We study type II supernova signatures of neutrino mass generation via symmetry breaking at a scale in the range from keV to MeV. The scalar responsible for symmetry breaking is thermalized in the supernova core and restores the symmetry. The neutrinos from scalar decays have about half the average energy of thermal neutrinos. The Bose-Einstein distribution of the scalars can be established with a megaton water Cerenkov detector. The discovery of the bimodal neutrino flux is, however, well within the reach of the Super-Kamiokande detector, without a detailed knowledge of the supernova parameters.
Goldstone bosons as fractional cosmic neutrinos.
Weinberg, Steven
2013-06-14
It is suggested that Goldstone bosons may be masquerading as fractional cosmic neutrinos, contributing about 0.39 to what is reported as the effective number of neutrino types in the era before recombination. The broken symmetry associated with these Goldstone bosons is further speculated to be the conservation of the particles of dark matter. PMID:25165907
NASA Astrophysics Data System (ADS)
He, Xiao-Gang
2016-07-01
Since the discovery of neutrino oscillations, for which Takaaki Kajita and Arthur B. McDonald were awarded the 2015 Nobel prize in physics, tremendous progresses have been made in measuring the mixing angles which determine the oscillation pattern. A lot of theoretical efforts have been made to understand how neutrinos mix with each other. Present data show that in the standard parameterization of the mixing matrix, θ23 is close to π/4 and the CP violating phase is close to - π/2. In this talk I report results obtained in arXiv:1505.01932 (Phys. Lett. B750(2015)620) and arXive:1404.01560 (Chin. J. Phys.53(2015)100101) and discuss some implications for theoretical model buildings for such mixing pattern. Specific examples for neutrino mixing based on A4 family symmetry are given.
NASA Astrophysics Data System (ADS)
He, Xiao-Gang
2016-07-01
Since the discovery of neutrino oscillations, for which Takaaki Kajita and Arthur B. McDonald were awarded the 2015 Nobel prize in physics, tremendous progresses have been made in measuring the mixing angles which determine the oscillation pattern. A lot of theoretical efforts have been made to understand how neutrinos mix with each other. Present data show that in the standard parameterization of the mixing matrix, θ23 is close to π/4 and the CP violating phase is close to ‑ π/2. In this talk I report results obtained in arXiv:1505.01932 (Phys. Lett. B750(2015)620) and arXive:1404.01560 (Chin. J. Phys.53(2015)100101) and discuss some implications for theoretical model buildings for such mixing pattern. Specific examples for neutrino mixing based on A4 family symmetry are given.
Flavourful production at hadron colliders
NASA Astrophysics Data System (ADS)
Giudice, Gian Francesco; Gripaios, Ben; Sundrum, Raman
2011-08-01
We ask what new states may lie at or below the TeV scale, with sizable flavour-dependent couplings to light quarks, putting them within reach of hadron colliders via resonant production, or in association with Standard Model states. In particular, we focus on the compatibility of such states with stringent flavour-changing neutral current and electric-dipole moment constraints. We argue that the broadest and most theoretically plausible flavour structure of the new couplings is that they are hierarchical, as are Standard Model Yukawa couplings, although the hierarchical pattern may well be different. We point out that, without the need for any more elaborate or restrictive structure, new scalars with "diquark" couplings to standard quarks are particularly immune to existing constraints, and that such scalars may arise within a variety of theoretical paradigms. In particular, there can be substantial couplings to a pair of light quarks or to one light and one heavy quark. For example, the latter possibility may provide a flavour-safe interpretation of the asymmetry in top quark production observed at the Tevatron. We thereby motivate searches for diquark scalars at the Tevatron and LHC, and argue that their discovery represents one of our best chances for new insight into the Flavour Puzzle of the Standard Model.
Vives, O.
2006-04-01
We prove that taking correctly into account the lepton flavour dependence of the CP asymmetries and washout processes, it is possible to obtain successful thermal leptogenesis from the decays of the second right-handed neutrino. The asymmetries in the muon and tau-flavour channels are then not erased by the inverse decays of the lightest right-handed neutrino N{sub 1}. In this way, we reopen the possibility of ''thermal leptogenesis'' in models with a strong hierarchy in the right-handed Majorana masses that is typically the case in models with up-quark neutrino-Yukawa unification.
Higgs and flavour as doors to new physics
NASA Astrophysics Data System (ADS)
Sala, Filippo
2016-04-01
A natural solution to the hierarchy problem of the Fermi scale motivates signals of New Physics at current and near-future experiments. After a critical synthesis of this general motivation, we concentrate our attention on the interplay between LHC searches for new resonances, and precision measurements of both Higgs couplings and flavour violating observables. We do so for i) the Higgs sectors of the NMSSM and MSSM, as paradigmatic examples of theories providing extra scalars, and for ii) CKM-like flavour symmetries, with a focus on U(2)3. This article is mainly based on several papers by the author, but it also reviews other recent related results. Its goal is to provide a synthetic, yet comprehensive, orientation on these subjects, at the dawn of several (ATLAS and CMS, LHCb, NA62, etc.) forthcoming experimental results.
A tight SO(10) connection between leptogenesis and neutrino masses
Frigerio, Michele
2008-11-23
We discuss a source of light neutrino masses and leptogenesis in SO(10) unification theories, that was not previously recognized. It is present when the light lepton doublets belong (at least partially) to dimension-10 matter multiplets. At odds with previous leptogenesis scenarios, the CP asymmetry depends only on the low energy flavour parameters of the neutrino sector. We demonstrate that a successful generation of the baryon asymmetry of the Universe is possible.
Heavy Flavour production at RHIC
Kabana, Sonia
2010-12-22
We present a review of Heavy Flavour production in p+p, d+Au and A+A collisions at the Relativistic Heavy Ion Collider (RHIC). We focus on two important topics, jet quenching and quarkonia. Anomalous energy loss (jet quenching) of quarks passing through the dense and hot matter build in heavy ion collisions is one of the outstanding discoveries made at RHIC, allowing for an estimate of the initial density. Furthermore, color screening of hidden charm and beauty states is a key signature of the QCD phase transition, allowing an estimate of the initial temperature. We present results on the flavour dependence of jet quenching. Heavy flavour production in A+A as compared to p+p collisions will be discussed for open and hidden charm.
Bounds on Neutrino Non-Standard Interactions
Fernandez-Martinez, Enrique
2010-03-30
We review the present model independent bounds on neutrino non-standard interactions both at neutrino production and detection and in its interactions with matter. For matter non-standard interactions the direct bounds are rather weak. However, matter non-standard interactions are related by gauge invariance to the production and detection ones as well as to flavour changing processes involving charged leptons. Taking into account these relations much stronger bounds of at least O(10{sup -2}) can be derived unless significant fine tunings are implemented. Testing non-standard interactions at this level at future neutrino oscillation facilities is challenging but still feasible at very ambitious proposals such as the Neutrino Factory.
Geer, Steve; /Fermilab
2010-01-01
Over the last decade there has been significant progress in developing the concepts and technologies needed to produce, capture and accelerate O(10{sup 21}) muons/year. This prepares the way for a Neutrino Factory (NF) in which high energy muons decay within the straight sections of a storage ring to produce a beam of neutrinos and anti-neutrinos. The NF concept was proposed in 1997 at a time when the discovery that the three known types of neutrino ({nu}{sub e}, {nu}{sub {mu}}, {nu}{sub {tau}}) can change their flavor as they propagate through space (neutrino oscillations) was providing a first glimpse of physics beyond the Standard Model. This development prepares the way for a new type of neutrino source: a Neutrino Factory. This article reviews the motivation, design and R&D for a Neutrino Factory.
Overview and Status of Experimental Neutrino Physics
NASA Astrophysics Data System (ADS)
Stancu, Ion
2002-10-01
Seventy years after the existence of the neutrino has been postulated by Wolfgang Pauli, these elusive particles remain surrounded by mystery. One of the most fundamental questions about neutrinos is whether they have an identically vanishing mass, as assumed by the Standard Model, or not. Direct measurements have proven to be extremely difficult to perform, and have yielded so far only upper limits. However, if neutrino flavour oscillations do happen, this would automatically imply that at least one of the three neutrinos (the electron, muon or tau neutrino) must have a non-zero mass. The present experimental data indicate that both the solar and atmospheric neutrino deficits can be explained by the phenomenon of neutrino oscillations, while the positive signal reported by the accelerator-based LSND experiment remains to be verified by an independent measurement (MiniBooNE). This talk reviews the current status of the neutrino oscillations experiments, experiments which are quite likely to produce results with significant consequences for both the Standard Model and Cosmology.
Neutrino astronomy and gamma-ray bursts.
Waxman, Eli
2007-05-15
The construction of large-volume detectors of high energy, greater than 1TeV, neutrinos is mainly driven by the search for extragalactic neutrino sources. The existence of such sources is implied by the observations of ultra-high-energy, greater than or equal to 1019eV, cosmic rays, the origin of which is a mystery. In this lecture, I briefly discuss the expected extragalactic neutrino signal and the current state of the experimental efforts. Neutrino emission from gamma-ray bursts (GRBs), which are probably sources of both high-energy protons and neutrinos, is discussed in some detail. The detection of the predicted GRB neutrino signal, which may become possible in the coming few years, will allow one to identify the sources of ultra-high-energy cosmic rays and to resolve open questions related to the underlying physics of GRB models. Moreover, detection of GRB neutrinos will allow one to test for neutrino properties (e.g. flavour oscillations and coupling to gravity) with an accuracy many orders of magnitude better than is currently possible.
Kayser, Boris; /Fermilab
2005-06-01
Thanks to compelling evidence that neutrinos can change flavor, we now know that they have nonzero masses, and that leptons mix. In these lectures, we explain the physics of neutrino flavor change, both in vacuum and in matter. Then, we describe what the flavor-change data have taught us about neutrinos. Finally, we consider some of the questions raised by the discovery of neutrino mass, explaining why these questions are so interesting, and how they might be answered experimentally.
NASA Astrophysics Data System (ADS)
Geer, Steve
2010-06-01
Over the last decade there has been significant progress in developing the concepts and technologies needed to produce, capture and accelerate O(1021) muons/year. This development prepares the way for a new type of neutrino source : a Neutrino Factory. This article reviews the motivation, design and R&D for a Neutrino Factory.
NASA Astrophysics Data System (ADS)
von Feilitzsch, Franz; Lanfranchi, Jean-Côme; Wurm, Michael
The neutrino was postulated by Wolfgang Pauli in the early 1930s, but could only be detected for the first time in the 1950s. Ever since scientists all around the world have worked on the detection and understanding of this particle which so scarcely interacts with matter. Depending on the origin and nature of the neutrino, various types of experiments have been developed and operated. In this entry, we will review neutrino detectors in terms of neutrino energy and associated detection technique as well as the scientific outcome of some selected examples. After a brief historical introduction, the detection of low-energy neutrinos originating from nuclear reactors or from the Earth is used to illustrate the principles and difficulties which are encountered in detecting neutrinos. In the context of solar neutrino spectroscopy, where the neutrino is used as a probe for astrophysics, three different types of neutrino detectors are presented - water Čerenkov, radiochemical, and liquid-scintillator detectors. Moving to higher neutrino energies, we discuss neutrinos produced by astrophysical sources and from accelerators. The entry concludes with an overview of a selection of future neutrino experiments and their scientific goals.
Leptogenesis in the E{sub 6}SSM: Flavour Dependent Lepton Asymmetries
King, S. F.; Luo, R.; Miller, D. J.; Nevzorov, R.
2008-11-23
We discuss flavour dependent lepton asymmetries in the Exceptional Supersymmetric Standard Model (E{sub 6}SSM). In the E{sub 6}SSM, the right-handed neutrinos do not participate in gauge interactions, and they decay into leptons and leptoquarks. Their Majorana nature allows violation of lepton number. New particles and interactions can result in substantial lepton asymmetries, even for scales as low as 10{sup 6} GeV.
Restrictions on the lifetime of sterile neutrinos from primordial nucleosynthesis
Ruchayskiy, Oleg; Ivashko, Artem E-mail: ivashko@lorentz.leidenuniv.nl
2012-10-01
We analyze the influence of sterile neutrinos with the masses in the MeV range on the primordial abundances of Helium-4 and Deuterium. We solve explicitly the Boltzmann equations for all particle species, taking into account neutrino flavour oscillations and demonstrate that the abundances are sensitive mostly to the sterile neutrino lifetime and only weakly to the way the active-sterile mixing is distributed between flavours. The decay of these particles also perturbs the spectra of (decoupled) neutrinos and heats photons, changing the ratio of neutrino to photon energy density, that can be interpreted as extra neutrino species at the recombination epoch. We derive upper bounds on the lifetime of sterile neutrinos based on both astrophysical and cosmological measurements of Helium-4 and Deuterium. We also demonstrate that the recent results of Izotov and Thuan [1], who find 2σ higher than predicted by the standard primordial nucleosynthesis value of Helium-4 abundance, are consistent with the presence in the plasma of sterile neutrinos with the lifetime 0.01–2 seconds.
Leptogenesis from a Flavour Perspective
Losada, Marta
2007-06-19
Leptogenesis is a successful mechanism interlacing particle physics and cosmology to describe the observed matter-antimatter asymmetry of the Universe. We briefly review the standard scenario and describe the novel features that appear when a more accurate analysis including flavour is performed.
NASA Astrophysics Data System (ADS)
Palazzo, Antonio
2016-05-01
Several anomalies recorded in short-baseline neutrino experiments suggest the possibility that the standard 3-flavor framework may be incomplete and point towards a manifestation of new physics. Light sterile neutrinos provide a credible solution to these puzzling results. Here, we present a concise review of the status of the neutrino oscillations within the 3+1 scheme, the minimal extension of the standard 3-flavor framework endowed with one sterile neutrino species. We emphasize the potential role of LBL experiments in the searches of CP violation related to sterile neutrinos and their complementarity with the SBL experiments.
Charged lepton corrections to scaling neutrino mixing
NASA Astrophysics Data System (ADS)
Dev, S.; Gautam, Radha Raman; Singh, Lal
2014-01-01
Assuming the Majorana nature of neutrinos, a general expression for the charged lepton corrections to scaling neutrino mixing has been obtained in the context of three flavor neutrino oscillations. The nonzero value of the reactor mixing angle is nicely accommodated. It is noted that scaling in the effective neutrino mass matrix is equivalent to the presence of two vanishing minors corresponding to first row elements of the effective neutrino mass matrix. A value of the reactor mixing angle which is fairly close to the currently measured best fit is predicted for charged lepton corrections of the order of the Cabbibo angle. We also present symmetry realization of such texture structures in the framework of the type-I seesaw mechanism with a nondiagonal charged lepton mass matrix using discrete Abelian flavor symmetry.
The kinetics of thermal generation of flavour.
Parker, Jane K
2013-01-01
Control and optimisation of flavour is the ultimate challenge for the food and flavour industry. The major route to flavour formation during thermal processing is the Maillard reaction, which is a complex cascade of interdependent reactions initiated by the reaction between a reducing sugar and an amino compound. The complexity of the reaction means that researchers turn to kinetic modelling in order to understand the control points of the reaction and to manipulate the flavour profile. Studies of the kinetics of flavour formation have developed over the past 30 years from single- response empirical models of binary aqueous systems to sophisticated multi-response models in food matrices, based on the underlying chemistry, with the power to predict the formation of some key aroma compounds. This paper discusses in detail the development of kinetic models of thermal generation of flavour and looks at the challenges involved in predicting flavour. PMID:23184881
Model of neutrino effective masses
Dinh Nguyen Dinh; Nguyen Thi Hong Van; Nguyen Anh Ky; Phi Quang Van
2006-10-01
It is shown that an effective (nonrenormalizable) coupling of lepton multiplets to scalar triplets in the 331 model with sterile/exotic neutrinos, can be a good way for generating neutrino masses of different types. The method is simple and avoids radiative/loop calculations which, sometimes, are long and complicated. Basing on some astrophysical arguments it is also stated that the scale of SU(3){sub L} symmetry breaking is at TeV scale, in agreement with earlier investigations. Or equivalently, starting from this symmetry breaking scale we could have sterile/exotic neutrinos with mass of a few keV's which could be used to explain several astrophysical and cosmological puzzles, such as the dark matter, the fast motion of the observed pulsars, the re-ionization of the Universe, etc.
Neutrino-Argon Interaction with GENIE Event Generator
NASA Astrophysics Data System (ADS)
Chesneanu, Daniela
2010-11-01
Neutrinos are very special particles, have only weak interactions, except gravity, and are produced in very different processes in Nuclear and Particle Physics. Neutrinos are, also, messengers from astrophysical objects, as well as relics from Early Universe. Therefore, its can give us information on processes happening in the Universe, during its evolution, which cannot be studied otherwise. The underground instrumentation including a variety of large and very large detectors, thanks to technical breakthroughs, have achieved new fundamental results like the solution of the solar neutrino puzzle and the evidence for Physics beyond the Standard Model of elementary interactions in the neutrino sector with non-vanishing neutrino masses and lepton flavour violation. Two of the LAGUNA (Large Apparatus studying Grand Unification and Neutrino Astrophysics) detectors, namely: GLACIER (Giant Liquid Argon Charge Imaging ExpeRiment) [1] and LENA (Low Energy Neutrino Astrophysics) [2] could be emplaced in ``Unirea'' salt mine from Slănic-Prahova, Romania. A detailed analysis of the conditions and advantages is necessary. A few results have been presented previously [3]. In the present work, we propose to generate events and compute the cross sections for interactions between neutrino and Argon-40, to estimate possible detection performances and event types. For doing this, we use the code GENIE (G_enerates E_vents for N_eutrino I_nteraction E_xperiments) [4]. GENIE Code is an Object-Oriented Neutrino MC Generator supported and developed by an international collaboration of neutrino interaction experts.
Probing Neutrino Properties with Long-Baseline Neutrino Beams
Marino, Alysia
2015-06-29
This is nal report on an Early Career Award grant began in April 15, 2010 and concluded on April 14, 2015. Alysia Marino's research is fo- cussed on making precise measurements of neutrino properties using in- tense accelerator-generated neutrino beams. As a part of this grant, she is collaborating on the Tokai-to-Kamioka (T2K) long-baseline neutrino exper- iment [6], currently taking data in Japan, and on the Deep Underground Neutrino Experiment (DUNE) design e ort for a future Long-Baseline Neu- trino Facility (LBNF) in the US.1 She is also a member of the NA61/SHINE particle production experiment at CERN, but as that e ort is supported by other funds, it will not be discussed further here. T2K was designed to search for the disappearance of muon neutrinos ( ) and the appearance of electron neutrinos ( e), using a beam of muon neu- trino beam that travels 295 km across Japan towards the Super-Kamiokande detector. In 2011 T2K rst reported indications of e appearance [2], a pre- viously unobserved mode of neutrino oscillations. In the past year, T2K has published a combined analysis of disappearance and e appearance [1], and began collecting taking data with a beam of anti-neutrinos, instead of neutrinos, to search for hints of violation of the CP symmetry of the uni- verse. The proposed DUNE experiment has similar physics goals to T2K, but will be much more sensitive due to its more massive detectors and new higher-intensity neutrino beam. This e ort will be very high-priority particle physics project in the US over the next decade.
Bogomilov, M.; Matev, R.; Tsenov, R.; Dracos, M.; Bonesini, M.; Palladino, V.; Tortora, L.; Mori, Y.; Planche, T.; Lagrange, J. B.; et al
2014-12-08
The properties of the neutrino provide a unique window on physics beyond that described by the standard model. The study of subleading effects in neutrino oscillations, and the race to discover CP-invariance violation in the lepton sector, has begun with the recent discovery that theta(13) > 0. The measured value of theta(13) is large, emphasizing the need for a facility at which the systematic uncertainties can be reduced to the percent level. The neutrino factory, in which intense neutrino beams are produced from the decay of muons, has been shown to outperform all realistic alternatives and to be capable ofmore » making measurements of the requisite precision. Its unique discovery potential arises from the fact that only at the neutrino factory is it practical to produce high-energy electron (anti) neutrino beams of the required intensity. This paper presents the conceptual design of the neutrino factory accelerator facility developed by the European Commission Framework Programme 7 EURO nu. Design Study consortium. EURO nu coordinated the European contributions to the International Design Study for the Neutrino Factory (the IDS-NF) collaboration. The EURO nu baseline accelerator facility will provide 10(21) muon decays per year from 12.6 GeV stored muon beams serving a single neutrino detector situated at a source-detector distance of between 1 500 km and 2 500 km. A suite of near detectors will allow definitive neutrino-scattering experiments to be performed.« less
Bogomilov, M.; Matev, R.; Tsenov, R.; Dracos, M.; Bonesini, M.; Palladino, V.; Tortora, L.; Mori, Y.; Planche, T.; Lagrange, J. B.; Kuno, Y.; Benedetto, E.; Efthymiopoulos, I.; Garoby, R.; Gilardoini, S.; Martini, M.; Wildner, E.; Prior, G.; Blondel, A.; Karadzhow, Y.; Ellis, M.; Kyberd, P.; Bayes, R.; Laing, A.; Soler, F. J. P.; Alekou, A.; Apollonio, M.; Aslaninejad, M.; Bontoiu, C.; Jenner, L. J.; Kurup, A.; Long, K.; Pasternak, J.; Zarrebini, A.; Poslimski, J.; Blackmore, V.; Cobb, J.; Tunnell, C.; Andreopoulos, C.; Bennett, J. R.J.; Brooks, S.; Caretta, O.; Davenne, T.; Densham, C.; Edgecock, T. R.; Fitton, M.; Kelliher, D.; Loveridge, P.; McFarland, A.; Machida, S.; Prior, C.; Rees, G.; Rogers, C.; Rooney, M.; Thomason, J.; Wilcox, D.; Booth, C.; Skoro, G.; Back, J. J.; Harrison, P.; Berg, J. S.; Fernow, R.; Gallardo, J. C.; Gupta, R.; Kirk, H.; Simos, N.; Stratakis, D.; Souchlas, N.; Witte, H.; Bross, A.; Geer, S.; Johnstone, C.; Makhov, N.; Neuffer, D.; Popovic, M.; Strait, J.; Striganov, S.; Morfín, J. G.; Wands, R.; Snopok, P.; Bagacz, S. A.; Morozov, V.; Roblin, Y.; Cline, D.; Ding, X.; Bromberg, C.; Hart, T.; Abrams, R. J.; Ankenbrandt, C. M.; Beard, K. B.; Cummings, M. A.C.; Flanagan, G.; Johnson, R. P.; Roberts, T. J.; Yoshikawa, C. Y.; Graves, V. B.; McDonald, K. T.; Coney, L.; Hanson, G.
2014-12-08
The properties of the neutrino provide a unique window on physics beyond that described by the standard model. The study of subleading effects in neutrino oscillations, and the race to discover CP-invariance violation in the lepton sector, has begun with the recent discovery that theta(13) > 0. The measured value of theta(13) is large, emphasizing the need for a facility at which the systematic uncertainties can be reduced to the percent level. The neutrino factory, in which intense neutrino beams are produced from the decay of muons, has been shown to outperform all realistic alternatives and to be capable of making measurements of the requisite precision. Its unique discovery potential arises from the fact that only at the neutrino factory is it practical to produce high-energy electron (anti) neutrino beams of the required intensity. This paper presents the conceptual design of the neutrino factory accelerator facility developed by the European Commission Framework Programme 7 EURO nu. Design Study consortium. EURO nu coordinated the European contributions to the International Design Study for the Neutrino Factory (the IDS-NF) collaboration. The EURO nu baseline accelerator facility will provide 10(21) muon decays per year from 12.6 GeV stored muon beams serving a single neutrino detector situated at a source-detector distance of between 1 500 km and 2 500 km. A suite of near detectors will allow definitive neutrino-scattering experiments to be performed.
NASA Astrophysics Data System (ADS)
Bogomilov, M.; Matev, R.; Tsenov, R.; Dracos, M.; Bonesini, M.; Palladino, V.; Tortora, L.; Mori, Y.; Planche, T.; Lagrange, J. B.; Kuno, Y.; Benedetto, E.; Efthymiopoulos, I.; Garoby, R.; Gilardoini, S.; Martini, M.; Wildner, E.; Prior, G.; Blondel, A.; Karadzhow, Y.; Ellis, M.; Kyberd, P.; Bayes, R.; Laing, A.; Soler, F. J. P.; Alekou, A.; Apollonio, M.; Aslaninejad, M.; Bontoiu, C.; Jenner, L. J.; Kurup, A.; Long, K.; Pasternak, J.; Zarrebini, A.; Poslimski, J.; Blackmore, V.; Cobb, J.; Tunnell, C.; Andreopoulos, C.; Bennett, J. R. J.; Brooks, S.; Caretta, O.; Davenne, T.; Densham, C.; Edgecock, T. R.; Fitton, M.; Kelliher, D.; Loveridge, P.; McFarland, A.; Machida, S.; Prior, C.; Rees, G.; Rogers, C.; Rooney, M.; Thomason, J.; Wilcox, D.; Booth, C.; Skoro, G.; Back, J. J.; Harrison, P.; Berg, J. S.; Fernow, R.; Gallardo, J. C.; Gupta, R.; Kirk, H.; Simos, N.; Stratakis, D.; Souchlas, N.; Witte, H.; Bross, A.; Geer, S.; Johnstone, C.; Makhov, N.; Neuffer, D.; Popovic, M.; Strait, J.; Striganov, S.; Morfín, J. G.; Wands, R.; Snopok, P.; Bagacz, S. A.; Morozov, V.; Roblin, Y.; Cline, D.; Ding, X.; Bromberg, C.; Hart, T.; Abrams, R. J.; Ankenbrandt, C. M.; Beard, K. B.; Cummings, M. A. C.; Flanagan, G.; Johnson, R. P.; Roberts, T. J.; Yoshikawa, C. Y.; Graves, V. B.; McDonald, K. T.; Coney, L.; Hanson, G.
2014-12-01
The properties of the neutrino provide a unique window on physics beyond that described by the standard model. The study of subleading effects in neutrino oscillations, and the race to discover CP-invariance violation in the lepton sector, has begun with the recent discovery that θ13>0 . The measured value of θ13 is large, emphasizing the need for a facility at which the systematic uncertainties can be reduced to the percent level. The neutrino factory, in which intense neutrino beams are produced from the decay of muons, has been shown to outperform all realistic alternatives and to be capable of making measurements of the requisite precision. Its unique discovery potential arises from the fact that only at the neutrino factory is it practical to produce high-energy electron (anti)neutrino beams of the required intensity. This paper presents the conceptual design of the neutrino factory accelerator facility developed by the European Commission Framework Programme 7 EURO ν Design Study consortium. EURO ν coordinated the European contributions to the International Design Study for the Neutrino Factory (the IDS-NF) collaboration. The EURO ν baseline accelerator facility will provide 1 021 muon decays per year from 12.6 GeV stored muon beams serving a single neutrino detector situated at a source-detector distance of between 1 500 km and 2 500 km. A suite of near detectors will allow definitive neutrino-scattering experiments to be performed.
Testing Pomeron flavour symmetry with diffractive W charge asymmetry
NASA Astrophysics Data System (ADS)
Chuinard, A.; Royon, C.; Staszewski, R.
2016-04-01
This study focuses on hard diffractive events produced in proton-proton collision at LHC exhibiting one intact proton in the final state which can be tagged by forward detectors. We report prospective results on the W boson charge asymmetry measured for such events, which allow to constrain the quark diffractive density functions in the Pomeron.
Dirac neutrino mass from a neutrino dark matter model for the galaxy cluster Abell 1689
NASA Astrophysics Data System (ADS)
Nieuwenhuizen, Theodorus Maria
2016-03-01
The dark matter in the galaxy cluster Abell 1689 is modelled as an isothermal sphere of neutrinos. New data on the 2d mass density allow an accurate description of its core and halo. The model has no “missing baryon problem” and beyond 2.1 Mpc the baryons have the cosmic mass abundance. Combination of cluster data with the cosmic dark matter fraction - here supposed to stem from the neutrinos - leads to a solution of the dark matter riddle by left and right handed neutrinos with mass (1.861 ± 0.016)h 70 -2eV/c 2. The thus far observed absence of neutrinoless double beta decay points to (quasi-) Dirac neutrinos: uncharged electrons with different flavour and mass eigenbasis, as for quarks. Though the cosmic microwave background spectrum is matched up to some 10% accuracy only, the case is not ruled out because the plasma phase of the early Universe may be turbulent.
Neutrino Oscillations With Two Sterile Neutrinos
NASA Astrophysics Data System (ADS)
Kisslinger, Leonard S.
2016-10-01
This work estimates the probability of μ to e neutrino oscillation with two sterile neutrinos using a 5×5 U-matrix, an extension of the previous estimate with one sterile neutrino and a 4×4 U-matrix. The sterile neutrino-active neutrino mass differences and the mixing angles of the two sterile neutrinos with the three active neutrinos are taken from recent publications, and the oscillation probability for one sterile neutrino is compared to the previous estimate.
Neutrino Oscillations With Two Sterile Neutrinos
NASA Astrophysics Data System (ADS)
Kisslinger, Leonard S.
2016-06-01
This work estimates the probability of μ to e neutrino oscillation with two sterile neutrinos using a 5×5 U-matrix, an extension of the previous estimate with one sterile neutrino and a 4×4 U-matrix. The sterile neutrino-active neutrino mass differences and the mixing angles of the two sterile neutrinos with the three active neutrinos are taken from recent publications, and the oscillation probability for one sterile neutrino is compared to the previous estimate.
The remarkable history of the discovery of neutrino oscillations
NASA Astrophysics Data System (ADS)
Perkins, Don H.
2014-12-01
The experimental observation of neutrino flavour oscillations took place some 30 years after they had been first proposed, and even then came about principally as a result of an anomalously low value in the measurement of the electroweak mixing angle, resulting in the possible validity of the minimal SU(5) grand unification scheme and the prediction of proton decay. In turn this led to underground experiments which failed in their original objective, but were to discover - purely as a background - the oscillatory behaviour of neutrino flavour, due to a fortuitous fourfold coincidence in the values of the neutrino mass differences, the Earth's radius and magnetic field and the tiny value of the Fermi constant.
DOE R&D Accomplishments Database
Davis, R. Jr.; Harmer, D. S.
1964-12-01
The prospect of studying the solar energy generation process directly by observing the solar neutrino radiation has been discussed for many years. The main difficulty with this approach is that the sun emits predominantly low energy neutrinos, and detectors for observing low fluxes of low energy neutrinos have not been developed. However, experimental techniques have been developed for observing neutrinos, and one can foresee that in the near future these techniques will be improved sufficiently in sensitivity to observe solar neutrinos. At the present several experiments are being designed and hopefully will be operating in the next year or so. We will discuss an experiment based upon a neutrino capture reaction that is the inverse of the electron-capture radioactive decay of argon-37. The method depends upon exposing a large volume of a chlorine compound, removing the radioactive argon-37 and observing the characteristic decay in a small low-level counter.
New neutrino mass sum rule from the inverse seesaw mechanism
NASA Astrophysics Data System (ADS)
Dorame, L.; Morisi, S.; Peinado, E.; Valle, J. W. F.; Rojas, Alma D.
2012-09-01
A class of discrete flavor-symmetry-based models predicts constrained neutrino mass matrix schemes that lead to specific neutrino mass sum rules. One of these implies a lower bound on the effective neutrinoless double beta mass parameter, even for normal hierarchy neutrinos. Here we propose a new model based on the S4 flavor symmetry that leads to the new neutrino mass sum rule and discuss how to generate a nonzero value for the reactor angle θ13 indicated by recent experiments, and the resulting correlation with the solar angle θ12.
Bowles, T.J.
1994-04-01
The existence of a finite neutrino mass would have important consequences in particle physics, astrophysics, and cosmology. Experimental sensitivities have continued to be pushed down without any confirmed evidence for a finite neutrino mass. Yet there are several observations of discrepancies between theoretical predictions and observations which might be possible indications of a finite neutrino mass. Thus, extensive theoretical and experimental work is underway to resolve these issues.
Linking natural supersymmetry to flavour physics
NASA Astrophysics Data System (ADS)
Dudas, Emilian; von Gersdorff, Gero; Pokorski, Stefan; Ziegler, Robert
2014-01-01
With the aim of linking natural supersymmetry to flavour physics, a model is proposed based on a family symmetry G × U(1), where G is a discrete nonabelian subgroup of SU(2), with both F-term and (abelian) D-term supersymmetry breaking. A good fit to the fermion masses and mixing is obtained with the same U(1) charges for the left- and right- handed quarks of the first two families and the right-handed bottom quark, and with zero charge for the left-handed top-bottom doublet and the the right handed top. The model shows an interesting indirect correlation between the correct prediction for the V ub /V cb ratio and large right-handed rotations in the ( s, b) sector, required to diagonalise the Yukawa matrix. For the squarks, one obtains almost degenerate first two generations. The main source of the FCNC and CP violation effects is the splitting between the first two families and the right-handed sbottom determined by the relative size of F-term and D-term supersymmetry breaking. The presence of the large right-handed rotation implies that the bounds on the masses of the first two families of squarks and the right handed sbottom are in a few to a few tens TeV range. The picture that emerges is light stops and left handed sbottom and much heavier other squarks.
Atmospheric neutrinos and discovery of neutrino oscillations.
Kajita, Takaaki
2010-01-01
Neutrino oscillation was discovered through studies of neutrinos produced by cosmic-ray interactions in the atmosphere. These neutrinos are called atmospheric neutrinos. They are produced as decay products in hadronic showers resulting from collisions of cosmic rays with nuclei in the atmosphere. Electron-neutrinos and muon-neutrinos are produced mainly by the decay chain of charged pions to muons to electrons. Atmospheric neutrino experiments observed zenith-angle and energy dependent deficit of muon-neutrino events. Neutrino oscillations between muon-neutrinos and tau-neutrinos explain these data well. Neutrino oscillations imply that neutrinos have small but non-zero masses. The small neutrino masses have profound implications to our understanding of elementary particle physics and the Universe. This article discusses the experimental discovery of neutrino oscillations.
Atmospheric neutrinos and discovery of neutrino oscillations
Kajita, Takaaki
2010-01-01
Neutrino oscillation was discovered through studies of neutrinos produced by cosmic-ray interactions in the atmosphere. These neutrinos are called atmospheric neutrinos. They are produced as decay products in hadronic showers resulting from collisions of cosmic rays with nuclei in the atmosphere. Electron-neutrinos and muon-neutrinos are produced mainly by the decay chain of charged pions to muons to electrons. Atmospheric neutrino experiments observed zenith-angle and energy dependent deficit of muon-neutrino events. Neutrino oscillations between muon-neutrinos and tau-neutrinos explain these data well. Neutrino oscillations imply that neutrinos have small but non-zero masses. The small neutrino masses have profound implications to our understanding of elementary particle physics and the Universe. This article discusses the experimental discovery of neutrino oscillations. PMID:20431258
Global constraints on heavy neutrino mixing
NASA Astrophysics Data System (ADS)
Fernandez-Martinez, Enrique; Hernandez-Garcia, Josu; Lopez-Pavon, Jacobo
2016-08-01
We derive general constraints on the mixing of heavy Seesaw neutrinos with the SM fields from a global fit to present flavour and electroweak precision data. We explore and compare both a completely general scenario, where the heavy neutrinos are integrated out without any further assumption, and the more constrained case were only 3 additional heavy states are considered. The latter assumption implies non-trivial correlations in order to reproduce the correct neutrino masses and mixings as observed by oscillation data and thus some qualitative differences can be found with the more general scenario. The relevant processes analyzed in the global fit include searches for Lepton Flavour Violating (LFV) decays, probes of the universality of weak interactions, CKM unitarity bounds and electroweak precision data. In particular, a comparative and detailed study of the present and future sensitivity of the different LFV experiments is performed. We find a mild 1-2σ preference for non-zero heavy neutrino mixing of order 0.03-0.04 in the electron and tau sectors. At the 2σ level we derive bounds on all mixings ranging from 0.1 to 0.01 with the notable exception of the e - μ sector with a more stringent bound of 0.005 from the μ → eγ process.
Neutrino-Argon Interaction with GENIE Event Generator
Chesneanu, Daniela
2010-11-24
Neutrinos are very special particles, have only weak interactions, except gravity, and are produced in very different processes in Nuclear and Particle Physics. Neutrinos are, also, messengers from astrophysical objects, as well as relics from Early Universe. Therefore, its can give us information on processes happening in the Universe, during its evolution, which cannot be studied otherwise. The underground instrumentation including a variety of large and very large detectors, thanks to technical breakthroughs, have achieved new fundamental results like the solution of the solar neutrino puzzle and the evidence for Physics beyond the Standard Model of elementary interactions in the neutrino sector with non-vanishing neutrino masses and lepton flavour violation.Two of the LAGUNA(Large Apparatus studying Grand Unification and Neutrino Astrophysics) detectors, namely: GLACIER (Giant Liquid Argon Charge Imaging ExpeRiment) and LENA (Low Energy Neutrino Astrophysics) could be emplaced in 'Unirea' salt mine from Slanic-Prahova, Romania. A detailed analysis of the conditions and advantages is necessary. A few results have been presented previously. In the present work, we propose to generate events and compute the cross sections for interactions between neutrino and Argon-40, to estimate possible detection performances and event types. For doing this, we use the code GENIE(G lowbar enerates E lowbar vents for N lowbar eutrino I lowbar nteraction E lowbar xperiments). GENIE Code is an Object-Oriented Neutrino MC Generator supported and developed by an international collaboration of neutrino interaction experts.
Flavour chemicals in electronic cigarette fluids
Tierney, Peyton A; Karpinski, Clarissa D; Brown, Jessica E; Luo, Wentai; Pankow, James F
2016-01-01
Background Most e-cigarette liquids contain flavour chemicals. Flavour chemicals certified as safe for ingestion by the Flavor Extracts Manufacturers Association may not be safe for use in e-cigarettes. This study identified and measured flavour chemicals in 30 e-cigarette fluids. Methods Two brands of single-use e-cigarettes were selected and their fluids in multiple flavour types analysed by gas chromatography/mass spectrometry. For the same flavour types, and for selected confectionary flavours (eg, bubble gum and cotton candy), also analysed were convenience samples of e-cigarette fluids in refill bottles from local ‘vape’ shops and online retailers. Results In many liquids, total flavour chemicals were found to be in the ∼1–4% range (10–40 mg/mL); labelled levels of nicotine were in the range of 0.6–2.4% (6 to 24 mg/mL). A significant number of the flavour chemicals were aldehydes, a compound class recognised as ‘primary irritants’ of mucosal tissue of the respiratory tract. Many of the products contained the same flavour chemicals: vanillin and/or ethyl vanillin was found in 17 of the liquids as one of the top three flavour chemicals, and/or at ≥0.5 mg/mL. Conclusions The concentrations of some flavour chemicals in e-cigarette fluids are sufficiently high for inhalation exposure by vaping to be of toxicological concern. Regulatory limits should be contemplated for levels of some of the more worrisome chemicals as well as for total flavour chemical levels. Ingredient labeling should also be required. PMID:25877377
Why Are Neutrinos Light? -- An Alternative
Hall, Lawrence J.; Oliver, Steven J.
2004-09-23
We review the recent proposal that neutrinos are light because their masses are proportional to a low scale, f, of lepton flavor symmetry breaking. This mechanism is testable because the resulting pseudo-Goldstone bosons, of mass m_G, couple strongly with the neutrinos, affecting the acoustic oscillations during the eV era of the early universe that generate the peaks in the CMB radiation. Characteristic signals result over a very wide range of (f, m_G) because of a change in the total relativistic energy density and because the neutrinos scatter rather than free-stream. Thermodynamics allows a precise calculation of the signal, so that observations would not only confirm the late-time neutrino mass mechanism, but could also determine whether the neutrino spectrum is degenerate, inverted or hierarchical and whether the neutrinos are Dirac or Majorana. The flavor symmetries could also give light sterile states. If the masses of the sterile neutrinos turn on after the MeV era, the LSND oscillations can be explained without upsetting big bang nucleosynthesis, and, since the sterile states decay to lighter neutrinos and pseudo-Goldstones, without giving too much hot dark matter.
Study of Neutrino Interactions in MINOS
Sharma, Richa
2014-01-01
MINOS stands for Main Injector Neutrino Oscillation Search. It is a long baseline experiment located in the USA and is composed of two detectors. The Near Detector is at Fermilab, 1 km from the source of neutrinos. The Far Detector is in Minnesota at a distance of 735 km from the source. Both detectors are steel scintillator tracking calorimeters. MINOS searches for neutrino oscillations by comparing the neutrino energy spectrum at the Far Detector with that obtained from a prediction based on the spectrum at the Near Detector. The primary aim of MINOS is to measure the atmospheric oscillation parameters Δm^{2} _{32} and θ_{23}. CPT symmetry requires that these parameters should be same for neutrinos and antineutrinos. Di erences between neutrino and antineutrino oscillations would be an indication of new physics beyond the neutrino-Standard Model ( SM). Additionally, violation of Lorentz or CPT symmetry could also give rise to oscillations di erent from that expected from the SM predictions, such as neutrino to antineutrino transitions.
Possible Neutrino-Antineutrino Oscillation Under Gravity and its Consequences
NASA Astrophysics Data System (ADS)
Mukhopadhyay, Banibrata
2008-09-01
We show that under gravity the effective masses for neutrino and antineutrino are different which opens a possible window of neutrino-antineutrino oscillation even if the rest masses of the corresponding eigenstates are same. This is due to CPT violation and possible to demonstrate if the neutrino mass eigenstates are expressed as a combination of neutrino and antineutrino eigenstates, as of the neutral kaon system, with the plausible breaking of lepton number conservation. In early universe, in presence of various lepton number violating processes, this oscillation might lead to neutrino-antineutrino asymmetry which resulted baryogenesis from the B-L symmetry by electro-weak sphaleron processes. On the other hand, for Majorana neutrinos, this oscillation is expected to affect the inner edge of neutrino dominated accretion disks around a compact object by influencing the neutrino sphere which controls the accretion dynamics, and then the related type-II supernova evolution and the r-process nucleosynthesis.
Costantini, H.
2012-09-15
Neutrino astrophysics offers a new possibility to observe our Universe: high-energy neutrinos, produced by the most energetic phenomena in our Galaxy and in the Universe, carry complementary (if not exclusive) information about the cosmos: this young discipline extends in fact the conventional astronomy beyond the usual electromagnetic probe. The weak interaction of neutrinos with matter allows them to escape from the core of astrophysical objects and in this sense they represent a complementary messenger with respect to photons. However, their detection on Earth due to the small interaction cross section requires a large target mass. The aim of this article is to review the scientific motivations of the high-energy neutrino astrophysics, the detection principles together with the description of a running apparatus, the experiment ANTARES, the performance of this detector with some results, and the presentation of other neutrino telescope projects.
Neutrino induced events in the MINOS detectors
Litchfield, Reuben Phillip
2008-01-01
The MINOS experiment is designed to study neutrino oscillations. It uses an accelerator generated beam of neutrinos and two detectors, the smaller at a distance of 1km and the larger at 735 km. By comparing the spectrum and flavour composition of the beam at the two detectors precise determinations of the oscillation parameters are possible. This thesis concentrates on the analysis of data from the larger Far Detector. By studying the spectrum of neutral current events it is possible to look for evidence of non-interacting 'sterile' neutrinos. The thesis describes how events are selected for this analysis, and a method for discriminating between charged current and neutral current events. The systematic uncertainties resulting from these cuts are evaluated. Several techniques for using Near Detector data to eliminate systematic uncertainties in the predicted Far Detector spectrum are compared. An oscillation analysis, based on the first year of MINOS data, uses the selected events to make a measurement of f{sub s}, the fraction of unseen neutrinos that are sterile. The measured value is f_{s} = 0.07^{+0.32} at 68%C.L., and is consistent with the standard three-neutrino picture, which has no sterile neutrino.
Searches for ultra-high energy neutrinos at the Pierre Auger observatory
Alvarez-Muñiz, Jaime
2015-07-15
Neutrinos in the sub-EeV energy range and above can be detected and identified with the Surface Detector array of the Pierre Auger Observatory. The identification can be efficiently done for neutrinos of all flavours interacting in the atmosphere, typically above 60° (downward-going), as well as for “Earth-skimming” neutrino interactions in the case of tau neutrinos (upward-going). Three sets of identification criteria were designed to search for downward-going neutrinos in the zenith angle bins 60° − 75° and 75° − 90° as well as for upward-going neutrinos. The three searches have been recently combined, providing, in the absence of candidates in data from 1 January 04 until 31 December 12, a stringent limit to the diffuse flux of ultra-high energy neutrinos.
Near maximal atmospheric neutrino mixing in neutrino mass models with two texture zeros
NASA Astrophysics Data System (ADS)
Dev, S.; Gautam, R. R.; Singh, Lal; Gupta, Manmohan
2014-07-01
The implications of a large value of the effective Majorana neutrino mass for a class of two texture zero neutrino mass matrices have been studied in the flavor basis. It is found that these textures predict a near maximal atmospheric neutrino mixing angle in the limit of a large effective Majorana neutrino mass. It is noted that this prediction is independent of the values of solar and reactor neutrino mixing angles. We present the symmetry realization of these textures using the discrete cyclic group Z3. It is found that the texture zeros realized in this work remain stable under renormalization group running of the neutrino mass matrix from the seesaw scale to the electroweak scale, at one-loop level.
Is the Higgs boson composed of neutrinos?
Krog, Jens; Hill, Christopher T.
2015-11-09
We show that conventional Higgs compositeness conditions can be achieved by the running of large Higgs-Yukawa couplings involving right-handed neutrinos that become active at ~1013–1014 GeV. Together with a somewhat enhanced quartic coupling arising by a Higgs portal interaction to a dark matter sector, we can obtain a Higgs boson composed of neutrinos. Furthermore, this is a “next-to-minimal” dynamical electroweak symmetry breaking scheme.
Is the Higgs boson composed of neutrinos?
Krog, Jens; Hill, Christopher T.
2015-11-09
We show that conventional Higgs compositeness conditions can be achieved by the running of large Higgs-Yukawa couplings involving right-handed neutrinos that become active at ~10^{13}–10^{14} GeV. Together with a somewhat enhanced quartic coupling arising by a Higgs portal interaction to a dark matter sector, we can obtain a Higgs boson composed of neutrinos. Furthermore, this is a “next-to-minimal” dynamical electroweak symmetry breaking scheme.
Exact methods for self interacting neutrinos
Pehlivan, Y.; Balantekin, A. B.; Kajino, Toshitaka
2014-06-24
The effective many-body Hamiltonian which describes vacuum oscillations and self interactions of neutrinos in a two flavor mixing scheme under the single angle approximation has the same dynamical symmetries as the well known BCS pairing Hamiltonian. These dynamical symmetries manifest themselves in terms of a set of constants of motion and can be useful in formulating the collective oscillation modes in an intuitive way. In particular, we show that a neutrino spectral split can be simply viewed as an avoided level crossing between the eigenstates of a mean field Hamiltonian which includes a Lagrange multiplier in order to fix the value of an exact many-body constant of motion. We show that the same dynamical symmetries also exist in the three neutrino mixing scheme by explicitly writing down the corresponding constants of motion.
Dynamical flavor origin of ZN symmetries
NASA Astrophysics Data System (ADS)
Sierra, D. Aristizabal; Dhen, Mikaël; Fong, Chee Sheng; Vicente, Avelino
2015-05-01
Discrete Abelian symmetries (ZN ) are a common "artifact" of beyond the standard model physics models. They provide different avenues for constructing consistent scenarios for lepton and quark mixing patterns, radiative neutrino mass generation as well as dark matter stabilization. We argue that these symmetries can arise from the spontaneous breaking of the Abelian U (1 ) factors contained in the global flavor symmetry transformations of the gauge-invariant kinetic Lagrangian. This will be the case provided the ultraviolet completion responsible for the Yukawa structure involves scalar fields carrying nontrivial U (1 ) charges. Guided by minimality criteria, we demonstrate the viability of this approach with two examples: first, we derive the "scotogenic" model Lagrangian, and second, we construct a setup where the spontaneous symmetry-breaking pattern leads to a Z3 symmetry which enables dark matter stability as well as neutrino mass generation at the two-loop order. This generic approach can be used to derive many other models, with residual ZN or ZN1×⋯×ZNk symmetries, establishing an intriguing link between flavor symmetries, neutrino masses and dark matter.
Charged Neutrinos and Atoms in the Standard Model
NASA Astrophysics Data System (ADS)
Takasugi, E.; Tanaka, M.
1992-03-01
The possibility of the charge quantization in the standard model is examined in the absence of the ``generation as copies'' rule. It is shown that neutrinos and atoms can have mini-charges, while neutron is neutral. If a triplet Higgs boson is introduced, neutrinos have masses. Two neutrinos form a Konopinski-Mahmoud Dirac particle and the other becomes a Majorana particle due to the hidden local anomaly free U(1) symmetry.
Collective Neutrino Oscillations in two dimensions
NASA Astrophysics Data System (ADS)
Shalgar, Shashank; Abbar, Sajad; Duan, Huaiyu
2015-10-01
The modification of neutrino flavor oscillation probabilities in the presence of ambient neutrino gas is non-linear in nature. This leads to interesting phenomenology that is not well understood. In this paper we study the effect of removing spatial symmetry in a simplified two dimensional toy model. We focus on the linear stability analysis of the problem and note the presence of instability in both hierarchies. We also note significant modification of neutrino oscillation probabilities due to presence of ambient matter. The presence of spurious oscillations makes the study of the problem using numerical simulations very challenging. DE-SC0008142.
Flavour changing Z ' signals in a 6D inspired model
NASA Astrophysics Data System (ADS)
Frère, Jean-Marie; Libanov, Maxim; Mollet, Simon; Troitsky, Sergey
2016-06-01
We consider the phenomenology of new neutral gauge bosons with flavour non-diagonal couplings to fermions, inherent in 6D models explaining successfully the hierarchy of masses as well as the mixing for quarks, charged leptons and neutrinos (this model can in particular be credited with the correct prediction of the neutrino mixing angle θ 13). We present a general relation between masses of new gauge bosons and their couplings to fermions. We show that in the current realization of the model, the new heavy bosons are unreachable at LHC but argue why the constraint could be relaxed in the context of a different realization. In view of a more systematic study, we use an effective model inspired by the above to relate directly rare meson decays to possible LHC observations. In terms of effective Lagrangians, this can be seen as the introduction in the model of only one overall scaling parameter to extend our approach without modifying the 4D (gauge) structure.
Effective Theories of Neutrino Masses
NASA Astrophysics Data System (ADS)
Gavela, M. B.
2013-02-01
The importance of improving the bounds on those effective non-standard neutrino interactions (NSI) which are a signal of all fermionic-mediated Seesaws is stressed: they are revealed as non-unitarity of the leptonic mixing matrix, and at experimental reach for seesaw scales ⩽ O(TeV). Some recent activity in the literature on other - theoretically not well motivated - ill-constrained NSI are also summarized. Furthermore, the status of the simplest Seesaw scenario with only two heavy neutrinos is reviewed. This model happens to be a explicit realization of the effective Minimal Flavour Violation approach. We derive the scalar potential for the fields whose background values are the Yukawa couplings of that model, and explore its minima. The Majorana character plays a distinctive role: the minimum of the potential allows for large mixing angles - in contrast to the simplest quark case - and predicts a maximal Majorana phase. This points in turn to a strong correlation between neutrino mass hierarchy and mixing pattern.
Flavor structure in D-brane models: Majorana neutrino masses
NASA Astrophysics Data System (ADS)
Hamada, Yuta; Kobayashi, Tatsuo; Uemura, Shohei
2014-05-01
We study the flavor structure in intersecting D-brane models. We study anomalies of the discrete flavor symmetries. We analyze the Majorana neutrino masses, which can be generated by D-brane instanton effects. It is found that a certain pattern of mass matrix is obtained and the cyclic permutation symmetry remains unbroken. As a result, trimaximal mixing matrix can be realized if Dirac neutrino mass and charged lepton mass matrices are diagonal.
Non-Abelian family symmetries as portals to dark matter
NASA Astrophysics Data System (ADS)
de Medeiros Varzielas, I.; Fischer, O.
2016-01-01
Non-Abelian family symmetries offer a very promising explanation for the flavour structure in the Standard Model and its extensions. We explore the possibility that dark matter consists in fermions that transform under a family symmetry, such that the visible and dark sector are linked by the familons - Standard Model gauge singlet scalars, responsible for spontaneously breaking the family symmetry. We study three representative models with non-Abelian family symmetries that have been shown capable to explain the masses and mixing of the Standard Model fermions.
Flavour Chemistry of Chicken Meat: A Review
Jayasena, Dinesh D.; Ahn, Dong Uk; Nam, Ki Chang; Jo, Cheorun
2013-01-01
Flavour comprises mainly of taste and aroma and is involved in consumers’ meat-buying behavior and preferences. Chicken meat flavour is supposed to be affected by a number of ante- and post-mortem factors, including breed, diet, post-mortem ageing, method of cooking, etc. Additionally, chicken meat is more susceptible to quality deterioration mainly due to lipid oxidation with resulting off-flavours. Therefore, the intent of this paper is to highlight the mechanisms and chemical compounds responsible for chicken meat flavour and off-flavour development to help producers in producing the most flavourful and consistent product possible. Chicken meat flavour is thermally derived and the Maillard reaction, thermal degradation of lipids, and interaction between these 2 reactions are mainly responsible for the generation of flavour and aroma compounds. The reaction of cysteine and sugar can lead to characteristic meat flavour specially for chicken and pork. Volatile compounds including 2-methyl-3-furanthiol, 2-furfurylthiol, methionol, 2,4,5-trimethyl-thiazole, nonanol, 2-trans-nonenal, and other compounds have been identified as important for the flavour of chicken. However 2-methyl-3-furanthiol is considered as the most vital chemical compound for chicken flavour development. In addition, a large number of heterocyclic compounds are formed when higher temperature and low moisture conditions are used during certain cooking methods of chicken meat such as roasting, grilling, frying or pressure cooking compared to boiled chicken meat. Major volatile compounds responsible for fried chicken are 3,5-dimethyl-1,2,4-trithiolanes, 2,4,6-trimethylperhydro-1,3,5-dithiazines, 3,5-diisobutyl-1,2,4-trithiolane, 3-methyl-5-butyl-1,2,4-trithiolane, 3-methyl-5-pentyl-1,2,4-trithiolane, 2,4-decadienal and trans-4,5-epoxy-trans-2-decenal. Alkylpyrazines were reported in the flavours of fried chicken and roasted chicken but not in chicken broth. The main reason for flavour deterioration
NASA Astrophysics Data System (ADS)
Kopp, J.; Machado, P. A. N.; Maltoni, M.; Schwetz, T.
2016-06-01
We characterize statistically the indications of a presence of one or more light sterile neutrinos from MiniBooNE and LSND data, together with the reactor and gallium anomalies, in the global context. The compatibility of the aforementioned signals with null results from solar, atmospheric, reactor, and accelerator experiments is evaluated. We conclude that a severe tension is present in the global fit, and therefore the addition of eV-scale sterile neutrinos does not satisfactorily explain the anomalies.
Detecting Solar Neutrino Flares and Flavors
NASA Astrophysics Data System (ADS)
Fargion, D.
2004-06-01
Most power-full solar flare as the ones occurred on 23th February 1956, September 29th 1989 and recent ones occurred on 28th October, on 2nd-4th and 13th November 2003 have been respectively recorded by Radio-X- and Cosmic Rays detectors. These flares took place most in the open or in the edge and in the hidden solar disk (as for the September 29th, 1989 beyond 105Wo and for last November 2003 flare events). The 4th November event was the most powerful X event in the highest known rank category X28. The observed and estimated total flare energy E = 1031-1033 erg should be a source also of a prompt secondary neutrino burst originated, by proton-proton-pion production on the sun itself; a more delayed and spread neutrino flux signal arise later on the terrestrial atmosphere. These first earliest prompt solar neutrino burst might be already recorde, in a few neutrino clustered events, in largest neutrino underground detectors as Super-Kamiokande one, in time correlation with the sharp X-Radio flare onset. Our first estimate at the Super-Kamiokande II Laboratory is found to be a few (1-5) events. Their discover (or absence) should constrains the solar flare acceleration, energetic and its inner environment. Any large neutrino flare event might even verify the expected neutrino flavour mixing leading to comparable electron- muon event as well as a comparable energy fluence and spectra. Rare Tau appearence by neutrino muon into tau conversion might also arise.
Flavour Physics and Implication for New Phenomena
NASA Astrophysics Data System (ADS)
Isidori, Gino
2016-10-01
Flavour physics represents one of the most interesting and, at the same time, less understood sector of the Standard Theory. On the one hand, the peculiar pattern of quark and lepton masses, and their mixing angles, may be the clue to some new dynamics occurring at high-energy scales. On the other hand, the strong suppression of flavour-changing neutral-current processes, predicted by the Standard Theory and confirmed by experiments, represents a serious challenge to extend the Theory. This article reviews both these aspects of flavour physics from a theoretical perspective.
NASA Astrophysics Data System (ADS)
Sobków, W.; Błaut, A.
2016-05-01
In this paper, we analyze the theoretically possible scenario beyond the standard model in order to show how the presence of the exotic scalar, tensor, {V}+{A} weak interactions in addition to the standard vector-axial ({V}-{A}) ones may help to distinguish the Dirac from Majorana neutrinos in the elastic scattering of an (anti)neutrino beam off the unpolarized electrons in the relativistic limit. We assume that the incoming (anti)neutrino beam comes from the polarized muon decay at rest and is the left-right chiral superposition with assigned direction of the transversal spin polarization with respect to the production plane. Our analysis is carried out for the flavour (current) neutrino eigenstates. It means that the transverse neutrino polarization estimates are the same both for the Dirac and Majorana cases. We display that the azimuthal asymmetry in the angular distribution of recoil electrons is generated by the interference terms between the standard and exotic couplings, which are proportional to the transversal (anti)neutrino spin polarization and independent of the neutrino mass. This asymmetry for the Majorana neutrinos is larger than for the Dirac ones. We also indicate the possibility of utilizing the azimuthal asymmetry measurements to search for the new CP-violating phases. Our study is based on the assumption that the possible detector (running for 1 year) has the shape of a flat circular ring, while the intense neutrino source is located in the centre of the ring and polarized perpendicularly to the ring. In addition, the large low-threshold, real-time detector is able to measure with a high resolution both the polar angle and the azimuthal angle of outgoing electron momentum. Our analysis is model-independent and consistent with the current upper limits on the non-standard couplings.
Signatures of neutrino cooling in the SN1987A scenario
NASA Astrophysics Data System (ADS)
Fraija, N.; Bernal, C. G.; Hidalgo-Gaméz, A. M.
2014-07-01
The neutrino signal from SN1987A confirmed the core-collapse scenario and the possible formation of a neutron star. Although this compact object has eluded all observations, theoretical and numerical developments have allowed a glimpse of the fate of it. In particular, a hypercritical accretion model has been proposed to forecast the accretion of ˜0.15 M⊙ in two hours and the subsequent submergence of the magnetic field in the newborn neutron star. In this paper, we revisit Chevalier's model in a numerical framework, focusing on the neutrino cooling effect on the supernova fall-back dynamics. For that, using a customized version of the FLASH code, we carry out numerical simulations of the accretion of matter on to the newborn neutron star in order to estimate the size of the neutrino-sphere, the emissivity and luminosity of neutrinos. As a signature of this phase, we estimate the neutrinos expected on SK neutrino experiment and their flavour ratios. This is academically important because, although currently it was very difficult to detect 1.46 thermal neutrinos and their oscillations, these fingerprints are the only viable and reliable way to confirm the hypercritical phase. Perhaps new techniques for detecting neutrino oscillations will arise in the near future allowing us to confirm our estimates.
Zhu, Guangyong; Xiao, Zuobing; Zhou, Rujun; Feng, Nienie
2015-07-01
Flavour plays an important role and has been widely used in many products. Usually, the components of flavour are volatile and the sensory perception can be changed as a result of volatilization, heating, oxidation and chemical interactions. Encapsulation can prevent the loss of volatile aromatic ingredients, provide protection and enhance the stability of the core materials. This work concentrated on production of a transparent lavender flavour nanocapsule aqueous solution. The results showed that a transparent lavender flavour microcapsule aqueous solution can be produced using hydroxypropyl-β-cyclodextrin (HP-β-CD) as wall material. The combination and interaction of flavour and wall materials were investigated by pyrolysis. Pyrolysis characteristics and kinetic parameters of the flavour nanocapsule were determined. During thermal degradation of blank HP-β-CD and flavour-HP-β-CD inclusion complex, three main stages can be distinguished. Due to the vaporization of lavender flavour encapsulated in HP-β-CD, the thermogravimetric (TG) curve of blank HP-β-CD shows a leveling-off from room temperature to 269 °C, while the TG curve of flavour-HP-β-CD inclusion complex is downward sloping in this temperature range. The kinetic parameters are helpful in understanding the mechanism of molecular recognition between hosts and guests. PMID:26139932
Phenomenological studies of neutrino physics
NASA Astrophysics Data System (ADS)
Liao, Jiajun
In this thesis, we studied the phenomenological results of several classes of neutrino models. We begin with an investigation of the effect of small perturbations on the mu-tau symmetrical models. We found that since m 1 and m2 are nearly degenerate, mu-tau symmetry mixing scenarios are able to explain the experimental data with about the same size perturbation for most values of &theta12. This suggests that the underlying unperturbed mixing need not have &theta12 close to the experimentally preferred value. Then we studied a simple case of type I seesaw model that have four texture zeros in the Yukawa couplings matrix, which is equivalent to a single texture or cofactor zero for an off-diagonal element of the light neutrino mass matrix M in the context of low energy phenomenology. Furthermore we studied a variety of neutrino models that have one or two texture and/or cofactor zeros. We determined the constraints in the space of the CP phase and lightest neutrino mass using a global fit to neutrino parameters, including recent data on &theta 13. We used leptogenesis to further constrain the parameter space for the seesaw models with four zeros in the Yukawa matrix, and made predictions on neutrinoless double beta decay for these models. Finally we showed that any neutrino model with a homogeneous relationship among elements of the light neutrino mass matrix with one mass hierarchy predicts oscillation parameters and Majorana phases similar to those of models with the same homogeneous relationship among cofactors of the mass matrix with the opposite mass hierarchy if the lightest mass is not too small, e.g., less than about 20 meV. This general result applies to texture and/or cofactor zero models, scaling models, and models that have two equal mass matrix elements or cofactors, e.g. mu-tau symmetric models.
Predictive model for radiatively induced neutrino masses and mixings with dark matter.
Gustafsson, Michael; No, Jose M; Rivera, Maximiliano A
2013-05-24
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. PMID:23745861
Predictive model for radiatively induced neutrino masses and mixings with dark matter.
Gustafsson, Michael; No, Jose M; Rivera, Maximiliano A
2013-05-24
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.
Moubayidin, Laila; Østergaard, Lars
2015-09-01
985 I. 985 II. 986 III. 987 IV. 988 V. 989 989 References 989 SUMMARY: The development of multicellular organisms depends on correct establishment of symmetry both at the whole-body scale and within individual tissues and organs. Setting up planes of symmetry must rely on communication between cells that are located at a distance from each other within the organism, presumably via mobile morphogenic signals. Although symmetry in nature has fascinated scientists for centuries, it is only now that molecular data to unravel mechanisms of symmetry establishment are beginning to emerge. As an example we describe the genetic and hormonal interactions leading to an unusual bilateral-to-radial symmetry transition of an organ in order to promote reproduction.
WIMP abundance and lepton (flavour) asymmetry
Stuke, Maik; Schwarz, Dominik J.; Starkman, Glenn E-mail: dschwarz@physik.uni-bielefeld.de
2012-03-01
We investigate how large lepton asymmetries affect the evolution of the early universe at times before big bang nucleosynthesis and in particular how they influence the relic density of WIMP dark matter. In comparison to the standard calculation of the relic WIMP abundance we find a decrease, depending on the lepton flavour asymmetry. We find an effect of up to 20 per cent for lepton flavour asymmetries l{sub f} = O(0.1)
New trends in beer flavour compound analysis.
Andrés-Iglesias, Cristina; Montero, Olimpio; Sancho, Daniel; Blanco, Carlos A
2015-06-01
As the beer market is steadily expanding, it is important for the brewing industry to offer consumers a product with the best organoleptic characteristics, flavour being one of the key characteristics of beer. New trends in instrumental methods of beer flavour analysis are described. In addition to successfully applied methods in beer analysis such as chromatography, spectroscopy, nuclear magnetic resonance, mass spectrometry or electronic nose and tongue techniques, among others, sample extraction and preparation such as derivatization or microextraction methods are also reviewed.
Generalized CP symmetries in Δ(27) flavor models
NASA Astrophysics Data System (ADS)
Nishi, C. C.
2013-08-01
We classify explicitly all the possible generalized CP symmetries that are definable in Δ(27) flavor models. In total, only 12 transformations are possible. We also show interesting consequences of considering some of them as residual symmetries of the neutrino sector.
SNO: solving the mystery of the missing neutrinos
Jelley, Nick; Poon, Alan
2007-03-30
The end of an era came on 28 November 2006 when the Sudbury Neutrino Observatory (SNO) finally stopped data-taking after eight exciting years of discoveries. During this time the Observatory saw evidence that neutrinos, produced in the fusion of hydrogen in the solar core, change flavour while passing through the Sun on their way to the Earth. This observation explained the longstanding puzzle as to why previous experiments had seen fewer solar neutrinos than predicted and confirmed that these elusive particles have mass. Solar neutrinos were first detected in Ray Davis's radiochemical experiment in 1967, for which discovery he shared the 2002 Nobel Prize in Physics. Surprisingly he found only about a third of the number predicted from models of the Sun's output. This deficit, the so-called Solar Neutrino Problem, was confirmed by Kamiokande-II while other experiments saw related deficits of solar neutrinos. A possible explanation for this deficit, suggested by Gribov and Pontecorvo in 1969, was that some of the electron-type neutrinos, which are produced in the Sun, had ''oscillated'' into neutrinos that could not be detected in the Davis detector. The oscillation mechanism requires that neutrinos have non-zero mass. The unique advantage, which was pointed out by the late Herb Chen in 1985, of using heavy water (D{sub 2}O) to detect the neutrinos from {sup 8}B decays in the solar fusion process is that it enables both the number of electron-type and of all types of neutrinos to be measured. A comparison of the flux of electron-type neutrinos to that of all flavours could then reveal whether flavour transformation is the cause of the solar neutrino deficit. In heavy water neutrinos of all types can break a deuteron apart into its constituent proton and neutron (neutral-current reaction), while only electron-type neutrinos can change the deuteron into two protons and release an electron (charged-current reaction). SNO was designed by scientists from Canada, the USA
Presymmetry in the Standard Model with adulterated Dirac neutrinos
NASA Astrophysics Data System (ADS)
Matute, Ernesto A.
2015-08-01
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.
Hierarchical majorana neutrinos from democratic mass matrices
NASA Astrophysics Data System (ADS)
Yang, Masaki J. S.
2016-09-01
In this paper, we obtain the light neutrino masses and mixings consistent with the experiments, in the democratic texture approach. The essential ansatz is that νRi are assumed to transform as "right-handed fields" 2R +1R under the S3L ×S3R symmetry. The symmetry breaking terms are assumed to be diagonal and hierarchical. This setup only allows the normal hierarchy of the neutrino mass, and excludes both of inverted hierarchical and degenerated neutrinos. Although the neutrino sector has nine free parameters, several predictions are obtained at the leading order. When we neglect the smallest parameters ζν and ζR, all components of the mixing matrix UPMNS are expressed by the masses of light neutrinos and charged leptons. From the consistency between predicted and observed UPMNS, we obtain the lightest neutrino masses m1 = (1.1 → 1.4) meV, and the effective mass for the double beta decay
Neutrino masses, neutrino oscillations, and cosmological implications
NASA Technical Reports Server (NTRS)
Stecker, F. W.
1982-01-01
Theoretical concepts and motivations for considering neutrinos having finite masses are discussed and the experimental situation on searches for neutrino masses and oscillations is summarized. The solar neutrino problem, reactor, deep mine and accelerator data, tri decay experiments and double beta-decay data are considered and cosmological implications and astrophysical data relating to neutrino masses are reviewed. The neutrino oscillation solution to the solar neutrino problem, the missing mass problem in galaxy halos and galaxy cluster galaxy formation and clustering, and radiative neutrino decay and the cosmic ultraviolet background radiation are examined.
Gava, J.
2010-05-01
We present the consequences of a large radiative correction term coming from Supersymmetry (SUSY) upon the electron neutrino fluxes streaming off a core-collapse supernova using a 3-flavour neutrino-neutrino interaction code. We explore the interplay between the neutrino-neutrino interaction and the effects of the resonance associated with the μ−τ neutrino index of refraction. We find that sizeable effects may be visible in the flux on Earth and, consequently, on the number of events upon the energy signal of electron neutrinos in a liquid argon detector. Such effects could lead to a probe for Beyond Standard Model (BSM) physics and, ideally, to constraints in the SUSY parameter space.
Nonzero θ13 and CP violation in a model with A4 flavor symmetry
NASA Astrophysics Data System (ADS)
Ahn, Y. H.; Kang, Sin Kyu
2012-11-01
Motivated by recent observations of nonzero θ13 from the Daya Bay and RENO experiments, we propose a renormalizable neutrino model with A4 discrete symmetry accounting for deviations from the tri-bimaximal mixing pattern of the neutrino mixing matrix indicated by neutrino oscillation data. In the model, the light neutrino masses can be generated by radiative corrections, and we show how the light neutrino mass matrix can be diagonalized by the Pontecorvo-Maki-Nakagawa-Sakata mixing matrix whose entries are determined by the current neutrino data, including the Daya Bay result. We show that the origin of the deviations from the tri-bimaximal mixing is nondegeneracy of the neutrino Yukawa coupling constants, and unremovable CP phases in the neutrino Yukawa matrix give rise to both low energy CP violation measurable from neutrino oscillation and high energy CP violation.
Renormalization of the neutrino mass matrix
NASA Astrophysics Data System (ADS)
Chiu, S. H.; Kuo, T. K.
2016-09-01
In terms of a rephasing invariant parametrization, the set of renormalization group equations (RGE) for Dirac neutrino parameters can be cast in a compact and simple form. These equations exhibit manifest symmetry under flavor permutations. We obtain both exact and approximate RGE invariants, in addition to some approximate solutions and examples of numerical solutions.
Future Long-Baseline Neutrino Oscillations: View from North America
Wilson, R. J.
2015-06-01
In late 2012 the US Department of Energy gave approval for the first phase of the Long-Baseline Neutrino Experiment (LBNE), that will conduct a broad scientific program including neutrino oscillations, neutrino scattering physics, search for baryon violation, supernova burst neutrinos and other related astrophysical phenomena. The project is now being reformulated as an international facility hosted by the United States. The facility will consist of an intense neutrino beam produced at Fermi National Accelerator Laboratory (Fermilab), a highly capable set of neutrino detectors on the Fermilab campus, and a large underground liquid argon time projection chamber at Sanford Underground Research Facility (SURF) in South Dakota 1300 km from Fermilab. With an intense beam and massive far detector, the experimental program at the facility will make detailed studies of neutrino oscillations, including measurements of the neutrino mass hierarchy and Charge-Parity symmetry violation, by measuring neutrino and anti-neutrino mixing separately. At the near site, the high-statistics neutrino scattering data will allow for many cross section measurements and precision tests of the Standard Model. This presentation will describe the configuration developed by the LBNE collaboration, the broad physics program, and the status of the formation of the international facility.
Future long-baseline neutrino oscillations: View from North America
Wilson, Robert J.
2015-07-15
In late 2012 the US Department of Energy gave approval for the first phase of the Long-Baseline Neutrino Experiment (LBNE) that will conduct a broad scientific program including neutrino oscillations, neutrino scattering physics, search for baryon violation, supernova burst neutrinos and other related astrophysical phenomena. The project is now being reformulated as an international facility hosted by the United States. The facility will consist of an intense neutrino beam produced at Fermi National Accelerator Laboratory (Fermilab), a highly capable set of neutrino detectors on the Fermilab campus, and a large underground liquid argon time projection chamber at Sanford Underground Research Facility (SURF) in South Dakota 1300 km from Fermilab. With an intense beam and massive far detector, the experimental program at the facility will make detailed studies of neutrino oscillations, including measurements of the neutrino mass hierarchy and Charge-Parity symmetry violation, by measuring neutrino and anti-neutrino mixing separately. At the near site, the high-statistics neutrino scattering data will allow for many cross section measurements and precision tests of the Standard Model. This presentation will describe the configuration developed by the LBNE collaboration, the broad physics program, and the status of the formation of the international facility.
Heavy Flavour results from Tevatron
Borissov, G.; /Lancaster U.
2012-06-01
The CDF and D0 experiments finalize the analysis of their full statistics collected in the p{bar p} collisions at a center-of-mass energy of {radical}s = 1.96 TeV at the Fermilab Tevatron collider. This paper presents several new results on the properties of hadrons containing heavy b- and c-quarks obtained by both collaborations. These results include the search for the rare decays B{sup 0}, B{sub s}{sup 0} {yields} {mu}{sup +}{mu}{sup -} (CDF), the study of CP asymmetry in B{sub s} {yields} J{psi}{phi} decay (CDF, D0), the measurement of the like-sign dimuon charge asymmetry (D0), the measurement of CP asymmetry in D{sup 0} {yields} K{sup +}K{sup -} and D{sup 0} {yields} {pi}{sup +}{pi}{sup -} decays (CDF), and the new measurement of the B{sub s} {yields} D{sub s}{sup (*)+} D{sub s}{sup (*)-} branching fraction (CDF). Both experiments still expect to produce more results on the properties of heavy flavours.
Neutrino dark energy in grand unified theories
Bhatt, Jitesh R.; Sarkar, Utpal; Singh, Santosh K.; Gu, P.-H.
2009-10-01
We studied a left-right symmetric model that can accommodate the neutrino dark energy ({nu}DE) proposal. The type-III seesaw mechanism is implemented to give masses to the neutrinos. After explaining the model, we study the consistency of the model by minimizing the scalar potential and obtaining the conditions for the required vacuum expectation values of the different scalar fields. This model is then embedded in an SO(10) grand unified theory and the allowed symmetry breaking scales are determined by the condition of the gauge coupling unification. Although SU(2){sub R} breaking is required to be high, its Abelian subgroup U(1){sub R} is broken in the TeV range, which can then give the required neutrino masses and predicts new gauge bosons that could be detected at LHC. The neutrino masses are studied in detail in this model, which shows that at least 3 singlet fermions are required.
A Sterile-Neutrino Search with the MINOS Experiment
Rodrigues, Philip
2010-01-01
The MINOS experiment is a long-baseline neutrino oscillation experiment in the the NuMI beamline at Fermilab, USA. Using a near detector at 1 km distance from the neutrino production target, and a far detector at 735 km from the target, it is designed primarily to measure the disappearance of muon neutrinos. This thesis presents an analysis using MINOS data of the possibility of oscil- lation of the neutrinos in the NuMI beam to a hypothetical sterile flavour, which would have no Standard Model couplings. Such oscillations would result in a deficit in the neutral current interaction rate in the MINOS far detector relative to the expectation derived from the near detector data. The method used to identify neutral current and charged current events in the MINOS detectors is described and a new method of predicting and fitting the far detector spectrum presented, along with the effects of systematic uncertainties on the sterile neutrino oscillation analysis. Using this analysis, the fraction f_{s} of the disappearing neutrinos that go to steriles is constrained to be below 0.15 at the 90% confidence level in the absence of electron neutrino appearance in the NuMI beam. With electron appearance at the CHOOZ limit, f_{s} < 0.41 at 90% C.L.
PREFACE: DISCRETE 2012 - Third Symposium on Prospects in the Physics of Discrete Symmetries
NASA Astrophysics Data System (ADS)
Branco, G. C.; Emmanuel-Costa, D.; González Felipe, R.; Joaquim, F. R.; Lavoura, L.; Palomares-Ruiz, S.; Rebelo, M. N.; Romão, J. C.; Silva, J. P.
2013-07-01
The Third Symposium on Prospects in the Physics of Discrete Symmetries (DISCRETE 2012) was held at Instituto Superior Técnico, Portugal, from 3-7 December 2012 and was organised by Centro de Física Teórica de Partículas (CFTP) of Instituto Superior Técnico, Universidade Técnica de Lisboa. This is the sequel to the Symposia that was successfully organised in Valéncia in 2008 and in Rome in 2010. The topics covered included: T, C, P, CP symmetries CPT symmetry, decoherence, Lorentz symmetry breaking Discrete symmetries and models of flavour mixing Baryogenesis, leptogenesis Neutrino physics Electroweak symmetry breaking and physics beyond the Standard Model Accidental symmetries (B, L conservation) Experimental prospects at LHC Dark matter searches Super flavour factories, and other new experimental facilities The Symposium was organised in plenary sessions with a total of 24 invited talks, and parallel sessions with a total of 70 talks, including both invited and selected contributions from the submitted abstracts. The speakers of the plenary sessions were: Ignatios Antoniadis, Abdelhak Djouadi, Rabindra Mohapatra, André Rubbia, Alexei Yu Smirnov, José Bernabéu, Marco Cirelli, Apostolos Pilaftsis, Antonio Di Domenico, Robertus Potting, João Varela, Frank Rathmann, Michele Gallinaro, Dumitru Ghilencea, Neville Harnew, John Walsh, Patrícia Conde Muíño, Juan Aguilar-Saavedra, Nick Mavromatos, Ulrich Nierste, Ferruccio Feruglio, Vasiliki Mitsou, Masanori Yamauchi, and Marcello Giorgi. The Symposium was attended by about 140 participants. Among the social events, there was a social dinner in the historical Associação Comercial de Lisboa, which included a musical performance of 'Fado', the traditional music from Lisbon. The next symposium of the series will be organised by King's College, London University, UK, from 1-5 December 2014. Guest Editors G C Branco, D Emmanuel-Costa, R González Felipe, F R Joaquim, L Lavoura, S Palomares-Ruiz, M N Rebelo, J C
Neutrino flavor pendulum in both mass hierarchies
NASA Astrophysics Data System (ADS)
Raffelt, Georg; Seixas, David de Sousa
2013-08-01
We construct a simple example for self-induced flavor conversion in dense neutrino gases, showing new solutions that violate the symmetries of initial conditions. Our system consists of two opposite momentum modes 1 and 2, each initially occupied with equal densities of νe and ν¯e. Restricting solutions to symmetry under 1↔2 allows for the usual bimodal instability (“flavor pendulum”) in the inverted neutrino mass hierarchy and stability (no self-induced flavor conversion) in the normal hierarchy (NH). Lifting this symmetry restriction allows for a second pendulumlike solution that occurs in NH, where the modes 1 and 2 swing in opposite directions in flavor space. Any small deviation from 1-2 symmetry in the initial condition triggers the new instability in NH. This effect corresponds to the recently identified multi-azimuth angle instability of supernova neutrino fluxes. Both cases show explicitly that solutions of the equations of collective flavor oscillations need not inherit the symmetries of initial conditions, although this has been universally assumed.
Neutrino refraction by the cosmic neutrino background
NASA Astrophysics Data System (ADS)
Díaz, J. S.; Klinkhamer, F. R.
2016-03-01
We have determined the dispersion relation of a neutrino test particle propagating in the cosmic neutrino background. Describing the relic neutrinos and antineutrinos from the hot big bang as a dense medium, a matter potential or refractive index is obtained. The vacuum neutrino mixing angles are unchanged, but the energy of each mass state is modified. Using a matrix in the space of neutrino species, the induced potential is decomposed into a part which produces signatures in beta-decay experiments and another part which modifies neutrino oscillations. The low temperature of the relic neutrinos makes a direct detection extremely challenging. From a different point of view, the identified refractive effects of the cosmic neutrino background constitute an ultralow background for future experimental studies of nonvanishing Lorentz violation in the neutrino sector.
Predictive model of radiative neutrino masses
NASA Astrophysics Data System (ADS)
Babu, K. S.; Julio, J.
2014-03-01
We present a simple and predictive model of radiative neutrino masses. It is a special case of the Zee model which introduces two Higgs doublets and a charged singlet. We impose a family-dependent Z4 symmetry acting on the leptons, which reduces the number of parameters describing neutrino oscillations to four. A variety of predictions follow: the hierarchy of neutrino masses must be inverted; the lightest neutrino mass is extremely small and calculable; one of the neutrino mixing angles is determined in terms of the other two; the phase parameters take CP-conserving values with δCP=π; and the effective mass in neutrinoless double beta decay lies in a narrow range, mββ=(17.6-18.5) meV. The ratio of vacuum expectation values of the two Higgs doublets, tanβ, is determined to be either 1.9 or 0.19 from neutrino oscillation data. Flavor-conserving and flavor-changing couplings of the Higgs doublets are also determined from neutrino data. The nonstandard neutral Higgs bosons, if they are moderately heavy, would decay dominantly into μ and τ with prescribed branching ratios. Observable rates for the decays μ →eγ and τ→3μ are predicted if these scalars have masses in the range of 150-500 GeV.
A model of massive neutrinos with a conserved lepton number
NASA Astrophysics Data System (ADS)
Ecker, G.; Grimus, W.; Gronau, M.
1987-01-01
We consider a left-right symmetric model with three generations and with the standard assignments of fermion and scalar fields. The left-right symmetry gives rise to a unique conserved lepton number which is of the Zel'dovich-Konopinski-Mahmoud type. The neutrino mass matrix yields one Dirac and one Majorana neutrino, both in the light and in the heavy sector. Up to small mixings with right-handed neutrinos, the left-handed ν e and ν τ combine to the light Dirac neutrino whereas ν μ is the light Majoranan neutrino. With a right-handed scale in the TeV range all light neutrino lepton masses. Phenomenological consequences of the model are discussed. charged lepton masses. Phenomenological consequences of the model are discussed.
On the Sensitivity of Neutrino Telescopes to a Modified Dispersion Relation
Bustamante, M.; Gago, A. M.; Bazo, J. L.; Miranda, O. G.
2008-07-02
We consider a modified dispersion relation and its effect on the flavour ratios of high-energy neutrinos originated at distant astrophysical sources such as active galactic nuclei. This dispersion relation arise naturally in different new physics (NP) effects such as violation of CPT invariance, of the equivalence principle and of Lorentz invariance. It is a common notion in the literature that by using the flux of high-energy neutrinos expected from distant astrophysical sources, the sensitivity to possible NP effects may be improved beyond the current bounds. However, performing a realistic analysis that takes into account the expected number of events in future neutrino telescopes, we find that the average detected flavour ratios with and without the inclusion of new physics have essentially the same value, making difficult to obtain an improved bound for this type of new physics.
Neutrinos: Theory and Phenomenology
Parke, Stephen
2013-10-22
The theory and phenomenology of neutrinos will be addressed, especially that relating to the observation of neutrino flavor transformations. The current status and implications for future experiments will be discussed with special emphasis on the experiments that will determine the neutrino mass ordering, the dominant flavor content of the neutrino mass eigenstate with the smallest electron neutrino content and the size of CP violation in the neutrino sector. Beyond the neutrino Standard Model, the evidence for and a possible definitive experiment to confirm or refute the existence of light sterile neutrinos will be briefly discussed.
Flavour-Violating Gluino and Squark Decays
Hurth, Tobias; Porod, Werner; /Wurzburg U.
2010-06-11
We consider scenarios with large flavour violating entries in the squark mass matrices focusing on the mixing between second and third generation squarks. These entries govern both, flavour violating low energy observables on the one hand and squark and gluino decays on the other hand. We first discuss the constraints on the parameter space due to the recent data on B mesons from the B factories and Tevatron. We then consider flavour violating squark and gluino decays and show that they can still be typically of order 10% despite the stringent constraints from low energy data. Finally we briefly comment on the impact for searches and parameter determinations at future collider experiments such as the upcoming LHC or a future International Linear Collider.
Scientific Opportunities with the Long-Baseline Neutrino Experiment
Adams, C.; et al.,
2013-07-28
In this document, we describe the wealth of science opportunities and capabilities of LBNE, the Long-Baseline Neutrino Experiment. LBNE has been developed to provide a unique and compelling program for the exploration of key questions at the forefront of particle physics. Chief among the discovery opportunities are observation of CP symmetry violation in neutrino mixing, resolution of the neutrino mass hierarchy, determination of maximal or near-maximal mixing in neutrinos, searches for nucleon decay signatures, and detailed studies of neutrino bursts from galactic supernovae. To fulfill these and other goals as a world-class facility, LBNE is conceived around four central components: (1) a new, intense wide-band neutrino source at Fermilab, (2) a fine-grained `near' neutrino detector just downstream of the source, (3) the Sanford Underground Research Facility (SURF) in Lead, South Dakota at an optimal distance (~1300 km) from the neutrino source, and (4) a massive liquid argon time-projection chamber (LArTPC) deployed there as a 'far' detector. The facilities envisioned are expected to enable many other science opportunities due to the high event rates and excellent detector resolution from beam neutrinos in the near detector and atmospheric neutrinos in the far detector. This is a mature, well developed, world class experiment whose relevance, importance, and probability of unearthing critical and exciting physics has increased with time.
The Intermediate Neutrino Program
Adams, C.; et al.
2015-03-23
The US neutrino community gathered at the Workshop on the Intermediate Neutrino Program (WINP) at Brookhaven National Laboratory February 4-6, 2015 to explore opportunities in neutrino physics over the next five to ten years. Scientists from particle, astroparticle and nuclear physics participated in the workshop. The workshop examined promising opportunities for neutrino physics in the intermediate term, including possible new small to mid-scale experiments, US contributions to large experiments, upgrades to existing experiments, R&D plans and theory. The workshop was organized into two sets of parallel working group sessions, divided by physics topics and technology. Physics working groups covered topics on Sterile Neutrinos, Neutrino Mixing, Neutrino Interactions, Neutrino Properties and Astrophysical Neutrinos. Technology sessions were organized into Theory, Short-Baseline Accelerator Neutrinos, Reactor Neutrinos, Detector R&D and Source, Cyclotron and Meson Decay at Rest sessions.This report summarizes discussion and conclusions from the workshop.
Neutrino in standard model and beyond
NASA Astrophysics Data System (ADS)
Bilenky, S. M.
2015-07-01
After discovery of the Higgs boson at CERN the Standard Model acquired a status of the theory of the elementary particles in the electroweak range (up to about 300 GeV). What general conclusions can be inferred from the Standard Model? It looks that the Standard Model teaches us that in the framework of such general principles as local gauge symmetry, unification of weak and electromagnetic interactions and Brout-Englert-Higgs spontaneous breaking of the electroweak symmetry nature chooses the simplest possibilities. Two-component left-handed massless neutrino fields play crucial role in the determination of the charged current structure of the Standard Model. The absence of the right-handed neutrino fields in the Standard Model is the simplest, most economical possibility. In such a scenario Majorana mass term is the only possibility for neutrinos to be massive and mixed. Such mass term is generated by the lepton-number violating Weinberg effective Lagrangian. In this approach three Majorana neutrino masses are suppressed with respect to the masses of other fundamental fermions by the ratio of the electroweak scale and a scale of a lepton-number violating physics. The discovery of the neutrinoless double β-decay and absence of transitions of flavor neutrinos into sterile states would be evidence in favor of the minimal scenario we advocate here.
Neutrino decay and solar neutrino seasonal effect
NASA Astrophysics Data System (ADS)
Picoreti, R.; Guzzo, M. M.; de Holanda, P. C.; Peres, O. L. G.
2016-10-01
We consider the possibility of solar neutrino decay as a sub-leading effect on their propagation between production and detection. Using current oscillation data, we set a new lower bound to the ν2 neutrino lifetime at τ2 /m2 ≥ 7.2 ×10-4s .eV-1 at 99% C.L. Also, we show how seasonal variations in the solar neutrino data can give interesting additional information about neutrino lifetime.
Late Time Neutrino Masses, the LSND Experiment and the Cosmic Microwave Background
Chacko, Z.; Hall, Lawrence J.; Oliver, Steven J.; Perelstein, Maxim
2004-05-07
Models with low-scale breaking of global symmetries in the neutrino sector provide an alternative to the seesaw mechanism for understanding why neutrinos are light. Such models can easily incorporate light sterile neutrinos required by the LSND experiment. Furthermore, the constraints on the sterile neutrino properties from nucleosynthesis and large scale structure can be removed due to the non-conventional cosmological evolution of neutrino masses and densities. We present explicit, fully realistic supersymmetric models, and discuss the characteristic signatures predicted in the angular distributions of the cosmic microwave background.
Neutrino masses, leptogenesis, and dark matter in a hybrid seesaw model
Gu Peihong; Hirsch, M.; Valle, J. W. F.
2009-02-01
We suggest a hybrid seesaw model where relatively light right-handed neutrinos give no contribution to neutrino mass matrix due to a special symmetry. This allows their Yukawa couplings to the standard model particles to be relatively strong, so that the standard model Higgs boson can decay dominantly to a left- and a right-handed neutrino, leaving another stable right-handed neutrino as cold dark matter. In our model neutrino masses arise via the type-II seesaw mechanism, the Higgs triplet scalars being also responsible for the generation of the matter-antimatter asymmetry via the leptogenesis mechanism.
NASA Astrophysics Data System (ADS)
Mukhopadhyay, Banibrata
2007-03-01
We introduce a new effect in the neutrino oscillation phase which shows that the neutrino antineutrino oscillation is possible under gravity even if the rest masses of the corresponding eigenstates are the same. This is due to CPT violation, and is possible to demonstrate if the neutrino mass eigenstates are expressed as a combination of neutrino and antineutrino eigenstates, as of the neutral kaon system, with the plausible breaking of lepton number conservation. For Majorana neutrinos, this oscillation is expected to significantly affect the inner edge of neutrino-dominated accretion discs around compact objects by influencing the neutrino sphere which controls the accretion dynamics, and then the related type-II supernova evolution and the r-process nucleosynthesis. On the other hand, in the early universe, in the presence of various lepton number violating processes, this oscillation, we argue, might have led to neutrino asymmetry which resulted in baryogenesis from the B L symmetry by electro-weak sphaleron processes.
ERIC Educational Resources Information Center
Attanucci, Frank J.; Losse, John
2008-01-01
In a first calculus course, it is not unusual for students to encounter the theorems which state: If f is an even (odd) differentiable function, then its derivative is odd (even). In our paper, we prove some theorems which show how the symmetry of a continuous function f with respect to (i) the vertical line: x = a or (ii) with respect to the…
Zero minors of the neutrino mass matrix
Lashin, E. I.; Chamoun, N.
2008-10-01
We examine the possibility that a certain class of neutrino mass matrices, namely, those with two independent vanishing minors in the flavor basis, regardless of being invertible or not, is sufficient to describe current data. We compute generic formulas for the ratios of the neutrino masses and for the Majorana phases. We find that seven textures with two vanishing minors can accommodate the experimental data. We present an estimate of the mass matrix for these patterns. All of the possible textures can be dynamically generated through the seesaw mechanism augmented with a discrete Abelian symmetry.
SUGRA new inflation with Heisenberg symmetry
Antusch, Stefan; Cefalà, Francesco E-mail: stefan.antusch@unibas.ch
2013-10-01
We propose a realisation of ''new inflation'' in supergravity (SUGRA), where the flatness of the inflaton potential is protected by a Heisenberg symmetry. Inflation can be associated with a particle physics phase transition, with the inflaton being a (D-flat) direction of Higgs fields which break some symmetry at high energies, e.g. of GUT Higgs fields or of Higgs fields for flavour symmetry breaking. This is possible since compared to a shift symmetry, which is usually used to protect a flat inflaton potential, the Heisenberg symmetry is compatible with a (gauge) non-singlet inflaton field. In contrast to conventional new inflation models in SUGRA, where the predictions depend on unknown parameters of the Kaehler potential, the model with Heisenberg symmetry makes discrete predictions for the primordial perturbation parameters which depend only on the order n at which the inflaton appears in the effective superpotential. The predictions for the spectral index n{sub s} can be close to the best-fit value of the latest Planck 2013 results.
NASA Astrophysics Data System (ADS)
Kirilova, D.
2010-09-01
The relic neutrinos from the Big Bang or the Cosmic Neutrino Background (CNB) neutrinos are expected to be the most abundant particles in our universe after the relic photons of the Cosmic Microwave Background (CMB). They carry precious information from the early epoch when our universe was only 1 sec old. Although not yet directly detected, CNB may be revealed indirectly through cosmological observations due to their important cosmological influence. I review the cosmological role of neutrinos and the present cosmological constraints on neutrino characteristics. Namely, I discuss the impact of neutrinos in the cosmic expansion, neutrino decoupling, the role of neutrinos in the primordial production of light elements, their effect on CMB anisotropies, LSS formation, the possible neutrino contribution to the Dark Matter in the universe, leptogenesis, etc. Due to the considerable cosmological influence of neutrinos, cosmological bounds on neutrino properties from observational data exist. I review the cosmological constraints on the neutrino characteristics, such as the effective number of neutrino species, neutrino mass and mixing parameters, lepton number of the universe, gravitational clustering of neutrinos, presence of sterile neutrino, etc.
Lepton mixing and discrete symmetries
NASA Astrophysics Data System (ADS)
Hernandez, D.; Smirnov, A. Yu.
2012-09-01
The pattern of lepton mixing can emerge from breaking a flavor symmetry in different ways in the neutrino and charged lepton Yukawa sectors. In this framework, we derive the model-independent conditions imposed on the mixing matrix by the structure of discrete groups of the von Dyck type which include A4, S4, and A5. We show that, in general, these conditions lead to at least two equations for the mixing parameters (angles and CP phase δ). These constraints, which correspond to unbroken residual symmetries, are consistent with nonzero 13 mixing and deviations from maximal 2-3 mixing. For the simplest case, which leads to an S4 model and reproduces the allowed values of the mixing angles, we predict δ=(90°-120°).
Neutrino signals from electroweak bremsstrahlung in solar WIMP annihilation
Bell, Nicole F.; Brennan, Amelia J.; Jacques, Thomas D. E-mail: a.brennan@pgrad.unimelb.edu.au
2012-10-01
Bremsstrahlung of W and Z gauge bosons, or photons, can be an important dark matter annihilation channel. In many popular models in which the annihilation to a pair of light fermions is helicity suppressed, these bremsstrahlung processes can lift the suppression and thus become the dominant annihilation channels. The resulting dark matter annihilation products contain a large, energetic, neutrino component. We consider solar WIMP annihilation in the case where electroweak bremsstrahlung dominates, and calculate the resulting neutrino spectra. The flux consists of primary neutrinos produced in processes such as χχ→ν-bar νZ and χχ→ν-bar lW, and secondary neutrinos produced via the decays of gauge bosons and charged leptons. After dealing with the neutrino propagation and flavour evolution in the Sun, we consider the prospects for detection in neutrino experiments on Earth. We compare our signal with that for annihilation to W{sup +}W{sup −}, and show that, for a given annihilation rate, the bremsstrahlung annihilation channel produces a larger signal by a factor of a few.
McKeown, Bob
2015-06-01
Since the discovery of nuclear beta decay, nuclear physicists have studied the weak interaction and the nature of neutrinos. Many recent and current experiments have been focused on the elucidation of neutrino oscillations and neutrino mass. The quest for the absolute value of neutrino mass continues with higher precision studies of the tritium beta decay spectrum near the endpoint. Neutrino oscillations are studied through measurements of reactor neutrinos as a function of baseline and energy. And experiments searching for neutrinoless double beta decay seek to discover violation of lepton number and establish the Majorana nature of neutrino masses.
NASA Astrophysics Data System (ADS)
Ludhova, Livia
2016-05-01
There exist several kinds of sources emitting neutrinos in the MeV energy range. These low-energy neutrinos from different sources can be often detected by the same multipurpose detectors. The status-of-art of the field of solar neutrinos, geoneutrinos, and the search for sterile neutrino with artificial neutrino sources is provided here; other neutrino sources, as for example reactor or high-energy neutrinos, are described elsewhere. For each of these three fields, the present-day motivation and open questions, as well as the latest experimental results and future perspectives are discussed.
Methods and techniques in the research of tobacco flavour.
Podlejski, J; Olejniczak, W
1983-01-01
This paper performs possible ways of tobacco-flavour investigations which allow to identify flavour components and to settle aroma factors and correlations with organoleptic evaluation. At first, the basic methods of tobacco flavour research based on the analysis of tobacco raw material, tobacco smoke, and headspace vapours were discussed. The methods of tobacco flavour investigation being useful in evaluation of tobacco quality were also reported. Hence, the instrumental methods and sensory methods of tobacco flavour research were shown. The usability of these methods in detecting the flavour components of tobacco and tobacco smoke as well as in evaluating the tobacco quality in practice was considered. Furthermore, the methods of tobacco flavour research and flavour evaluation used in our department were given. The quality of tobacco flavour was evaluated by means of a definite interpretation of the chemical analysis of tobacco or tobacco smoke. The investigations of tobacco flavour were also carried out by a method basing on a special treatment of tobacco, which modifies the chemical composition of the raw material and at the same time the sensory properties. In this case the components being responsible for the tobacco flavour could be investigated by detailed tobacco- and tobacco-smoke analysis connected with sensory evaluation.
New development in radiative neutrino mass generation
NASA Astrophysics Data System (ADS)
Julio
2014-10-01
We present a simple and predictive model of radiative neutrino masses. It is a special case of the Zee model with a family-dependent Z4 symmetry acting on the leptons. A variety of predictions follow: The hierarchy of neutrino masses must be inverted; the lightest neutrino mass is extremely small and calculable; one of the neutrino mixing angles is determined in terms of the other two; the phase parameters take CP-conserving values with δCP = π and the effective mass in neutrinoless double beta decay lies in a narrow range, mββ =(17.6-18.5) meV. The ratio of vacuum expectation values of the two Higgs doublets, tan β, is determined to be either 1.9 or 0.19 from neutrino oscillation data. Flavor-conserving and flavor-changing couplings of the Higgs doublets are also determined from neutrino data. The non-standard neutral Higgs bosons, if they are moderately heavy, decay significantly into μ and τ with prescribed branching ratios. Observable rates for the decays μ → eγ and τ → 3μ are predicted if these scalars have masses in the range of 150-500 GeV.
Measurable neutrino mass scale in A{sub 4}xSU(5)
Antusch, S.; Spinrath, M.; King, Stephen F.
2011-01-01
We propose a supersymmetric A{sub 4}xSU(5) model of quasidegenerate neutrinos which predicts the effective neutrino mass m{sub ee} relevant for neutrinoless double beta decay to be proportional to the neutrino mass scale, thereby allowing its determination approximately independently of unknown Majorana phases. Such a natural quasidegeneracy is achieved by using A{sub 4} family symmetry (as an example of a non-Abelian family symmetry with real triplet representations) to enforce a contribution to the neutrino mass matrix proportional to the identity. Tribimaximal neutrino mixing as well as quark CP violation with {alpha}{approx_equal}90 deg. d a leptonic CP phase {delta}{sub MNS{approx_equal}}90 deg. arise from the breaking of the A{sub 4} family symmetry by the vacuum expectation values of four 'flavon' fields pointing in specific postulated directions in flavor space.
Wang, Shi-Hao; Chen, Pisin; Nam, Jiwoo; Huang, Melin E-mail: pisinchen@phys.ntu.edu.tw E-mail: phmelin@snolab.ca
2013-11-01
The flavor composition of ultra-high energy cosmic neutrinos (UHECN) carries precious information about the physical properties of their sources, the nature of neutrino oscillations and possible exotic physics involved during the propagation. Since UHECN with different incoming directions would propagate through different amounts of matter in Earth and since different flavors of charged leptons produced in the neutrino-nucleon charged-current (CC) interaction would have different energy-loss behaviors in the medium, measurement of the angular distribution of incoming events by a neutrino observatory can in principle be employed to help determine the UHECN flavor ratio. In this paper we report on our investigation of the feasibility of such an attempt. Simulations were performed, where the detector configuration was based on the proposed Askaryan Radio Array (ARA) Observatory at the South Pole, to investigate the expected event-direction distribution for each flavor. Assuming ν{sub μ}-ν{sub τ} symmetry and invoking the standard oscillation and the neutrino decay scenarios, the probability distribution functions (PDF) of the event directions are utilized to extract the flavor ratio of cosmogenic neutrinos on Earth. The simulation results are summarized in terms of the probability of flavor ratio extraction and resolution as functions of the number of observed events and the angular resolution of neutrino directions. We show that it is feasible to constrain the UHECN flavor ratio using the proposed ARA Observatory.
Probing maximal zero textures with broken cyclic symmetry in inverse seesaw
NASA Astrophysics Data System (ADS)
Samanta, Rome; Ghosal, Ambar
2016-10-01
Within the framework of inverse seesaw mechanism we investigate neutrino mass matrices invariant under cyclic symmetry (Z3) with maximal zero texture (6 zero textures). We explore two different approaches to obtain the cyclic symmetry invariant form of the constituent matrices. In the first one we consider explicit cyclic symmetry in the neutrino sector of the Lagrangian which dictates the emerged effective neutrino mass matrix (mν) to be symmetry invariant and hence leads to a degeneracy in masses. We then consider explicit breaking of the symmetry through a dimensionless parameter ɛ‧ to remove the degeneracy. It is seen that the method doesn't support the current neutrino oscillation global fit data even after considering the correction from cyclic symmetry invariant charged lepton mass matrix (ml) unless the breaking parameter is too large. In the second method, we assume the same forms of the neutrino mass matrices, however, symmetry is broken in the charged lepton sector. All the structures of the mass matrices are now dictated by an effective residual symmetry of some larger symmetry group in the Lagrangian. For illustration, we exemplify a toy model based on softly broken A4 symmetry group which leads to one of the combinations of ml, mD, MRS and μ to generate effective mν. All the emerged mass matrices predict a constraint range of the CP violating phases and atmospheric mixing angle along with an inverted hierarchical structure of the neutrino masses. Further, significant predictions on ββ 0 ν decay parameter |m11 | and the sum of the three light neutrino masses (Σimi) are also obtained.
Hypercritical accretion phase and neutrino expectation in the evolution of Cassiopeia A
NASA Astrophysics Data System (ADS)
Fraija, N.; Bernal, C. G.
2015-07-01
Cassiopeia A, the youngest supernova remnant known in the Milky Way, is one of the brightest radio sources in the sky and a unique laboratory for supernova physics. Although its compact remnant was discovered in 1999 by the Chandra X-Ray Observatory, nowadays it is widely accepted that a neutron star lies in the centre of this supernova remnant. In addition, new observations suggest that such a neutron star with a low magnetic field and evidence of a carbon atmosphere could have suffered a hypercritical accretion phase seconds after the explosion. Considering this hypercritical accretion episode, we compute the neutrino cooling effect, the number of events and neutrino flavour ratios expected on Hyper-Kamiokande Experiment. The neutrino cooling effect (the emissivity and luminosity of neutrinos) is obtained through numerical simulations performed in a customized version of the FLASH code. Based on these simulations, we forecast that the number of events expected on the Hyper-Kamiokande Experiment is around 3195. Similarly, we estimate the neutrino flavour ratios to be detected considering the neutrino effective potential due to the thermal and magnetized plasma and thanks to the envelope of the star. It is worth noting that our estimates correspond to the only trustworthy method for verifying the hypercritical phase and although this episode took place 330 years ago, at present supernova remnants with these similarities might occur thus confirming our predictions for this phase.
Dark matter from PeV physics and the neutrino sector
NASA Astrophysics Data System (ADS)
Shakya, Bibhushan; Roland, Samuel B.; Wells, James D.
2016-06-01
It is well known that the neutrino sector can provide a dark matter candidate in the form of a light sterile neutrino. This note discusses a framework that naturally leads to light (keV-GeV) sterile neutrino dark matter produced via the freeze-in mechanism: a modified, low energy seesaw with the right-handed neutrinos charged under a new symmetry broken by a PeV scale vacuum expectation value. This framework can accommodate the recently observed 3.5 keV X-ray line, while a straightforward extension, using the new symmetry and the PeV energy scale, can explain the PeV energy neutrino events at IceCube. Together, these can therefore be taken as hints of the existence of a PeV scale neutrino sector.
NASA Astrophysics Data System (ADS)
Bambhaniya, Gulab; Dev, P. S. Bhupal; Goswami, Srubabati; Mitra, Manimala
2016-04-01
We analyse in detail the scalar triplet contribution to the low-energy lepton flavour violating (LFV) and lepton number violating (LNV) processes within a TeV-scale left-right symmetric framework. We show that in both type-I and type-II seesaw dominance for the light neutrino masses, the triplet of mass comparable to or smaller than the largest right-handed neutrino mass scale can give sizeable contribution to the LFV processes, except in the quasi-degenerate limit of light neutrino masses, where a suppression can occur due to cancellations. In particular, a moderate value of the heaviest neutrino to scalar triplet mass ratio r≲ O(1) is still experimentally allowed and can be explored in the future LFV experiments. Similarly, the contribution of a relatively light triplet to the LNV process of neutrinoless double beta decay could be significant, disfavouring a part of the model parameter space otherwise allowed by LFV constraints. Nevertheless, we find regions of parameter space consistent with both LFV and LNV searches, for which the values of the total effective neutrino mass can be accessible to the next generation ton-scale experiments. Such light triplets can also be directly searched for at the LHC, thus providing a complementary probe of this scenario. Finally, we also study the implications of the triplet contribution for the left-right symmetric model interpretation of the recent diboson anomaly at the LHC.
Relic Neutrino Absorption Spectroscopy
Eberle, b
2004-01-28
Resonant annihilation of extremely high-energy cosmic neutrinos on big-bang relic anti-neutrinos (and vice versa) into Z-bosons leads to sizable absorption dips in the neutrino flux to be observed at Earth. The high-energy edges of these dips are fixed, via the resonance energies, by the neutrino masses alone. Their depths are determined by the cosmic neutrino background density, by the cosmological parameters determining the expansion rate of the universe, and by the large redshift history of the cosmic neutrino sources. We investigate the possibility of determining the existence of the cosmic neutrino background within the next decade from a measurement of these absorption dips in the neutrino flux. As a by-product, we study the prospects to infer the absolute neutrino mass scale. We find that, with the presently planned neutrino detectors (ANITA, Auger, EUSO, OWL, RICE, and SalSA) operating in the relevant energy regime above 10{sup 21} eV, relic neutrino absorption spectroscopy becomes a realistic possibility. It requires, however, the existence of extremely powerful neutrino sources, which should be opaque to nucleons and high-energy photons to evade present constraints. Furthermore, the neutrino mass spectrum must be quasi-degenerate to optimize the dip, which implies m{sub {nu}} 0.1 eV for the lightest neutrino. With a second generation of neutrino detectors, these demanding requirements can be relaxed considerably.
Neutrino oscillations with MINOS and MINOS+
NASA Astrophysics Data System (ADS)
Whitehead, L. H.
2016-07-01
The MINOS experiment ran from 2003 until 2012 and collected a data sample including 10.71 ×1020 protons-on-target (POT) of beam neutrinos, 3.36 ×1020 POT of beam antineutrinos and an atmospheric neutrino exposure of 37.88 kt yrs. The final measurement of the atmospheric neutrino oscillation parameters, Δ m322 and θ23, came from a full three flavour oscillation analysis of the combined CC νμ and CC ν‾μ beam and atmospheric samples and the CC νe and CC ν‾e appearance samples. This analysis yielded the most precise measurement of the atmospheric mass splitting Δ m322 performed to date. The results are | Δ m322 | = [ 2.28- 2.46 ] ×10-3 eV2 (68%) and sin2 θ23 = 0.35- 0.65 (90%) in the normal hierarchy, and | Δ m322 | = [ 2.32- 2.53 ] ×10-3 eV2 (68%) and sin2 θ23 = 0.34- 0.67 (90%) in the inverted hierarchy. The successor to MINOS in the NOνA era at FNAL, MINOS+, is now collecting data mostly in the 3- 10 GeV region, and an analysis of νμ disappearance using the first 2.99 ×1020 POT of data produced results very consistent with those from MINOS. Future data will further test the standard neutrino oscillation paradigm and allow for improved searches for exotic phenomena including sterile neutrinos, large extra dimensions and non-standard interactions.
Muon and Tau Neutrinos Spectra from Solar Flares
NASA Astrophysics Data System (ADS)
Fargion, Daniele; Moscato, Federica
2003-12-01
Most power-full solar flare as the ones occurred on 23th February 1956, September 29th 1989, 28th October and on 2nd-4th November 2003 are sources of cosmic rays, X, gamma and neutrino bursts. These flares took place both on front or in the edge and in the hidden solar disk. The 4th November event was the most powerful X event in the highest known rank category X28 just at horizons. The observed and estimated total flare energy (EFL ≃ 1031div 1033 erg) should be a source of a prompt secondary neutrino burst originated, by proton-proton-pion production on the sun itself; a more delayed and spread neutrino flux signal arise by the solar charged flare particles reaching the terrestrial atmosphere. These first earliest prompt solar neutrino burst might be observed, in a few neutrino clustered events, in present or future largest neutrino underground detectors as Super-Kamiokande one, in time correlation with the X-Radio flare. The onset in time correlation has great statistical significance. Our first estimate on the neutrino number events detection at the Super-Kamiokande II Laboratory for horizontal or hidden flare is found to be few events: NeV_bar{ν}_e≃ 0.63&etae (
HALO the helium and lead observatory for supernova neutrinos
NASA Astrophysics Data System (ADS)
Duba, C. A.; Duncan, F.; Farine, J.; Habig, A.; Hime, A.; Robertson, R. G. H.; Scholberg, K.; Shantz, T.; Virtue, C. J.; Wilkerson, J. F.; Yen, S.
2008-11-01
The Helium and Lead Observatory (HALO) is a supernova neutrino detector under development for construction at SNOLAB. It is intended to fulfill a niche as a long term, low cost, high livetime, and low maintenance, dedicated supernova detector. It will be constructed from 80 tonnes of lead, from the decommissioning of the Deep River Cosmic Ray Station, and instrumented with approximately 384 meters of 3He neutron detectors from the final phase of the SNO experiment. Charged- and Neutral-Current neutrino interactions in lead expel neutrons from the lead nuclei making a burst of detected neutrons the signature for the detection of a supernova. Existing neutrino detectors are mostly of the water Cerenkov and liquid scintillator types, which are primarily sensitive to electron anti-neutrinos via charged-current interactions on the hydrogen nuclei in these materials. By contrast, the large neutron excess of a heavy nucleus like Pb acts to Pauli-block pranglen transitions induced by electron anti-neutrinos, making HALO primarily sensitive to electron neutrinos. While any supernova neutrino data would provide an invaluable window into supernova dynamics, the electron neutrino CC channel has interesting sensitivity to particle physics through flavour-swapping and spectral splitting due to MSW-like collective neutrino-neutrino interactions in the core of the supernova, the only place in the universe where there is a sufficient density of neutrinos for this to occur. Such data could provide a test for θ13 ≠ 0 and an inverted neutrino mass hierarchy. In addition, the ratio of 1-neutron to 2-neutron events would be a measure of the temperature of the cooling neutron star. For the 80 tonne detector, a supernova at 10 kpc is estimated to produce 43 detected neutrons in the absence of collective ν-ν interactions, and many more in their presence. The high neutrino cross-section and low neutron absorption cross-section of lead, along with the modest cost of lead, makes this
CP violation from flavor symmetry in a lepton quarticity dark matter model
NASA Astrophysics Data System (ADS)
Chuliá, Salvador Centelles; Srivastava, Rahul; Valle, José W. F.
2016-10-01
We propose a simple Δ (27) ⊗Z4 model where neutrinos are predicted to be Dirac fermions. The smallness of their masses follows from a type-I seesaw mechanism and the leptonic CP violating phase correlates with the pattern of Δ (27) flavor symmetry breaking. The scheme naturally harbors a WIMP dark matter candidate associated to the Dirac nature of neutrinos, in that the same Z4 lepton number symmetry also ensures dark matter stability.
Neutrino Oscillations with Three Active and Three Sterile Neutrinos
NASA Astrophysics Data System (ADS)
Kisslinger, Leonard S.
2016-07-01
This is an extension of estimates of the probability of μ to e neutrino oscillation with one sterile neutrino to three sterile neutrinos, using a 6x6 matrix. Since the mixing angle for only one sterile neutrino has been experimentally determined, we estimate the μ to e neutrino oscillation probability with different mixing angles for two of the sterile neutrinos.
Signals of inert doublet dark matter in neutrino telescopes
Agrawal, Prateek; Dolle, Ethan M.; Krenke, Christopher A.
2009-01-01
One of the simplest extensions of the standard model that explains the observed abundance of dark matter is the inert doublet model. In this theory a discrete symmetry ensures that the neutral component of an additional electroweak doublet scalar is stable and constitutes a dark matter candidate. As massive bodies such as the Sun and Earth move through the dark matter halo, dark matter particles can become gravitationally trapped in their cores. Annihilations of these particles result in neutrinos, which can potentially be observed with neutrino telescopes. We calculate the neutrino detection rate at these experiments from inert doublet dark matter annihilations in the cores of the Sun and the Earth.
NASA Astrophysics Data System (ADS)
Mu, Cheng-Fu; Sun, Gao-Feng; Zhuang, Peng-Fei
2009-03-01
Electric charge neutrality provides a relationship between chiral dynamics and neutrino propagation in compact stars. Due to the sudden drop of the electron density at thefirst-order chiral phase transition, the oscillation for low energy neutrinos is significant and can be regarded as a signature of chiral symmetry restoration in the core of compact stars.
A light Zeldovich-Konopinski-Mahmoud neutrino with a large magnetic moment
NASA Astrophysics Data System (ADS)
Ecker, G.; Grimus, W.; Neufeld, H.
1989-11-01
We propose a non-abelian extension of a Zeldovich-Konopinski-Mahmoud lepton number symmetry which gives rise to a naturally light Dirac neutrino with a magnetic moment of O(10 -11μB). The neutrino mass appears first at the two-loop level and is well below the experimental upper bound.
Novel Frameworks for Dark Matter and Neutrino Masses
NASA Astrophysics Data System (ADS)
Schmidt, Daniel
2013-12-01
The established light neutrino masses and the Dark Matter of the Universe both require physics beyond the Standard Model for their theoretical explanation. Models that provide a common framework for these two issues are very attractive. In particular, radiative mechanisms naturally yield light neutrino masses due to loop suppression factors. These corrections can comprise a link to the physics of Dark Matter. In most considerations, the Dark Matter relic density is produced by freeze-out. This thesis contributes to the elds of radiative neutrino masses and frozen-out Dark Matter. In detail, it is shown that in the Ma-model, right-handed neutrino Dark Matter can be directly detected by photon exchange at one-loop level. The Zee{Babu-model is extended such that it enjoys a global symmetry based on baryon and lepton number. This symmetry generates light neutrino masses and a mass for a stable Dark Matter particle by its spontaneous breaking. Moreover, this thesis provides a new production mechanism for keV sterile neutrino Dark Mattetr, which is based on the freeze-in scenario. In particular, keV sterile neutrino Dark Matter produced by the decay of a frozen-in scalar is investigated.
Consistency of WIMP Dark Matter as radiative neutrino mass messenger
NASA Astrophysics Data System (ADS)
Merle, Alexander; Platscher, Moritz; Rojas, Nicolás; Valle, José W. F.; Vicente, Avelino
2016-07-01
The scotogenic scenario provides an attractive approach to both Dark Matter and neutrino mass generation, in which the same symmetry that stabilises Dark Matter also ensures the radiative seesaw origin of neutrino mass. However the simplest scenario may suffer from inconsistencies arising from the spontaneous breaking of the underlying ℤ 2 symmetry. Here we show that the singlet-triplet extension of the simplest model naturally avoids this problem due to the presence of scalar triplets neutral under the ℤ 2 which affect the evolution of the couplings in the scalar sector. The scenario offers good prospects for direct WIMP Dark Matter detection through the nuclear recoil method.
Dark photons as fractional cosmic neutrino masquerader
Ng, Kin-Wang; Tu, Huitzu; Yuan, Tzu-Chiang E-mail: huitzu@phys.sinica.edu.tw
2014-09-01
Recently, Weinberg proposed a Higgs portal model with a spontaneously broken global U(1) symmetry in which Goldstone bosons may be masquerading as fractional cosmic neutrinos. We extend the model by gauging the U(1) symmetry. This gives rise to the so-called dark photon and dark Higgs. The dark photons can constitute about 0.912 (0.167) to the effective number of light neutrino species if they decouple from the thermal bath before the pions become non-relativistic and after (before) the QCD transition. Restriction on the parameter space of the portal coupling and the dark Higgs mass is obtained from the freeze-out condition of the dark photons. Combining with the collider data constraints on the invisible width of the standard model Higgs requires the dark Higgs mass to be less than a few GeV.
A minimal model of neutrino flavor
NASA Astrophysics Data System (ADS)
Luhn, Christoph; Parattu, Krishna Mohan; Wingerter, Akın
2012-12-01
Models of neutrino mass which attempt to describe the observed lepton mixing pattern are typically based on discrete family symmetries with a non-Abelian and one or more Abelian factors. The latter so-called shaping symmetries are imposed in order to yield a realistic phenomenology by forbidding unwanted operators. Here we propose a supersymmetric model of neutrino flavor which is based on the group T 7 and does not require extra {Z} N or U(1) factors in the Yukawa sector, which makes it the smallest realistic family symmetry that has been considered so far. At leading order, the model predicts tribimaximal mixing which arises completely accidentally from a combination of the T 7 Clebsch-Gordan coefficients and suitable flavon alignments. Next-to-leading order (NLO) operators break the simple tribimaximal structure and render the model compatible with the recent results of the Daya Bay and Reno collaborations which have measured a reactor angle of around 9°. Problematic NLO deviations of the other two mixing angles can be controlled in an ultraviolet completion of the model. The vacuum alignment mechanism that we use necessitates the introduction of a hidden flavon sector that transforms under a {Z} 6 symmetry, thereby spoiling the minimality of our model whose flavor symmetry is then T 7 × {Z} 6.
Experimental Neutrino Physics: Final Report
Lane, Charles E.; Maricic, Jelena
2012-09-05
Experimental studies of neutrino properties, with particular emphasis on neutrino oscillation, mass and mixing parameters. This research was pursued by means of underground detectors for reactor anti-neutrinos, measuring the flux and energy spectra of the neutrinos. More recent investigations have been aimed and developing detector technologies for a long-baseline neutrino experiment (LBNE) using a neutrino beam from Fermilab.
None
2016-07-12
- Physics, as we know it, attempts to interpret the diverse natural phenomena as particular manifestations of general laws. This vision of a world ruled by general testable laws is relatively recent in the history of mankind. Basically it was initiated by the Galilean inertial principle. The subsequent rapid development of large-scale physics is certainly tributary to the fact that gravitational and electromagnetic forces are long-range and hence can be perceived directly without the mediation of highly sophisticated technical devices. - The discovery of subatomic structures and of the concomitant weak and strong short-range forces raised the question of how to cope with short-range forces in relativistic quantum field theory. The Fermi theory of weak interactions, formulated in terms of point-like current-current interaction, was well-defined in lowest order perturbation theory and accounted for existing experimental data.However, it was inconsistent in higher orders because of uncontrollable divergent quantum fluctuations. In technical terms, in contradistinction to quantum electrodynamics, the Fermi theorywas not ârenormalizableâ. This difficulty could not be solved by smoothing the point-like interaction by a massive, and therefore short-range, charged âvectorâ particle exchange: theories with massive charged vector bosons were not renormalizable either. In the early nineteen sixties, there seemed to be insuperable obstacles to formulating a consistent theory with short-range forces mediated by massive vectors. - The breakthrough came from the notion of spontaneous symmetry breaking which arose in the study of phase transitions and was introduced in field theory by Nambu in 1960. - Ferromagnets illustrate the notion in phase transitions. Although no direction is dynamically preferred, the magnetization selects a global orientation. This is a spontaneous broken symmetry(SBS)of rotational invariance. Such continuous SBS imply the existence of
2011-02-24
- Physics, as we know it, attempts to interpret the diverse natural phenomena as particular manifestations of general laws. This vision of a world ruled by general testable laws is relatively recent in the history of mankind. Basically it was initiated by the Galilean inertial principle. The subsequent rapid development of large-scale physics is certainly tributary to the fact that gravitational and electromagnetic forces are long-range and hence can be perceived directly without the mediation of highly sophisticated technical devices. - The discovery of subatomic structures and of the concomitant weak and strong short-range forces raised the question of how to cope with short-range forces in relativistic quantum field theory. The Fermi theory of weak interactions, formulated in terms of point-like current-current interaction, was well-defined in lowest order perturbation theory and accounted for existing experimental data.However, it was inconsistent in higher orders because of uncontrollable divergent quantum fluctuations. In technical terms, in contradistinction to quantum electrodynamics, the Fermi theorywas not “renormalizable”. This difficulty could not be solved by smoothing the point-like interaction by a massive, and therefore short-range, charged “vector” particle exchange: theories with massive charged vector bosons were not renormalizable either. In the early nineteen sixties, there seemed to be insuperable obstacles to formulating a consistent theory with short-range forces mediated by massive vectors. - The breakthrough came from the notion of spontaneous symmetry breaking which arose in the study of phase transitions and was introduced in field theory by Nambu in 1960. - Ferromagnets illustrate the notion in phase transitions. Although no direction is dynamically preferred, the magnetization selects a global orientation. This is a spontaneous broken symmetry(SBS)of rotational invariance. Such continuous SBS imply the existence of
Saoulidou, Niki
2016-07-12
Neutrino oscillations provide the first evidenceÂ for physics beyond the Standard Model. I will briefly overview the neutrino "hi-story", describing key discoveries over the past decades that shaped our understanding of neutrinos and their behavior. Fermilab was, is and hopefully will be at the forefront of the accelerator neutrino experiments.Â NuMI, the most powerful accelerator neutrino beam in the world has ushered us into the era of precise measurements. Its further upgrades may give a chance to tackle the remaining mysteries of the neutrino mass hierarchy and possible CP violation.
Neutrino Nucleosynthesis in Supernovae
Yoshida, Takashi; Suzuki, Toshio; Chiba, Satoshi; Kajino, Toshitaka; Yokomakura, Hidekazu; Kimura, Keiichi; Takamura, Akira; Hartmann, Dieter H.
2009-05-04
Neutrino nucleosynthesis is an important synthesis process for light elements in supernovae. One important physics input of neutrino nucleosynthesis is cross sections of neutrino-nucleus reactions. The cross sections of neutrino-{sup 12}C and {sup 4}He reactions are derived using new shell model Hamiltonians. With the new cross sections, light element synthesis of a supernova is investigated. The appropriate range of the neutrino temperature for supernovae is constrained to be between 4.3 MeV and 6.5 MeV from the {sup 11}B abundance in Galactic chemical evolution. Effects by neutrino oscillations are also discussed.
Origin of constrained maximal CP violation in flavor symmetry
NASA Astrophysics Data System (ADS)
He, Hong-Jian; Rodejohann, Werner; Xu, Xun-Jie
2015-12-01
Current data from neutrino oscillation experiments are in good agreement with δ = -π/2 and θ23 =π/4 under the standard parametrization of the mixing matrix. We define the notion of "constrained maximal CP violation" (CMCPV) for predicting these features and study their origin in flavor symmetry. We derive the parametrization-independent solution of CMCPV and give a set of equivalent definitions for it. We further present a theorem on how the CMCPV can be realized. This theorem takes the advantage of residual symmetries in neutrino and charged lepton mass matrices, and states that, up to a few minor exceptions, (| δ | ,θ23) = (π/2 ,π/4) is generated when those symmetries are real. The often considered μ- τ reflection symmetry, as well as specific discrete subgroups of O(3), is a special case of our theorem.
Heavy flavour physics from top to bottom
Paulini, M.; CDF and D0 Collaborations
1997-01-01
We review the status of heavy flavour physics at the Fermilab Tevatron collider by summarizing recent top quark and B physics results from CDF and D0. In particular we discuss the measurement of the top quark mass and top production cross section as well as B meson lifetimes and time dependent B{bar B} mixing results. An outlook of perspectives for top and B physics in Run II starting in 1999 is also given. 38 refs., 23 figs., 8 tabs.
Heavy flavour physics from top to bottom
Paulini, M.; CDF and D0 Collaboration
1998-02-01
We review the status of heavy flavour physics at the Fermilab Tevatron collider by summarizing recent top quark and B physics results from CDF and D0. In particular we discuss the measurement of the top quark mass and top production cross section as well as B meson lifetimes and time dependent B{anti B} mixing results. An outlook of perspectives for top and B physics in Run II starting in 1999 is also given.
The Erosive Potential of Some Flavoured Waters
Rees, Jeremy; Loyn, Theresa; Hunter, Lindsay; Sadaghiani, Leili; Gilmour, Alan
2007-01-01
Objectives To assess the erosive potential of a number of readily available flavoured waters in the laboratory. Methods The erosive potential was assessed by measuring the pH, neutralisable acidity and ability to erode enamel. These were compared to an orange juice positive control. Results The pH of the flavoured waters ranged from 2.64–3.24 with their neutralisable acidity ranging from 4.16–16.30 mls of 0.1M NaOH. The amount of enamel removed following 1-hour immersion in the drinks ranged from 1.18–6.86 microns. In comparison, the orange juice control had a pH of 3.68, a neutralisable acidity of 19.68 mls of 0.1 M NaOH and removed 3.24 microns of enamel. Conclusions Many of the flavoured waters tested were found to be as erosive as orange juice. This information will be of use to clinicians when counselling patients with tooth surface loss. (Eur J Dent 2007;1:5–9) PMID:19212489
Neutrino Cloud Instabilities Just above the Neutrino Sphere of a Supernova.
Sawyer, R F
2016-02-26
Most treatments of neutrino flavor evolution, above a surface of the last scattering, take identical angular distributions on this surface for the different initial (unmixed) flavors, and for particles and antiparticles. Differences in these distributions must be present, as a result of the species-dependent scattering cross sections lower in the star. These lead to a new set of nonlinear equations, unstable even at the initial surface with respect to perturbations that break all-over spherical symmetry. There could be important consequences for explosion dynamics as well as for the neutrino pulse in the outer regions.
Scalar dark matter and its connection with neutrino physics
NASA Astrophysics Data System (ADS)
Peinado, E.
2015-11-01
The existence of non-baryonic Dark Matter is well established by cosmological and astrophysical probes, however its detailed nature still remains elusive. Among the extensions of the Standard Model (SM) explaining the DM relic abundance, the simplest one is the inert dark matter, where a scalar field is added to the Standard Model which is stabilized by a Z2 symmetry. We intend to give a brief review of this scenario and its possible connection with neutrino physics. In particular the discrete dark matter mechanism will be outlined. This mechanism consists in an extended SM with a non-Abelian flavor symmetry. When the flavor symmetry is spontaneously broken by the electroweak symmetry breaking mechanism, it explains the neutrino mixing patterns and at the same time renders the dark matter stable.
Messages on Flavour Physics Beyond the Standard Model
NASA Astrophysics Data System (ADS)
Buras, Andrzej J.
2008-12-01
We present a brief summary of the main results on flavour physics beyond the Standard Model that have been obtained in 2008 by my collaborators and myself in my group at TUM. In particular we list main messages coming from our analyses of flavour and CP-violating processes in Supersymmetry, Littlest Higgs model with T-Parity and a warped extra dimension model with custodial protection for the flavour diagonal and non-diagonal Z boson couplings.
DOE R&D Accomplishments Database
Davis, R. Jr.; Evans, J. C.; Cleveland, B. T.
1978-04-28
A summary of the results of the Brookhaven solar neutrino experiment is given and discussed in relation to solar model calculations. A review is given of the merits of various new solar neutrino detectors that were proposed.
Scholberg, K.
2015-07-15
In this presentation I summarize the main detection channels for neutrinos from core-collapse supernovae, and describe current status of and future prospects for supernova-neutrino-sensitive detectors worldwide.
Pair Production Constraints on Superluminal Neutrinos Revisited
Brodsky, Stanley J.; Gardner, Susan; /Kentucky U.
2012-02-16
We revisit the pair creation constraint on superluminal neutrinos considered by Cohen and Glashow in order to clarify which types of superluminal models are constrained. We show that a model in which the superluminal neutrino is effectively light-like can evade the Cohen-Glashow constraint. In summary, any model for which the CG pair production process operates is excluded because such timelike neutrinos would not be detected by OPERA or other experiments. However, a superluminal neutrino which is effectively lightlike with fixed p{sup 2} can evade the Cohen-Glashow constraint because of energy-momentum conservation. The coincidence involved in explaining the SN1987A constraint certainly makes such a picture improbable - but it is still intrinsically possible. The lightlike model is appealing in that it does not violate Lorentz symmetry in particle interactions, although one would expect Hughes-Drever tests to turn up a violation eventually. Other evasions of the CG constraints are also possible; perhaps, e.g., the neutrino takes a 'short cut' through extra dimensions or suffers anomalous acceleration in matter. Irrespective of the OPERA result, Lorentz-violating interactions remain possible, and ongoing experimental investigation of such possibilities should continue.
Constraints on the neutrino emission from the Galactic Ridge with the ANTARES telescope
NASA Astrophysics Data System (ADS)
Adrián-Martínez, S.; Albert, A.; André, M.; Anghinolfi, M.; Anton, G.; Ardid, M.; Aubert, J.-J.; Avgitas, T.; Baret, B.; Barrios-Martí, J.; Basa, S.; Bertin, V.; Biagi, S.; Bormuth, R.; Bouwhuis, M. C.; Bruijn, R.; Brunner, J.; Busto, J.; Capone, A.; Caramete, L.; Carr, J.; Celli, S.; Chiarusi, T.; Circella, M.; Coleiro, A.; Coniglione, R.; Costantini, H.; Coyle, P.; Creusot, A.; Deschamps, A.; De Bonis, G.; Distefano, C.; Donzaud, C.; Dornic, D.; Drouhin, D.; Eberl, T.; El Bojaddaini, I.; Elsässer, D.; Enzenhöfer, A.; Fehn, K.; Felis, I.; Fusco, L. A.; Galatà, S.; Gay, P.; Geißelsöder, S.; Geyer, K.; Giordano, V.; Gleixner, A.; Glotin, H.; Gracia-Ruiz, R.; Graf, K.; Hallmann, S.; van Haren, H.; Heijboer, A. J.; Hello, Y.; Hernández-Rey, J. J.; Hößl, J.; Hofestädt, J.; Hugon, C.; Illuminati, G.; James, C. W.; de Jong, M.; Kadler, M.; Kalekin, O.; Katz, U.; Kießling, D.; Kouchner, A.; Kreter, M.; Kreykenbohm, I.; Kulikovskiy, V.; Lachaud, C.; Lahmann, R.; Lefèvre, D.; Leonora, E.; Loucatos, S.; Marcelin, M.; Margiotta, A.; Marinelli, A.; Martínez-Mora, J. A.; Mathieu, A.; Michael, T.; Migliozzi, P.; Moussa, A.; Mueller, C.; Nezri, E.; Păvălaş, G. E.; Pellegrino, C.; Perrina, C.; Piattelli, P.; Popa, V.; Pradier, T.; Racca, C.; Riccobene, G.; Roensch, K.; Saldaña, M.; Samtleben, D. F. E.; Sánchez-Losa, A.; Sanguineti, M.; Sapienza, P.; Schnabel, J.; Schüssler, F.; Seitz, T.; Sieger, C.; Spurio, M.; Stolarczyk, Th.; Taiuti, M.; Trovato, A.; Tselengidou, M.; Turpin, D.; Tönnis, C.; Vallage, B.; Vallée, C.; Van Elewyck, V.; Visser, E.; Vivolo, D.; Wagner, S.; Wilms, J.; Zornoza, J. D.; Zúñiga, J.
2016-09-01
A highly significant excess of high-energy astrophysical neutrinos has been reported by the IceCube Collaboration. Some features of the energy and declination distributions of IceCube events hint at a North/South asymmetry of the neutrino flux. This could be due to the presence of the bulk of our Galaxy in the Southern hemisphere. The ANTARES neutrino telescope, located in the Mediterranean Sea, has been taking data since 2007. It offers the best sensitivity to muon neutrinos produced by galactic cosmic ray interactions in this region of the sky. In this letter a search for an extended neutrino flux from the Galactic Ridge region is presented. Different models of neutrino production by cosmic ray propagation are tested. No excess of events is observed and upper limits for different neutrino flux spectral indices Γ are set. For Γ = 2.4 the 90% confidence level flux upper limit at 100 TeV for one neutrino flavour corresponds to Φ01 f (100 TeV) = 2.0 ṡ10-17 GeV-1cm-2s-1sr-1. Under this assumption, at most two events of the IceCube cosmic candidates can originate from the Galactic Ridge. A simple power-law extrapolation of the Fermi-LAT flux to account for IceCube High Energy Starting Events is excluded at 90% confidence level.
Non-Diagonal Flavour Observables in B and Collider Physics
Hurth, Tobias
2003-11-11
Until now the focus within the direct search for supersymmetry has mainly been on flavour diagonal observables. Recently lepton flavour violating signals at future electron positron colliders have been studied. There is now an opportunity to analyze the relations between collider observables and low-energy observables in the hadronic sector. In a first work in this direction, we study flavour violation in the squark decays of the second and third generations taking into account results from B physics, in particular from the rare decay b {yields} s gamma. Correlations between various squark decay modes can be used to get more precise information on various flavour violating parameters.
Dye, S. T.; Alderman, M.; Batygov, M.; Learned, J. G.; Matsuno, S.; Mahoney, J. M.; Pakvasa, S.; Rosen, M.; Smith, S.; Varner, G.; McDonough, W. F.
2009-12-17
Observations of geo-neutrinos measure radiogenic heat production within the earth, providing information on the thermal history and dynamic processes of the mantle. Two detectors currently observe geo-neutrinos from underground locations. Other detection projects in various stages of development include a deep ocean observatory. This paper presents the current status of geo-neutrino observation and describes the scientific capabilities of the deep ocean observatory, with emphasis on geology and neutrino physics.
Kayser, Boris
2012-06-01
To complement the neutrino-physics lectures given at the 2011 International School on Astro Particle Physics devoted to Neutrino Physics and Astrophysics (ISAPP 2011; Varenna, Italy), at the 2011 European School of High Energy Physics (ESHEP 2011; Cheila Gradistei, Romania), and, in modified form, at other summer schools, we present here a written description of the physics of neutrino oscillation. This description is centered on a new way of deriving the oscillation probability. We also provide a brief guide to references relevant to topics other than neutrino oscillation that were covered in the lectures. Neutrinos and photons are by far the most abundant elementary particles in the universe. Thus, if we would like to comprehend the universe, we must understand the neutrinos. Of course, studying the neutrinos is challenging, since the only known forces through which these electrically-neutral leptons interact are the weak force and gravity. Consequently, interactions of neutrinos in a detector are very rare events, so that very large detectors and intense neutrino sources are needed to make experiments feasible. Nevertheless, we have confirmed that the weak interactions of neutrinos are correctly described by the Standard Model (SM) of elementary particle physics. Moreover, in the last 14 years, we have discovered that neutrinos have nonzero masses, and that leptons mix. These discoveries have been based on the observation that neutrinos can change from one 'flavor' to another - the phenomenon known as neutrino oscillation. We shall explain the physics of neutrino oscillation, deriving the probability of oscillation in a new way. We shall also provide a very brief guide to references that can be used to study some major neutrino-physics topics other than neutrino oscillation.
Higgs production from sterile neutrinos at future lepton colliders
NASA Astrophysics Data System (ADS)
Antusch, Stefan; Cazzato, Eros; Fischer, Oliver
2016-04-01
In scenarios with sterile (right-handed) neutrinos that are subject to an approximate "lepton-number-like" symmetry, the heavy neutrinos (i.e. the mass eigenstates) can have masses around the electroweak scale and couple to the Higgs boson with, in principle, unsuppressed Yukawa couplings while accounting for the smallness of the light neutrinos' masses. In these scenarios, the on-shell production of heavy neutrinos and their subsequent decays into a light neutrino and a Higgs boson constitutes a hitherto unstudied resonant contribution to the Higgs production mechanism. We investigate the relevance of this resonant mono-Higgs production mechanism in leptonic collisions, including thepresent experimental constraints on the neutrino Yukawa couplings, and we determine the sensitivity of future lepton colliders to the heavy neutrinos. With Monte Carlo event sampling and a simulation of the detector response we find that, at future lepton colliders, neutrino Yukawa couplings below the percent level can lead to observable deviations from the SM and, furthermore, the sensitivity improves with higher center-of-mass energies (for identical integrated luminosities).
Continuous symmetry measures for complex symmetry group.
Dryzun, Chaim
2014-04-01
Symmetry is a fundamental property of nature, used extensively in physics, chemistry, and biology. The Continuous symmetry measures (CSM) is a method for estimating the deviation of a given system from having a certain perfect symmetry, which enables us to formulate quantitative relation between symmetry and other physical properties. Analytical procedures for calculating the CSM of all simple cyclic point groups are available for several years. Here, we present a methodology for calculating the CSM of any complex point group, including the dihedral, tetrahedral, octahedral, and icosahedral symmetry groups. We present the method and analyze its performances and errors. We also introduce an analytical method for calculating the CSM of the linear symmetry groups. As an example, we apply these methods for examining the symmetry of water, the symmetry maps of AB4 complexes, and the symmetry of several Lennard-Jones clusters.
NASA Astrophysics Data System (ADS)
Goodman, Frank
2012-02-01
I am writing with regard to the OPERA collaboration's recent publicizing of experimental results suggesting that neutrinos have been observed travelling faster than light (see "Superluminal neutrinos split OPERA collaboration", November 2011 pp12-13 "The brave new-media world", ibid p19; and "Speedy neutrinos", December 2011 pp20-21).
Neutrinos in the early universe
NASA Astrophysics Data System (ADS)
Kirilova, D.; Frere, J.-M.
2012-12-01
The neutrinos from the Big Bang or the Cosmic Neutrino Background (CNB) carry precious information from the early epoch when our universe was only 1 s old. Although not yet directly detected, CNB may be revealed indirectly through cosmological observations due to neutrino important cosmological influence. We review the cosmological role of neutrinos and the cosmological constraints on neutrino characteristics. Namely, we discuss the impact of neutrinos in the early universe: the cosmic expansion, neutrino decoupling, the role of neutrinos in the primordial production of light elements, leptogenesis, etc. We briefly discuss the role of neutrino at later stages of the universe. Due to the considerable cosmological influence of neutrinos, cosmological bounds on neutrino properties from observational data exist. We review the cosmological constraints on the effective number of neutrino species, neutrino mass and mixing parameters, lepton number of the universe, presence of sterile neutrino, etc.
Dark matter and global symmetries
NASA Astrophysics Data System (ADS)
Mambrini, Yann; Profumo, Stefano; Queiroz, Farinaldo S.
2016-09-01
General considerations in general relativity and quantum mechanics are known to potentially rule out continuous global symmetries in the context of any consistent theory of quantum gravity. Assuming the validity of such considerations, we derive stringent bounds from gamma-ray, X-ray, cosmic-ray, neutrino, and CMB data on models that invoke global symmetries to stabilize the dark matter particle. We compute up-to-date, robust model-independent limits on the dark matter lifetime for a variety of Planck-scale suppressed dimension-five effective operators. We then specialize our analysis and apply our bounds to specific models including the Two-Higgs-Doublet, Left-Right, Singlet Fermionic, Zee-Babu, 3-3-1 and Radiative See-Saw models. Assuming that (i) global symmetries are broken at the Planck scale, that (ii) the non-renormalizable operators mediating dark matter decay have O (1) couplings, that (iii) the dark matter is a singlet field, and that (iv) the dark matter density distribution is well described by a NFW profile, we are able to rule out fermionic, vector, and scalar dark matter candidates across a broad mass range (keV-TeV), including the WIMP regime.
New and trivial C P symmetry for extended A4 flavor
NASA Astrophysics Data System (ADS)
Nishi, C. C.
2016-05-01
The combination of νμ-ντ exchange together with C P conjugation in the neutrino sector (known as CPμ τ symmetry or μ τ reflection) is known to predict the viable pattern θ23=4 5 ° , a maximal Dirac C P phase, and trivial Majorana phases. We implement such a C P symmetry as a new C P symmetry in theories with A4 flavor. The implementation in a complete renormalizable model leads to a new form for the neutrino mass matrix that leads to further predictions: a normal hierarchical spectrum with a lightest mass and mβ β (0 ν 2 β ) of only few meV, and either ν1 or ν2 has opposite C P parity. An approximate Lμ-Lτ symmetry arises naturally and controls the flavor structure of the model. The light neutrino masses are generated by the extended seesaw mechanism with six right-handed neutrinos (RHNs). The requirement of negligible one-loop corrections to light neutrino masses, the validity of the extended seesaw approximation, and not too long-lived beyond-the-Standard-Model states to comply with big bang nucleosynthesis essentially restricts the parameters of the model to a small region: three relatively light right-handed neutrinos at the GeV scale, heavier neutrinos at the electroweak scale, and Yukawa couplings smaller than the electron Yukawa. Such small Yukawa couplings render these RHNs unobservable in terrestrial experiments.
Neutrino Observations from the Sudbury Neutrino Observatory
DOE R&D Accomplishments Database
Q. R. Ahmad, R. C. Allen, T. C. Andersen, J. D. Anglin, G. Bühler, J. C. Barton, E. W. Beier, M. Bercovitch, J. Bigu, S. Biller, R. A. Black, I. Blevis, R. J. Boardman, J. Boger, E. Bonvin, M. G. Boulay, M. G. Bowler, T. J. Bowles, S. J. Brice, M. C. Browne, T. V. Bullard, T. H. Burritt, K. Cameron, J. Cameron, Y. D. Chan, M. Chen, H. H. Chen, X. Chen, M. C. Chon, B. T. Cleveland, E. T. H. Clifford, J. H. M. Cowan, D. F. Cowen, G. A. Cox, Y. Dai, X. Dai, F. Dalnoki-Veress, W. F. Davidson, P. J. Doe, G. Doucas, M. R. Dragowsky, C. A. Duba, F. A. Duncan, J. Dunmore, E. D. Earle, S. R. Elliott, H. C. Evans, G. T. Ewan, J. Farine, H. Fergani, A. P. Ferraris, R. J. Ford, M. M. Fowler, K. Frame, E. D. Frank, W. Frati, J. V. Germani, S. Gil, A. Goldschmidt, D. R. Grant, R. L. Hahn, A. L. Hallin, E. D. Hallman, A. Hamer, A. A. Hamian, R. U. Haq, C. K. Hargrove, P. J. Harvey, R. Hazama, R. Heaton, K. M. Heeger, W. J. Heintzelman, J. Heise, R. L. Helmer, J. D. Hepburn, H. Heron, J. Hewett, A. Hime, M. Howe, J. G. Hykawy, M. C. P. Isaac, P. Jagam, N. A. Jelley, C. Jillings, G. Jonkmans, J. Karn, P. T. Keener, K. Kirch, J. R. Klein, A. B. Knox, R. J. Komar, R. Kouzes, T. Kutter, C. C. M. Kyba, J. Law, I. T. Lawson, M. Lay, H. W. Lee, K. T. Lesko, J. R. Leslie, I. Levine, W. Locke, M. M. Lowry, S. Luoma, J. Lyon, S. Majerus, H. B. Mak, A. D. Marino, N. McCauley, A. B. McDonald, D. S. McDonald, K. McFarlane, G. McGregor, W. McLatchie, R. Meijer Drees, H. Mes, C. Mifflin, G. G. Miller, G. Milton, B. A. Moffat, M. Moorhead, C. W. Nally, M. S. Neubauer, F. M. Newcomer, H. S. Ng, A. J. Noble, E. B. Norman, V. M. Novikov, M. O'Neill, C. E. Okada, R. W. Ollerhead, M. Omori, J. L. Orrell, S. M. Oser, A. W. P. Poon, T. J. Radcliffe, A. Roberge, B. C. Robertson, R. G. H. Robertson, J. K. Rowley, V. L. Rusu, E. Saettler, K. K. Schaffer, A. Schuelke, M. H. Schwendener, H. Seifert, M. Shatkay, J. J. Simpson, D. Sinclair, P. Skensved, A. R. Smith, M. W. E. Smith, N. Starinsky, T. D. Steiger, R. G. Stokstad, R. S. Storey, B. Sur, R. Tafirout, N. Tagg, N. W. Tanner, R. K. Taplin, M. Thorman, P. Thornewell, P. T. Trent, Y. I. Tserkovnyak, R. Van Berg, R. G. Van de Water, C. J. Virtue, C. E. Waltham, J.-X. Wang, D. L. Wark, N. West, J. B. Wilhelmy, J. F. Wilkerson, J. Wilson, P. Wittich, J. M. Wouters, and M. Yeh
2001-09-24
The Sudbury Neutrino Observatory (SNO) is a water imaging Cherenkov detector. Its usage of 1000 metric tons of D{sub 2}O as target allows the SNO detector to make a solar-model independent test of the neutrino oscillation hypothesis by simultaneously measuring the solar {nu}{sub e} flux and the total flux of all active neutrino species. Solar neutrinos from the decay of {sup 8}B have been detected at SNO by the charged-current (CC) interaction on the deuteron and by the elastic scattering (ES) of electrons. While the CC reaction is sensitive exclusively to {nu}{sub e}, the ES reaction also has a small sensitivity to {nu}{sub {mu}} and {nu}{sub {tau}}. In this paper, recent solar neutrino results from the SNO experiment are presented. It is demonstrated that the solar flux from {sup 8}B decay as measured from the ES reaction rate under the no-oscillation assumption is consistent with the high precision ES measurement by the Super-Kamiokande experiment. The {nu}{sub e} flux deduced from the CC reaction rate in SNO differs from the Super-Kamiokande ES results by 3.3{sigma}. This is evidence for an active neutrino component, in additional to {nu}{sub e}, in the solar neutrino flux. These results also allow the first experimental determination of the total active {sup 8}B neutrino flux from the Sun, and is found to be in good agreement with solar model predictions.
Generalised CP and trimaximal TM1 lepton mixing in S4 family symmetry
NASA Astrophysics Data System (ADS)
Li, Cai-Chang; Ding, Gui-Jun
2014-04-01
We construct two flavor models based on S4 family symmetry and generalised CP symmetry. In both models, the S4 family symmetry is broken down to the Z2SU subgroup in the neutrino sector, as a consequence, the trimaximal TM1 lepton mixing is produced. Depending on the free parameters in the flavon potential, the Dirac CP is predicted to be either conserved or maximally broken, and the Majorana CP phases are trivial. The two models differ in the neutrino sector. The flavon fields are involved in the Dirac mass terms at leading order in the first model, and the neutrino mass matrix contains three real parameters such that the absolute neutrino masses are fixed. Nevertheless, the flavon fields enter into the Majorana mass terms at leading order in the second model. The leading order lepton mixing is of the tri-bimaximal form which is broken down to TM1 by the next to leading order contributions.
Viable axion from gauged flavor symmetries
Berenstein, David; Perkins, Erik
2010-11-15
We consider a string-inspired nonsupersymmetric extension of the standard model with gauged anomalous U(1) flavor symmetries. Consistency requires the Green-Schwarz (GS) mechanism to cancel mixed anomalies. The additional required scalars provide Stueckelberg masses for the Z{sup '} particles associated to the gauged flavor symmetry, so they decouple at low energies. Our models also include a complex scalar field {phi} to generate Froggatt-Nielsen mass terms for light particles, giving a partial solution to the fermion mass problem. A residual approximate (anomalous) global symmetry survives at low energies. The associated pseudo-Goldstone mode is the phase of the {phi} scalar field, and it becomes the dominant contribution to the physical axion. An effective field theory analysis that includes neutrino masses gives a prediction for the axion decay constant. We find a simple model where the axion decay constant is in the center of the allowed window.
Baryon Triality And Neutrino Masses From An Anomalous FlavorU(1)
Dreiner, Herbi K.; Luhn, Christoph; Murayama, Hitoshi; Thormeier,Marc
2007-08-15
We construct a concise U(1){sub X} Froggatt-Nielsen model in which baryon triality, a discrete gauge Z{sub 3}-symmetry, arises from U(1){sub X} breaking. The proton is thus stable, however, R-parity is violated. With the proper choice of U(1){sub X} charges we can obtain neutrino masses and mixings consistent with an explanation of the atmospheric and solar neutrino anomalies in terms of neutrino oscillations, with no right-handed neutrinos required. The only mass scale apart from M{sub grav} is m{sub soft}.
Kajino, Toshitaka
2011-05-06
Neutrinos play the critical roles in nucleosynthesis of light-to-heavy mass nuclei in core-collapse supernovae. We study the nucleosynthesis induced by neutrino interactions and find suitable average neutrino temperatures in order to explain the observed solar system abundances of several isotopes {sup 7}Li, {sup 11}B, {sup 138}La and {sup 180}Ta. These isotopes are predominantly synthesized by the supernova {nu}-process. We also study the neutrino oscillation effects on their abundances and propose a method to determine the unknown neutrino oscillation parameters, i.e. {theta}{sub 13} and mass hierarchy.
Mass determination of neutrinos
NASA Technical Reports Server (NTRS)
Chiu, Hong-Yee
1988-01-01
A time-energy correlation method has been developed to determine the signature of a nonzero neutrino mass in a small sample of neutrinos detected from a distant source. The method is applied to the Kamiokande II (Hirata et al., 1987) and IMB (Bionta et al., 1987) observations of neutrino bursts from SN 1987A. Using the Kamiokande II data, the neutrino rest mass is estimated at 2.8 + 2.0, - 1.4 eV and the initial neutrino pulse is found to be less than 0.3 sec full width, followed by an emission tail lasting at least 10 sec.
NASA Technical Reports Server (NTRS)
Kazanas, Demosthenes; White, Nicholas E. (Technical Monitor)
2000-01-01
The great penetrating power of neutrinos makes them ideal probe of astrophysical sites and conditions inaccessible to other forms of radiation. These are the centers of stars (collapsing or not) and the centers of Active Galactic Nuclei (AGN). It has been suggested that AGN presented a very promising source of high energy neutrinos, possibly detectable by underwater neutrino detectors. This paper reviews the evolution of ideas concerning the emission of neutrinos from AGN in view of the more recent developments in gamma-ray astronomy and their implications for the neutrino emission from these class of objects.
Frobenius group T13 and the canonical seesaw mechanism applied to neutrino mixing
NASA Astrophysics Data System (ADS)
Hartmann, Christine
2012-01-01
The compatibility of the Frobenius group T13 with the canonical seesaw mechanism of neutrino mixing is examined. The standard model is extended minimally by introducing a family symmetry and three right-handed neutrinos. To fit experiments and place constraints on the possibilities, tribimaximal mixing is used as a guideline. The application of both a family symmetry group and the canonical seesaw mechanism naturally generates small neutrino masses. The various possibilities from combining these two models are listed. Enough constraints are produced to narrow down the parameters of the neutrino mass matrix to two. This is therefore a predictive model, where the physical neutrino masses and the allowed regions for neutrinoless double beta decay are suggested.
Seesaw scale discrete dark matter and two-zero texture Majorana neutrino mass matrices
NASA Astrophysics Data System (ADS)
Lamprea, J. M.; Peinado, E.
2016-09-01
In this paper we present a scenario where the stability of dark matter and the phenomenology of neutrinos are related by the spontaneous breaking of a non-Abelian flavor symmetry (A4). In this scenario the breaking is done at the seesaw scale, in such a way that what remains of the flavor symmetry is a Z2 symmetry, which stabilizes the dark matter. We have proposed two models based on this idea, for which we have calculated their neutrino mass matrices achieving two-zero texture in both cases. Accordingly, we have updated this two-zero texture phenomenology finding an interesting correlation between the reactor mixing angle and the sum of the light neutrino masses. We also have a correlation between the lightest neutrino mass and the neutrinoless double beta decay effective mass, obtaining a lower bound for the effective mass within the region of the nearly future experimental sensitivities.
Neutrino mass matrices with one texture zero and a vanishing neutrino mass
NASA Astrophysics Data System (ADS)
Gautam, Radha Raman; Singh, Madan; Gupta, Manmohan
2015-07-01
Assuming the Majorana nature of neutrinos, we investigate the singular one texture zero neutrino mass matrices in the flavor basis. We find that for the normal mass ordering with m1=0 , all six one texture zero classes are now ruled out at 3 σ confidence level, whereas for inverted mass ordering with m3=0 only four classes out of the six total can accommodate the latest neutrino oscillation data at 3 σ confidence level. Moreover, only two classes can accommodate the present data at 1 σ confidence level. We examine the phenomenological implications of the allowed classes for the effective Majorana mass and Dirac and Majorana C P -violating phases. Working within the framework of the type-I seesaw mechanism, we present simple discrete Abelian symmetry models leading to all the phenomenologically allowed classes.
Flavouring compounds in Indian potato snacks.
Raigond, Pinky; Singh, Brajesh; Dhulia, Akshita; Chopra, Shelly; Dutt, Som
2015-12-01
Market for processed potato products is rising day by day. Flavour plays important role in decision making by consumers due to their preferences for better tasting food. In potato and potato products, glutamic acid, aspartic acid, guanosine 5'-monophosphate (GMP) and adenosine 5'-monophosphate (AMP) are the major umami compounds which contribute towards flavour. Therefore, umami 5' nucleotides (AMP+GMP) were estimated from local potato products available as common fried products in the Indian markets and processed potato products being sold by the retailers. The analysis was also carried in raw, microwaved and pressure cooked tubers of forty seven Indian potato cultivars. Umami 5' nucleotide content ranged from 2.63 (Aloo seekh) to 8.26 μg/g FW (fried lachcha) in local potato products. In processed potato products, the content ranged from 2.72 μg/g FW (Smiles) to 14.75 μg/g FW (Aloo Bhujia). Along with aloo bhujia, umami 5' nucleotides were also high in dehydrated aloo lachcha (11.14 μg/g FW) and dehydrated potato chips (10.13 μg/g FW) and low in Smiles (2.72 μg/g FW) and Potato Shortz (3.40 μg/g FW). The study suggests that the potato products prepared solely from potato contained higher levels of umami 5' nucleotides compared to other products prepared by mixing potato with other cereals and vegetables. In Indian potato cultivars overall there was 14 % increase on microwave cooking and 31 % increase in flavouring compounds on pressure cooking. This type of study enabled in identifying better tasting cultivars for further product development and also to develop products with less addition of salt. PMID:26604408
Flavour perception of oxidation in beef.
Campo, M M; Nute, G R; Hughes, S I; Enser, M; Wood, J D; Richardson, R I
2006-02-01
Lipid oxidation is a major factor in meat quality. In order to relate human perceptions of lipid oxidation, as determined by a trained taste panel, to a chemical measurement of oxidation, we studied meat from animals with a wide range of potential oxidation through differences in their PUFA composition and by displaying the meat in high oxygen modified atmosphere packs for varying lengths of time. Meat was obtained from 73 Angus- and Charolais-cross steers from different trials that had been raised on 10 different diets: grass silage (high in C18:3, n-3), cereal concentrate (high in C18:2, n-6), three diets with 3% added fat consisting of three levels of protected lipid supplement (high in C18:2, n-6 and C18:3, n-3, ratio 1:1), a control with Megalac(®) (relatively saturated), three diets with three levels of inclusion of protected fish oil (high in C20:5 n-3 and C22:6 n-3) plus a constant amount of unprotected fish oil and a final diet with an unprotected fish oil control. The longissimus dorsi muscle was excised from the left carcass side, aged vacuum packaged for 10-13 days depending on the projects and frozen for less than eight months. TBARS and sensory analyses were performed on steaks displayed for 0, 4 or 9 days under simulated retail conditions, exposed to light in modified atmosphere packaging (CO(2):O(2); 25:75). Meat oxidation increased throughout display for each of the diets, as shown by a rise in TBARS values. This increase was not linear, differences between 0 and 4 days of display were smaller than between 4 and 9 days of display. The lowest TBARS and lowest increment occurred in the two control diets and the grass-fed animals, probably due to the more saturated fat of meat from animals fed the control diets and the higher content of vitamin E. Sensory attributes were also influenced by time of display. Positive attributes, such as beef flavour or overall liking, decreased throughout display, whereas negative attributes, such as abnormal and
Neutrino Factory Targets and the MICE Beam
Walaron, Kenneth Andrew
2007-01-01
The future of particle physics in the next 30 years must include detailed study of neutrinos. The first proof of physics beyond the Standard Model of particle physics is evident in results from recent neutrino experiments which imply that neutrinos have mass and flavour mixing. The Neutrino Factory is the leading contender to measure precisely the neutrino mixing parameters to probe beyond the Standard Model physics. Significantly, one must look to measure the mixing angle θ_{13} and investigate the possibility of leptonic CP violation. If found this may provide a key insight into the origins of the matter/anti- matter asymmetry seen in the universe, through the mechanism of leptogenesis. The Neutrino Factory will be a large international multi-billion dollar experiment combining novel new accelerator and long-baseline detector technology. Arguably the most important and costly features of this facility are the proton driver and cooling channel. This thesis will present simulation work focused on determining the optimal proton driver energy to maximise pion production and also simulation of the transport of this pion °ux through some candidate transport lattices. Bench-marking of pion cross- sections calculated by MARS and GEANT4 codes to measured data from the HARP experiment is also presented. The cooling channel aims to reduce the phase-space volume of the decayed muon beam to a level that can be e±ciently injected into the accelerator system. The Muon Ionisation Cooling Experiment (MICE) hosted by the Rutherford Appleton laboratory, UK is a proof-of-principle experiment aimed at measuring ionisation cooling. The experiment will run parasitically to the ISIS accelerator and will produce muons from pion decay. The MICE beamline provides muon beams of variable emittance and momentum to the MICE experiment to enable measurement of cooling over a wide range of beam conditions. Simulation work in the design of this beamline is presented in this thesis as
Quark flavour observables in the Littlest Higgs model with T-parity after LHC Run 1
NASA Astrophysics Data System (ADS)
Blanke, Monika; Buras, Andrzej J.; Recksiegel, Stefan
2016-04-01
The Littlest Higgs model with T-parity (LHT) belongs to the simplest new physics scenarios with new sources of flavour and CP violation. The latter originate in the interactions of ordinary quarks and leptons with heavy mirror quarks and leptons that are mediated by new heavy gauge bosons. Also a heavy fermionic top partner is present in this model which communicates with the SM fermions by means of standard W^± and Z^0 gauge bosons. We present a new analysis of quark flavour observables in the LHT model in view of the oncoming flavour precision era. We use all available information on the CKM parameters, lattice QCD input and experimental data on quark flavour observables and corresponding theoretical calculations, taking into account new lower bounds on the symmetry breaking scale and the mirror quark masses from the LHC. We investigate by how much the branching ratios for a number of rare K and B decays are still allowed to depart from their SM values. This includes K^+→ π ^+ν bar{ν }, KL→ π ^0ν bar{ν }, K_L→ μ ^+μ ^-, B→ X_sγ , B_{s,d}→ μ ^+μ ^-, B→ K^{(*)}ℓ ^+ℓ ^-, B→ K^{(*)}ν bar{ν }, and \\varepsilon '/\\varepsilon . Taking into account the constraints from Δ F=2 processes, significant departures from the SM predictions for K^+→ π ^+ν bar{ν } and KL→ π ^0ν bar{ν } are possible, while the effects in B decays are much smaller. In particular, the LHT model favours B(Bs→ μ ^+μ ^-) ≥ B(Bs→ μ ^+μ ^-)_SM, which is not supported by the data, and the present anomalies in B→ K^{(*)}ℓ ^+ℓ ^- decays cannot be explained in this model. With the recent lattice and large N input the imposition of the \\varepsilon '/\\varepsilon constraint implies a significant suppression of the branching ratio for KL→ π ^0ν bar{ν } with respect to its SM value while allowing only for small modifications of K^+→ π ^+ν bar{ν }. Finally, we investigate how the LHT physics could be distinguished from other models by means of
Observable T{sub 7} Lepton Flavor Symmetry at the Large Hadron Collider
Cao Qinghong; Khalil, Shaaban; Ma, Ernest; Okada, Hiroshi
2011-04-01
More often than not, models of flavor symmetry rely on the use of nonrenormalizable operators (in the guise of flavons) to accomplish the phenomenologically successful tribimaximal mixing of neutrinos. We show instead how a simple renormalizable two-parameter neutrino mass model of tribimaximal mixing can be constructed with the non-Abelian discrete symmetry T{sub 7} and the gauging of B-L. This is also achieved without the addition of auxiliary symmetries and particles present in almost all other proposals. Most importantly, it is verifiable at the Large Hadron Collider.
Observable T7 lepton flavor symmetry at the Large Hadron Collider.
Cao, Qing-Hong; Khalil, Shaaban; Ma, Ernest; Okada, Hiroshi
2011-04-01
More often than not, models of flavor symmetry rely on the use of nonrenormalizable operators (in the guise of flavons) to accomplish the phenomenologically successful tribimaximal mixing of neutrinos. We show instead how a simple renormalizable two-parameter neutrino mass model of tribimaximal mixing can be constructed with the non-Abelian discrete symmetry T(7) and the gauging of B-L. This is also achieved without the addition of auxiliary symmetries and particles present in almost all other proposals. Most importantly, it is verifiable at the Large Hadron Collider.
Peccei-Quinn symmetry for Dirac seesaw and leptogenesis
NASA Astrophysics Data System (ADS)
Gu, Pei-Hong
2016-07-01
We extend the DFSZ invisible axion model to simultaneously explain small Dirac neutrino masses and cosmic matter-antimatter asymmetry. After the Peccei-Quinn and electroweak symmetry breaking, the effective Yukawa couplings of the Dirac neutrinos to the standard model Higgs scalar can be highly suppressed by the ratio of the vacuum expectation value of an iso-triplet Higgs scalar over the masses of some heavy gauge-singlet fermions, iso-doublet Higgs scalars or iso-triplet fermions. The iso-triplet fields can carry a zero or nonzero hypercharge. Through the decays of the heavy gauge-singlet fermions, iso-doublet scalars or iso-triplet fermions, we can obtain a lepton asymmetry in the left-handed leptons and an opposite lepton asymmetry in the right-handed neutrinos. Since the right-handed neutrinos do not participate in the sphaleron processes, the left-handed lepton asymmetry can be partially converted to a baryon asymmetry.
Bilinear R-parity violation with flavor symmetry
NASA Astrophysics Data System (ADS)
Bazzocchi, F.; Morisi, S.; Peinado, E.; Valle, J. W. F.; Vicente, A.
2013-01-01
Bilinear R-parity violation (BRPV) provides the simplest intrinsically super-symmetric neutrino mass generation scheme. While neutrino mixing parameters can be probed in high energy accelerators, they are unfortunately not predicted by the theory. Here we propose a model based on the discrete flavor symmetry A 4 with a single R-parity violating parameter, leading to (i) correct Cabbibo mixing given by the Gatto-Sartori-Tonin formula, and a successful unification-like b-tau mass relation, and (ii) a correlation between the lepton mixing angles θ 13 and θ 23 in agreement with recent neutrino oscillation data, as well as a (nearly) massless neutrino, leading to absence of neutrinoless double beta decay.
Atmospheric Neutrinos: Background and Signal
Mocioiu, Irina
2010-11-24
We discuss a brief history of atmospheric neutrinos, from background to proton decay searches to proving neutrino oscillations. We then discuss how high statistics atmospheric neutrino measurements in the IceCube Deep Core Array can provide useful information about neutrino oscillation parameters and other neutrino properties.
Collective neutrino oscillations in supernovae
Duan, Huaiyu
2014-06-24
In a dense neutrino medium neutrinos can experience collective flavor transformation through the neutrino-neutrino forward scattering. In this talk we present some basic features of collective neutrino flavor transformation in the context in core-collapse supernovae. We also give some qualitative arguments for why and when this interesting phenomenon may occur and how it may affect supernova nucleosynthesis.
NASA Astrophysics Data System (ADS)
An, Fengpeng; An, Guangpeng; An, Qi; Antonelli, Vito; Baussan, Eric; Beacom, John; Bezrukov, Leonid; Blyth, Simon; Brugnera, Riccardo; Buizza Avanzini, Margherita; Busto, Jose; Cabrera, Anatael; Cai, Hao; Cai, Xiao; Cammi, Antonio; Cao, Guofu; Cao, Jun; Chang, Yun; Chen, Shaomin; Chen, Shenjian; Chen, Yixue; Chiesa, Davide; Clemenza, Massimiliano; Clerbaux, Barbara; Conrad, Janet; D'Angelo, Davide; De Kerret, Hervé; Deng, Zhi; Deng, Ziyan; Ding, Yayun; Djurcic, Zelimir; Dornic, Damien; Dracos, Marcos; Drapier, Olivier; Dusini, Stefano; Dye, Stephen; Enqvist, Timo; Fan, Donghua; Fang, Jian; Favart, Laurent; Ford, Richard; Göger-Neff, Marianne; Gan, Haonan; Garfagnini, Alberto; Giammarchi, Marco; Gonchar, Maxim; Gong, Guanghua; Gong, Hui; Gonin, Michel; Grassi, Marco; Grewing, Christian; Guan, Mengyun; Guarino, Vic; Guo, Gang; Guo, Wanlei; Guo, Xin-Heng; Hagner, Caren; Han, Ran; He, Miao; Heng, Yuekun; Hsiung, Yee; Hu, Jun; Hu, Shouyang; Hu, Tao; Huang, Hanxiong; Huang, Xingtao; Huo, Lei; Ioannisian, Ara; Jeitler, Manfred; Ji, Xiangdong; Jiang, Xiaoshan; Jollet, Cécile; Kang, Li; Karagounis, Michael; Kazarian, Narine; Krumshteyn, Zinovy; Kruth, Andre; Kuusiniemi, Pasi; Lachenmaier, Tobias; Leitner, Rupert; Li, Chao; Li, Jiaxing; Li, Weidong; Li, Weiguo; Li, Xiaomei; Li, Xiaonan; Li, Yi; Li, Yufeng; Li, Zhi-Bing; Liang, Hao; Lin, Guey-Lin; Lin, Tao; Lin, Yen-Hsun; Ling, Jiajie; Lippi, Ivano; Liu, Dawei; Liu, Hongbang; Liu, Hu; Liu, Jianglai; Liu, Jianli; Liu, Jinchang; Liu, Qian; Liu, Shubin; Liu, Shulin; Lombardi, Paolo; Long, Yongbing; Lu, Haoqi; Lu, Jiashu; Lu, Jingbin; Lu, Junguang; Lubsandorzhiev, Bayarto; Ludhova, Livia; Luo, Shu; Lyashuk, Vladimir; Möllenberg, Randolph; Ma, Xubo; Mantovani, Fabio; Mao, Yajun; Mari, Stefano M.; McDonough, William F.; Meng, Guang; Meregaglia, Anselmo; Meroni, Emanuela; Mezzetto, Mauro; Miramonti, Lino; Mueller, Thomas; Naumov, Dmitry; Oberauer, Lothar; Ochoa-Ricoux, Juan Pedro; Olshevskiy, Alexander; Ortica, Fausto; Paoloni, Alessandro; Peng, Haiping; Peng, Jen-Chieh; Previtali, Ezio; Qi, Ming; Qian, Sen; Qian, Xin; Qian, Yongzhong; Qin, Zhonghua; Raffelt, Georg; Ranucci, Gioacchino; Ricci, Barbara; Robens, Markus; Romani, Aldo; Ruan, Xiangdong; Ruan, Xichao; Salamanna, Giuseppe; Shaevitz, Mike; Sinev, Valery; Sirignano, Chiara; Sisti, Monica; Smirnov, Oleg; Soiron, Michael; Stahl, Achim; Stanco, Luca; Steinmann, Jochen; Sun, Xilei; Sun, Yongjie; Taichenachev, Dmitriy; Tang, Jian; Tkachev, Igor; Trzaska, Wladyslaw; van Waasen, Stefan; Volpe, Cristina; Vorobel, Vit; Votano, Lucia; Wang, Chung-Hsiang; Wang, Guoli; Wang, Hao; Wang, Meng; Wang, Ruiguang; Wang, Siguang; Wang, Wei; Wang, Yi; Wang, Yi; Wang, Yifang; Wang, Zhe; Wang, Zheng; Wang, Zhigang; Wang, Zhimin; Wei, Wei; Wen, Liangjian; Wiebusch, Christopher; Wonsak, Björn; Wu, Qun; Wulz, Claudia-Elisabeth; Wurm, Michael; Xi, Yufei; Xia, Dongmei; Xie, Yuguang; Xing, Zhi-zhong; Xu, Jilei; Yan, Baojun; Yang, Changgen; Yang, Chaowen; Yang, Guang; Yang, Lei; Yang, Yifan; Yao, Yu; Yegin, Ugur; Yermia, Frédéric; You, Zhengyun; Yu, Boxiang; Yu, Chunxu; Yu, Zeyuan; Zavatarelli, Sandra; Zhan, Liang; Zhang, Chao; Zhang, Hong-Hao; Zhang, Jiawen; Zhang, Jingbo; Zhang, Qingmin; Zhang, Yu-Mei; Zhang, Zhenyu; Zhao, Zhenghua; Zheng, Yangheng; Zhong, Weili; Zhou, Guorong; Zhou, Jing; Zhou, Li; Zhou, Rong; Zhou, Shun; Zhou, Wenxiong; Zhou, Xiang; Zhou, Yeling; Zhou, Yufeng; Zou, Jiaheng
2016-03-01
The Jiangmen Underground Neutrino Observatory (JUNO), a 20 kton multi-purpose underground liquid scintillator detector, was proposed with the determination of the neutrino mass hierarchy (MH) as a primary physics goal. The excellent energy resolution and the large fiducial volume anticipated for the JUNO detector offer exciting opportunities for addressing many important topics in neutrino and astro-particle physics. In this document, we present the physics motivations and the anticipated performance of the JUNO detector for various proposed measurements. Following an introduction summarizing the current status and open issues in neutrino physics, we discuss how the detection of antineutrinos generated by a cluster of nuclear power plants allows the determination of the neutrino MH at a 3-4σ significance with six years of running of JUNO. The measurement of antineutrino spectrum with excellent energy resolution will also lead to the precise determination of the neutrino oscillation parameters {{sin}}2{θ }12, {{Δ }}{m}212, and | {{Δ }}{m}{ee}2| to an accuracy of better than 1%, which will play a crucial role in the future unitarity test of the MNSP matrix. The JUNO detector is capable of observing not only antineutrinos from the power plants, but also neutrinos/antineutrinos from terrestrial and extra-terrestrial sources, including supernova burst neutrinos, diffuse supernova neutrino background, geoneutrinos, atmospheric neutrinos, and solar neutrinos. As a result of JUNO's large size, excellent energy resolution, and vertex reconstruction capability, interesting new data on these topics can be collected. For example, a neutrino burst from a typical core-collapse supernova at a distance of 10 kpc would lead to ˜5000 inverse-beta-decay events and ˜2000 all-flavor neutrino-proton ES events in JUNO, which are of crucial importance for understanding the mechanism of supernova explosion and for exploring novel phenomena such as collective neutrino oscillations
Formation of flavour compounds in the Maillard reaction.
van Boekel, M A J S
2006-01-01
This paper discusses the importance of the Maillard reaction for food quality and focuses on flavour compound formation. The most important classes of Maillard flavour compounds are indicated and it is shown where they are formed in the Maillard reaction. Some emphasis is given on the kinetics of formation of flavour compounds. It is concluded that the essential elements for predicting the formation of flavour compounds in the Maillard reaction are now established but much more work needs to be done on specific effects such as the amino acid type, the pH, water content and interactions in the food matrix. It is also concluded that most work is done on free amino acids but hardly anything on peptides and proteins, which could generate peptide- or protein-specific flavour compounds. PMID:16386869
Update of the flavour-physics constraints in the NMSSM
NASA Astrophysics Data System (ADS)
Domingo, Florian
2016-08-01
We consider the impact of several flavour-changing observables in the B- and the Kaon sectors on the parameter space of the NMSSM, in a minimal flavour violating version of this model. Our purpose consists in updating our previous results in [4] and designing an up-to-date flavour test for the public package NMSSMTools. We provide details concerning our implementation of the constraints in a series of brief reviews of the current status of the considered channels. Finally, we present a few consequences of these flavour constraints for the NMSSM, turning to two specific scenarios: one is characteristic of the MSSM-limit and illustrates the workings of charged-Higgs and genuinely supersymmetric contributions to flavour-changing processes; the second focus is a region where a light CP-odd Higgs is present. Strong limits are found whenever an enhancement factor - large tan β , light H^{± }, resonant pseudoscalar - comes into play.
Factors influencing the flavour of game meat: A review.
Neethling, J; Hoffman, L C; Muller, M
2016-03-01
Flavour is a very important attribute contributing to the sensory quality of meat and meat products. Although the sensory quality of meat includes orthonasal and retronasal aroma, taste, as well as appearance, juiciness and other textural attributes, the focus of this review is primarily on flavour. The influence of species, age, gender, muscle anatomical location, diet, harvesting conditions, ageing of meat, packaging and storage, as well as cooking method on the flavour of game meat are discussed. Very little research is available on the factors influencing the flavour of the meat derived from wild and free-living game species. The aim of this literature review is thus to discuss the key ante- and post-mortem factors that influence the flavour of game meat, with specific focus on wild and free-living South African game species.
Koskinen, David Jason
2009-02-01
The Main Injector Neutrino Oscillation Search (MINOS) is a long-baseline accelerator neutrino experiment designed to measure properties of neutrino oscillation. Using a high intensity muon neutrino beam, produced by the Neutrinos at Main Injector (NuMI) complex at Fermilab, MINOS makes two measurements of neutrino interactions. The first measurement is made using the Near Detector situated at Fermilab and the second is made using the Far Detector located in the Soudan Underground laboratory in northern Minnesota. The primary goal of MINOS is to verify, and measure the properties of, neutrino oscillation between the two detectors using the v _{μ}→ V_{τ} transition. A complementary measurement can be made to search for the existence of sterile neutrinos; an oft theorized, but experimentally unvalidated particle. The following thesis will show the results of a sterile neutrino search using MINOS RunI and RunII data totaling ~2.5 x 10^{20} protons on target. Due to the theoretical nature of sterile neutrinos, complete formalism that covers transition probabilities for the three known active states with the addition of a sterile state is also presented.
Beier, E.W.
1992-03-01
This document is a technical progress report on work performed at the University of Pennsylvania during the current year on the Sudbury Neutrino Observatory project. The motivation for the experiment is the measurement of neutrinos emitted by the sun. The Sudbury Neutrino Observatory (SNO) is a second generation dedicated solar neutrino experiment which will extend the results of our work with the Kamiokande II detector by measuring three reactions of neutrinos rather than the single reaction measured by the Kamiokande experiment. The collaborative project includes physicists from Canada, the United Kingdom, and the United States. Full funding for the construction of this facility was obtained in January 1990, and its construction is estimated to take five years. The motivation for the SNO experiment is to study the fundamental properties of neutrinos, in particular the mass and mixing parameters, which remain undetermined after decades of experiments in neutrino physics utilizing accelerators and reactors as sources of neutrinos. To continue the study of neutrino properties it is necessary to use the sun as a neutrino source. The long distance to the sun makes the search for neutrino mass sensitive to much smaller mass than can be studied with terrestrial sources. Furthermore, the matter density in the sun is sufficiently large to enhance the effects of small mixing between electron neutrinos and mu or tau neutrinos. This experiment, when combined with the results of the radiochemical {sup 37}Cl and {sup 71}Ga experiments and the Kamiokande II experiment, should extend our knowledge of these fundamental particles, and as a byproduct, improve our understanding of energy generation in the sun.
The simplest models of radiative neutrino mass
NASA Astrophysics Data System (ADS)
Law, Sandy S. C.; McDonald, Kristian L.
2014-04-01
The complexity of radiative neutrino-mass models can be judged by: (i) whether they require the imposition of ad hoc symmetries, (ii) the number of new multiplets they introduce and (iii) the number of arbitrary parameters that appear. Considering models that do not employ new symmetries, the simplest models have two new multiplets and a minimal number of new parameters. With this in mind, we search for the simplest models of radiative neutrino mass. We are led to two models, containing a real scalar triplet and a charged scalar doublet (respectively), in addition to the charged singlet scalar considered by Zee [h+ (1, 1, 2)]. These models are essentially simplified versions of the Zee model and appear to be the simplest models of radiative neutrino mass. However, despite successfully generating nonzero masses, present-day data is sufficient to rule these simple models out. The Zee and Zee-Babu models therefore remain as the simplest viable models. Moving beyond the minimal cases, we find a new model of two-loop masses that employs the charged doublet Φ (1, 2, 3) and the doubly-charged scalar k++ (1, 1, 4). This is the sole remaining model that employs only three new noncolored multiplets.
Reactor mixing angle from hybrid neutrino masses
NASA Astrophysics Data System (ADS)
Sierra, D. Aristizabal; de Medeiros Varzielas, I.
2014-07-01
In terms of its eigenvector decomposition, the neutrino mass matrix (in the basis where the charged lepton mass matrix is diagonal) can be understood as originating from a tribimaximal dominant structure with small deviations, as demanded by data. If neutrino masses originate from at least two different mechanisms, referred to as "hybrid neutrino masses", the experimentally observed structure naturally emerges provided one mechanism accounts for the dominant tribimaximal structure while the other is responsible for the deviations. We demonstrate the feasibility of this picture in a fairly model-independent way by using lepton-number-violating effective operators, whose structure we assume becomes dictated by an underlying A 4 flavor symmetry. We show that if a second mechanism is at work, the requirement of generating a reactor angle within its experimental range always fixes the solar and atmospheric angles in agreement with data, in contrast to the case where the deviations are induced by next-to-leading order effective operators. We prove this idea is viable by constructing an A 4-based ultraviolet completion, where the dominant tribimaximal structure arises from the type-I seesaw while the subleading contribution is determined by either type-II or type-III seesaw driven by a non-trivial A 4 singlet (minimal hybrid model). After finding general criteria, we identify all the N symmetries capable of producing such A 4-based minimal hybrid models.
Particle production with left-right neutrino oscillations
NASA Astrophysics Data System (ADS)
Enomoto, Seishi; Matsuda, Tomohiro
2016-03-01
When the Higgs field starts oscillation after Higgs inflation, gauge bosons are produced nonperturbatively near the enhanced symmetry point (ESP). Just after the particle production, when the Higgs field is going away from the ESP, these gauge bosons gain mass and decay or annihilate into Standard Model (SM) fermions. Left-handed neutrinos can be generated in that way. If one assumes the seesaw mechanism, the mass matrix of a pair of left- and right-handed neutrinos is nondiagonal. Although their mixing in the mass eigenstates is negligible in the true vacuum, it could be significant near the edge of the Higgs oscillation, where the off-diagonal component is large. Therefore, the left-handed neutrinos generated from the gauge bosons can start neutrino oscillation between the right-handed neutrinos. We study the particle production when such left-right (L-R) neutrino oscillation is significant. For a working example, the nonthermal leptogenesis scenario after Higgs inflation is examined, which cannot be realized without the L-R neutrino oscillation. The same mechanism could be applied to other singlet particles whose abundance has been neglected.
Neutrino masses and mixing in A5 with flavor antisymmetry
NASA Astrophysics Data System (ADS)
Joshipura, Anjan S.; Nath, Newton
2016-08-01
We discuss the consequences of assuming that the (Majorana) neutrino mass matrix Mν and the charged lepton mass matrix Ml satisfy SνTMνSν=-Mν and Tl†MlMl†Tl=MlMl† with respect to some discrete groups Sν and Tl contained in A5. These assumptions lead to a neutrino mass spectrum with two degenerate and one massless neutrino and also constrain mixing among them. We derive possible mixing patterns following from the choices Sν=Z2 , Z2×Z2 , and Tl=Z2,Z2×Z2,Z3,Z5 as subgroups of A5. One predicts the maximal atmospheric neutrino mixing angle θ23 and μ -τ reflection symmetry in a large number of cases, but it is also possible to obtain nonmaximal values for θ23. Only the third column of the neutrino mixing matrix can be obtained at the leading order due to degeneracy in masses of two of the neutrinos. We take up a specific example within the A5 group and identify Higgs vacuum expectation values which realize the above assumptions. Nonleading terms present in this example are shown to lead to splitting among degenerate pairs and a consistent description of both neutrino masses and mixing angles.
Massive neutrinos in the standard model and beyond
NASA Astrophysics Data System (ADS)
Thalapillil, Arun Madhav
The generation of the fermion mass hierarchy in the standard model of particle physics is a long-standing puzzle. The recent discoveries from neutrino physics suggests that the mixing in the lepton sector is large compared to the quark mixings. To understand this asymmetry between the quark and lepton mixings is an important aim for particle physics. In this regard, two promising approaches from the theoretical side are grand unified theories and family symmetries. In the first part of my thesis we try to understand certain general features of grand unified theories with Abelian family symmetries by taking the simplest SU(5) grand unified theory as a prototype. We construct an SU(5) toy model with U(1) F ⊗Z'2 ⊗Z'' 2⊗Z''' 2 family symmetry that, in a natural way, duplicates the observed mass hierarchy and mixing matrices to lowest approximation. The system for generating the mass hierarchy is through a Froggatt-Nielsen type mechanism. One idea that we use in the model is that the quark and charged lepton sectors are hierarchical with small mixing angles while the light neutrino sector is democratic with larger mixing angles. We also discuss some of the difficulties in incorporating finer details into the model without making further assumptions or adding a large scalar sector. In the second part of my thesis, the interaction of high energy neutrinos with weak gravitational fields is explored. The form of the graviton-neutrino vertex is motivated from Lorentz and gauge invariance and the non-relativistic interpretations of the neutrino gravitational form factors are obtained. We comment on the renormalization conditions, the preservation of the weak equivalence principle and the definition of the neutrino mass radius. We associate the neutrino gravitational form factors with specific angular momentum states. Based on Feynman diagrams, spin-statistics, CP invariance and symmetries of the angular momentum states in the neutrino-graviton vertex, we deduce
Neutrino Oscillation Parameter Sensitivity in Future Long-Baseline Experiments
Bass, Matthew
2014-01-01
The study of neutrino interactions and propagation has produced evidence for physics beyond the standard model and promises to continue to shed light on rare phenomena. Since the discovery of neutrino oscillations in the late 1990s there have been rapid advances in establishing the three flavor paradigm of neutrino oscillations. The 2012 discovery of a large value for the last unmeasured missing angle has opened the way for future experiments to search for charge-parity symmetry violation in the lepton sector. This thesis presents an analysis of the future sensitivity to neutrino oscillations in the three flavor paradigm for the T2K, NO A, LBNE, and T2HK experiments. The theory of the three flavor paradigm is explained and the methods to use these theoretical predictions to design long baseline neutrino experiments are described. The sensitivity to the oscillation parameters for each experiment is presented with a particular focus on the search for CP violation and the measurement of the neutrino mass hierarchy. The variations of these sensitivities with statistical considerations and experimental design optimizations taken into account are explored. The effects of systematic uncertainties in the neutrino flux, interaction, and detection predictions are also considered by incorporating more advanced simulations inputs from the LBNE experiment.
Hybrid textures of the right-handed Majorana neutrino mass matrix
NASA Astrophysics Data System (ADS)
Dev, S.; Gautam, Radha Raman; Singh, Lal
2013-08-01
We perform a systematic study of neutrino mass matrices having a vanishing cofactor and an equality between two cofactors of the mass matrix. Such texture structures of the effective neutrino mass matrix arise from the type-I seesaw mechanism when the Dirac neutrino mass matrix is diagonal with two equal elements and the right-handed Majorana neutrino mass matrix has hybrid textures with one equality of matrix elements and one zero matrix element. For three right-handed neutrinos there are sixty possible hybrid textures out of which only six are excluded by the present experimental data. We show that such textures can be derived using discrete symmetries. The predictions of experimentally allowed textures are examined for unknown parameters such as the effective Majorana mass of the electron neutrino and the Dirac-type CP-violating phase.
Charged Cosmic Rays and Neutrinos
NASA Astrophysics Data System (ADS)
Kachelrieß, M.
2013-04-01
High-energy neutrino astronomy has grown up, with IceCube as one of its main experiments having sufficient sensitivity to test "vanilla" models of astrophysical neutrinos. I review predictions of neutrino fluxes as well as the status of cosmic ray physics. I comment also briefly on an improvement of the Fermi-LAT limit for cosmogenic neutrinos and on the two neutrino events presented by IceCube first at "Neutrino 2012".
Paradoxes of neutrino oscillations
Akhmedov, E. Kh.; Smirnov, A. Yu.
2009-08-15
Despite the theory of neutrino oscillations being rather old, some of its basic issues are still being debated in the literature. We discuss a number of such issues, including the relevance of the 'same energy' and 'same momentum' assumptions, the role of quantum-mechanical uncertainty relations in neutrino oscillations, the dependence of the coherence and localization conditions that ensure the observability of neutrino oscillations on neutrino energy and momentum uncertainties, the question of (in)dependence of the oscillation probabilities on the neutrino production and detection processes, and the applicability limits of the stationary-source approximation. We also develop a novel approach to calculation of the oscillation probability in the wave-packet approach, based on the summation/integration conventions different from the standard one, which allows a new insight into the 'same energy' vs. 'same momentum' problem. We also discuss a number of apparently paradoxical features of the theory of neutrino oscillations.
Miramonti, Lino
2009-04-30
More than 40 years ago, neutrinos where conceived as a way to test the validity of the solar models which tell us that stars are powered by nuclear fusion reactions. The first measurement of the neutrino flux, in 1968 in the Homestake mine in South Dakota, detected only one third of the expected value, originating what has been known as the Solar Neutrino Problem. Different experiments were built in order to understand the origin of this discrepancy. Now we know that neutrinos undergo oscillation phenomenon changing their nature traveling from the core of the Sun to our detectors. In the work the 40 year long saga of the neutrino detection is presented; from the first proposals to test the solar models to last real time measurements of the low energy part of the neutrino spectrum.
A left-right symmetric flavor symmetry model
NASA Astrophysics Data System (ADS)
Rodejohann, Werner; Xu, Xun-Jie
2016-03-01
We discuss flavor symmetries in left-right symmetric theories. We show that such frameworks are a different environment for flavor symmetry model building compared to the usually considered cases. This does not only concern the need to obey the enlarged gauge structure, but also more subtle issues with respect to residual symmetries. Furthermore, if the discrete left-right symmetry is charge conjugation, potential inconsistencies between the flavor and charge conjugation symmetries should be taken care of. In our predictive model based on A_4 we analyze the correlations between the smallest neutrino mass, the atmospheric mixing angle and the Dirac CP phase, the latter prefers to lie around maximal values. There is no lepton flavor violation from the Higgs bi-doublet.
S3 × Bbb Z2 model for neutrino mass matrices
NASA Astrophysics Data System (ADS)
Grimus, Walter; Lavoura, Luís
2005-08-01
We propose a model for lepton mass matrices based on the seesaw mechanism, a complex scalar gauge singlet and a horizontal symmetry S3 × Bbb Z2. In a suitable weak basis, the charged-lepton mass matrix and the neutrino Dirac mass matrix are diagonal, but the vacuum expectation value of the scalar gauge singlet renders the Majorana mass matrix of the right-handed neutrinos non-diagonal, thereby generating lepton mixing. When the symmetry S3 is not broken in the scalar potential, the effective light-neutrino Majorana mass matrix enjoys μ-τ interchange symmetry, thus predicting maximal atmospheric neutrino mixing together with Ue3 = 0. A partial and less predictive form of μ-τ interchange symmetry is obtained when the symmetry S3 is softly broken in the scalar potential. Enlarging the symmetry group S3 × Bbb Z2 by an additional discrete electron-number symmetry Bbb Z2(e), a more predicitive model is obtained, which is in practice indistinguishable from a previous one based on the group D4.
Relativistic Pseudospin Symmetry
Ginocchio, Joseph N.
2011-05-06
We show that the pseudospin symmetry that Akito Arima discovered many years ago (with collaborators) is a symmetry of the the Dirac Hamiltonian for which the sum of the scalar and vector potentials are a constant. In this paper we discuss some of the implications of this relativistic symmetry and the experimental data that support these predictions. In his original paper Akito also discussed pseudo-U(3) symmetry. We show that pseudo-U(3) symmetry is a symmetry of the Dirac Hamiltonian for which the sum of harmonic oscillator vector and scalar potentials are equal to a constant, and we give the generators of pseudo-U(3) symmetry. Going beyond the mean field we summarize new results on non relativistic shell model Hamiltonians that have pseudospin symmetry and pseudo-orbital angular momentum symmetry as a dynamical symmetries.
Wong, Yvonne Y. Y.
2008-01-24
I give an overview of the effects of neutrinos on cosmology, focussing in particular on the role played by neutrinos in the evolution of cosmological perturbations. I discuss how recent observations of the cosmic microwave background and the large-scale structure of galaxies can probe neutrino masses with greater precision than current laboratory experiments. I describe several new techniques that will be used to probe cosmology in the future.
Lincoln, Don
2013-06-18
Dr. Don Lincoln introduces one of the most fascinating inhabitants of the subatomic realm: the neutrino. Neutrinos are ghosts of the microworld, almost not interacting at all. In this video, he describes some of their properties and how they were discovered. Studies of neutrinos are expected to be performed at many laboratories across the world and to form one of the cornerstones of the Fermilab research program for the next decade or more.
Lincoln, Don
2016-07-12
Dr. Don Lincoln introduces one of the most fascinating inhabitants of the subatomic realm: the neutrino. Neutrinos are ghosts of the microworld, almost not interacting at all. In this video, he describes some of their properties and how they were discovered. Studies of neutrinos are expected to be performed at many laboratories across the world and to form one of the cornerstones of the Fermilab research program for the next decade or more.
Federspiel, F.; Garvey, G.; Louis, W.C.; Mills, G.B.; Tayloe, R.; Sandberg, V.; Sapp, B.; White, D.H.
1999-07-09
The Liquid Scintillator Neutrino Detector (LSND), located at the LANSCE (formerly LAMPF) linear accelerator at Los Alamos National Laboratory, has seen evidence for the oscillation of neutrinos, and hence neutrino mass. That discovery was the impetus for this LDRD project, begun in 1996. The goal of this project was to define the appropriate technologies to use in a follow up experiment and to set in place the requirements for such an experiment.
Ichikawa, A. K.
2015-07-15
High-intensity proton accelerator complex enabled long baseline neutrino oscillation experiments with a precisely controlled neutrino beam. The beam power so far achieved is a few hundred kW with enourmorous efforts of accelerator physicists and engineers. However, to fully understand the lepton mixing structure, MW-class accelerators are desired. We describe the current intensity-frontier high-energy proton accelerators, their plans to go beyond and technical challenges in the neutrino beamline facilities.
SPheno 3.1: extensions including flavour, CP-phases and models beyond the MSSM
NASA Astrophysics Data System (ADS)
Porod, W.; Staub, F.
2012-11-01
high scale parameters by evaluating the corresponding renormalisation group equations. These parameters must be consistent with the requirement of correct electroweak symmetry breaking. The second issue is to use the obtained masses and couplings for calculating decay widths and branching ratios of supersymmetric particles as well as the cross sections for these particles in electron-positron annihilation. The third issue is to calculate low energy constraints in the B-meson sector such as BR(b s), MB s, rare lepton decays, such as BR(e), the SUSY contributions to anomalous magnetic moments and electric dipole moments of leptons, the SUSY contributions to the ρ parameter as well as lepton flavour violating Z decays. Solution method: The renormalisation connecting a high scale and the electroweak scale is calculated by the Runge-Kutta method. Iteration provides a solution consistent with the multi-boundary conditions. In case of three-body decays and for the calculation of initial state radiation Gaussian quadrature is used for the numerical solution of the integrals. Reasons for new version: Inclusion of new models as well as additional observables. Moreover, a new standard for data transfer had been established, which is now supported. Summary of revisions: The already existing models have been extended to include also CP-violation and flavour mixing. The data transfer is done using the so-called SLHA2 standard. In addition new models have been included: all three types of seesaw models as well as bilinear R-parity violation. Moreover, additional observables are calculated: branching ratios for flavour violating lepton decays, EDMs of leptons and of the neutron, CP-violating mass difference in the B-meson sector and branching ratios for flavour violating b-quark decays. Restrictions: In case of R-parity violation the cross sections are not calculated. Running time: 0.2 seconds on an Intel(R) Core(TM)2 Duo CPU T9900 with 3.06 GHz
Accelerator neutrino program at Fermilab
Parke, Stephen J.; /Fermilab
2010-05-01
The accelerator neutrino programme in the USA consists primarily of the Fermilab neutrino programme. Currently, Fermilab operates two neutrino beamlines, the Booster neutrino beamline and the NuMI neutrino beamline and is the planning stages for a third neutrino beam to send neutrinos to DUSEL. The experiments in the Booster neutrino beamline are miniBooNE, SciBooNE and in the future microBooNE, whereas in the NuMI beamline we have MINOS, ArgoNut, MINERVA and coming soon NOvA. The major experiment in the beamline to DUSEL will be LBNE.
Novel Ideas for Neutrino Beams
Peach, Ken
2007-04-23
Recent developments in neutrino physics, primarily the demonstration of neutrino oscillations in both atmospheric neutrinos and solar neutrinos, provide the first conclusive evidence for physics beyond the Standard Model of particle physics. The simplest phenomenology of neutrino oscillations, for three generations of neutrino, requires six parameters - two squared mass differences, 3 mixing angles and a complex phase that could, if not 0 or {pi}, contribute to the otherwise unexplained baryon asymmetry observed in the universe. Exploring the neutrino sector will require very intense beams of neutrinos, and will need novel solutions.
Favored Bc decay modes to search for a Majorana neutrino
NASA Astrophysics Data System (ADS)
Mandal, Sanjoy; Sinha, Nita
2016-08-01
Recently, the LHCb collaboration reported the observation of the decay mode Bc-→B¯s 0π- with the largest exclusive branching fraction amongst the known decay modes of all the B mesons. Here we propose a search for a few lepton-number violating (Δ L =2 ) decay modes of Bc which can only be induced by Majorana neutrinos. Distinguishing between Dirac and Majorana nature of neutrinos is an outstanding problem and hence, all possible searches for Majorana neutrinos need to be carried out. Since the lepton number violating modes are expected to be rare, when using meson decay modes for these searches one expects CKM favored modes to be the preferred ones; Bc→Bs is one such transition. With a resonance enhancement of the Majorana neutrino mediating the Bc-→B¯s 0ℓ1-ℓ2-π+ modes one can hope to observe these rare modes, or, even their nonobservation can be used to obtain tight constraints on the mixing angles of the heavy Majorana singlet with the light flavour neutrinos from upper limits of the branching fractions. Using these modes we obtain exclusion curves for the mixing angles which are tighter or compatible with results from earlier studies. However, we find that the relatively suppressed mode Bc-→J /ψ ℓ1- ℓ2-π+ can provide even tighter constraints on |Ve N|2, |Vμ N|2, |Ve NVμ N|, and in a larger range of the heavy neutrino mass. Further, exclusion regions for |Ve NVτ N|, |Vμ NVτ N| can also be obtained for masses larger than those accessible in tau decays. Upper limits on B (Bc-→π+ℓ1- ℓ2-) can also result in stringent exclusion curves for all the mixing elements, including that for |Vτ N|2 in a mass range where it is unconstrained thus far.
Gallagher, H.; Garvey, G.; Zeller, G.P.; /Fermilab
2011-01-01
The study of neutrino oscillations has necessitated a new generation of neutrino experiments that are exploring neutrino-nuclear scattering processes. We focus in particular on charged-current quasi-elastic scattering, a particularly important channel that has been extensively investigated both in the bubble-chamber era and by current experiments. Recent results have led to theoretical reexamination of this process. We review the standard picture of quasi-elastic scattering as developed in electron scattering, review and discuss experimental results, and discuss additional nuclear effects such as exchange currents and short-range correlations that may play a significant role in neutrino-nucleus scattering.
Cooperstein, J.
1986-10-01
The role of neutrinos in Type II supernovae is discussed. An overall view of the neutrino luminosity as expected theoretically is presented. The different weak interactions involved are assessed from the standpoint of how they exchange energy, momentum, and lepton number. Particular attention is paid to entropy generation and the path to thermal and chemical equilibration, and to the phenomenon of trapping. Various methods used to calculate the neutrino flows are considered. These include trapping and leakage schemes, distribution-averaged transfer, and multi-energy group methods. The information obtained from the neutrinos caught from Supernova 1987a is briefly evaluated. 55 refs., 7 figs.
NASA Technical Reports Server (NTRS)
Stanev, T.
1986-01-01
The first generation of large and precise detectors, some initially dedicated to search for nucleon decay has accumulated significant statistics on neutrinos and high-energy muons. A second generation of even better and bigger detectors are already in operation or in advanced construction stage. The present set of experimental data on muon groups and neutrinos is qualitatively better than several years ago and the expectations for the following years are high. Composition studies with underground muon groups, neutrino detection, and expected extraterrestrial neutrino fluxes are discussed.
Nonlinear growing neutrino cosmology
NASA Astrophysics Data System (ADS)
Ayaita, Youness; Baldi, Marco; Führer, Florian; Puchwein, Ewald; Wetterich, Christof
2016-03-01
The energy scale of dark energy, ˜2 ×10-3 eV , is a long way off compared to all known fundamental scales—except for the neutrino masses. If dark energy is dynamical and couples to neutrinos, this is no longer a coincidence. The time at which dark energy starts to behave as an effective cosmological constant can be linked to the time at which the cosmic neutrinos become nonrelativistic. This naturally places the onset of the Universe's accelerated expansion in recent cosmic history, addressing the why-now problem of dark energy. We show that these mechanisms indeed work in the growing neutrino quintessence model—even if the fully nonlinear structure formation and backreaction are taken into account, which were previously suspected of spoiling the cosmological evolution. The attractive force between neutrinos arising from their coupling to dark energy grows as large as 106 times the gravitational strength. This induces very rapid dynamics of neutrino fluctuations which are nonlinear at redshift z ≈2 . Nevertheless, a nonlinear stabilization phenomenon ensures only mildly nonlinear oscillating neutrino overdensities with a large-scale gravitational potential substantially smaller than that of cold dark matter perturbations. Depending on model parameters, the signals of large-scale neutrino lumps may render the cosmic neutrino background observable.
Bolometric detection of neutrinos
NASA Technical Reports Server (NTRS)
Cabrera, B.; Krauss, L. M.; Wilczek, F.
1985-01-01
Elastic neutrino scattering off electrons in crystalline silicon at 1-10 mK results in measurable temperature changes in macroscopic amounts of material, even for low-energy (less than 0.41-MeV) pp neutrinos from the sun. New detectors for bolometric measurement of low-energy neutrino interactions, including coherent nuclear elastic scattering, are proposed. A new and more sensitive search for oscillations of reactor antineutrinos is practical (about 100 kg of Si), and would lay the groundwork for a more ambitious measurement of the spectrum of pp, Be-7, and B-8 solar neutrinos, and of supernovae anywhere in the Galaxy (about 10 tons of Si).
Evidence for the role of cognitive resources in flavour-flavour evaluative conditioning.
Davies, Sarah R; El-Deredy, Wael; Zandstra, Elizabeth H; Blanchette, Isabelle
2012-01-01
One way that dis/likes are formed is through evaluative conditioning (EC). In two experiments we investigated the role of cognitive resources in flavour-flavour conditioning. Both experiments employed an EC procedure in which three novel flavoured conditioned stimuli (CSs) were consumed. One was consumed with a pleasant unconditioned stimulus (US; CS+ sugar), one with an aversive US (CS+ saline), and a third with plain water (CS-). Half of participants in each experiment performed a cognitive load task during conditioning. We measured EC using self-reported measures of liking (Experiments 1 and 2) and an indirect measure of liking: drink pick-up latency (Experiment 2). In both experiments, differential EC was observed in the no cognitive load condition but not in the cognitive load condition. This pattern of results was observed in self-reported measures of liking as well as in the drink pick-up latency data. Results from both experiments show that EC occurs only when there are sufficient cognitive resources available. The fact that this was observed using both self-reported and indirect measures suggests that insufficient cognitive resources affect learning itself rather than merely obstructing reporting.
Non-vanishing U e3 under S 3 symmetry
NASA Astrophysics Data System (ADS)
Siyeon, Kim
2012-07-01
This work proposes two models of neutrino masses that predict non-zero θ 13 under the non-Abelian discrete flavor symmetry {S}3⊗{Z}2. We advocate that the size of θ 13 is understood as a group theoretical consequence rather than a perturbed effect from the tri-bi-maximal mixing. So, the difference of two models is designed only in terms of the flavor symmetry, by changing the charge assignment of right-handed neutrinos. The PMNS matrix in the first model is obtained from both mass matrices, charged leptons giving rise to non-zero θl_{13} and neutrino masses giving rise to tri-bi-maximal mixing. The physical mixing angles are expressed by a simple relation between θl_{13} and tri-bi-maximal angles to fit the recent experimental results. The other model generates PMNS matrix with non-zero θ 13, only from the neutrino mass transformation. The 5-dimensional effective theory of Majorana neutrinos obtained in this framework is tested with phenomenological bounds in the parametric spaces sin θ 23,sin θ 12 and m 2/ m 3 vs. sin θ 13.
Enhanced lepton flavour violation in the supersymmetric inverse seesaw
NASA Astrophysics Data System (ADS)
Weiland, C.
2013-07-01
In minimal supersymmetric seesaw models, the contribution to lepton flavour violation from Z-penguins is usually negligible. In this study, we consider the supersymmetric inverse seesaw and show that, in this case, the Z-penguin contribution dominates in several lepton flavour violating observables due to the low scale of the inverse seesaw mechanism. Among the observables considered, we find that the most constraining one is the μ-e conversion rate which is already restricting the otherwise allowed parameter space of the model. Moreover, in this framework, the Z-penguins exhibit a non-decoupling behaviour, which has previously been noticed in lepton flavour violating Higgs decays.
Theoretical Results in Heavy Flavour Production
NASA Astrophysics Data System (ADS)
Kramer, G.
2011-05-01
We review one-particle inclusive production of heavy-flavoured hadrons in a framework which resums the large collinear logarithms through the evolution of the FFs and PDFs and retains the dependence on the heavy-quark mass. We focus on presenting results for the inclusive cross section for the production of charmed mesons in pp¯ collisions and the comparison with CDF data as well as on inclusive B-meson production and comparison with recent CDF data, for which in both new determined fragmentation functions have been used. We asses the sensitivity of CDF data of D inclusive production to the internal charm parametrization given by Pumplin et al. [J. Pumplin, H. L. Lai and W. K. Tung, Phys. Rev. D75, 054029 (2007)].
Supersymmetry and the calculation of neutrino masses
NASA Astrophysics Data System (ADS)
Aulakh, C. S.; Mohapatra, R. N.
1983-01-01
We point out that in a recently proposed supersymmetric extension of the standard SU(2)L X U(1) model where global lepton number symmetry is spontaneously broken, the neutrino masses are computable as a higher order effect and are small, without the need for an accompanying heavy (or superheavy) right-handed neutral lepton. The neutrino masses in this picture are inversely proportional to the scale of supersymmetry breaking and are expected to be in the range of 10-7-10-5 eV for reasonable choice of parameters. Work supported in part by National Science Foundation Grant No. PHY-78-24888 and CUNY-PSC-BHE Faculty Research Award.
Charged Lepton Flavour Violation in Littlest Higgs model with T-parity
Gaur, Naveen
2008-02-21
The Little Higgs model with T-parity (LHT) belongs to the non-minimal flavour violating model. This model has new sources of flavour and CP violation both in quark and leptonic sectors. These new sources of flavour violation originates by the interaction of Standard Model (SM) fermions with heavy gauge bosons and heavy (or mirror) fermions. In this work we will present the impact of the new flavour structure of T-parity models on flavour violations in leptonic sector.
Supersymmetric parameter space of family symmetries
Velasco-Sevilla, L.
2008-11-23
In this talk I have emphasized the effects of considering departures from the minimal flavour violation conditions, in the context of CMSSM-like theories, introduced by boundary conditions at GUT scale from Family Symmetries. In [1] we have shown the results of running these conditions down to EW, where constraints from fermion masses and CKM matrix elements have been used. Only when the expansion parameter in the sdown-squark sector is relatively large it is possible to relax the lower limit from b{yields}s{gamma} on the universal gaugino mass. The expansion parameter associated with the slepton sector needs to be smaller than the analogous in the sdown-squark sector in order to satisfy the bound imposed by the decay of {tau}{yields}{mu}{mu}.
Self-induced flavor conversion of supernova neutrinos on small scales
NASA Astrophysics Data System (ADS)
Chakraborty, S.; Hansen, R. S.; Izaguirre, I.; Raffelt, G. G.
2016-01-01
Self-induced flavor conversion of supernova (SN) neutrinos is a generic feature of neutrino-neutrino dispersion. The corresponding run-away modes in flavor space can spontaneously break the original symmetries of the neutrino flux and in particular can spontaneously produce small-scale features as shown in recent schematic studies. However, the unavoidable ``multi-angle matter effect'' shifts these small-scale instabilities into regions of matter and neutrino density which are not encountered on the way out from a SN. The traditional modes which are uniform on the largest scales are most prone for instabilities and thus provide the most sensitive test for the appearance of self-induced flavor conversion. As a by-product we clarify the relation between the time evolution of an expanding neutrino gas and the radial evolution of a stationary SN neutrino flux. Our results depend on several simplifying assumptions, notably stationarity of the solution, the absence of a ``backward'' neutrino flux caused by residual scattering, and global spherical symmetry of emission.
Self-induced flavor conversion of supernova neutrinos on small scales
Chakraborty, S.; Izaguirre, I.; Raffelt, G.G.; Hansen, R. S. E-mail: rshansen@phys.au.dk E-mail: raffelt@mpp.mpg.de
2016-01-01
Self-induced flavor conversion of supernova (SN) neutrinos is a generic feature of neutrino-neutrino dispersion. The corresponding run-away modes in flavor space can spontaneously break the original symmetries of the neutrino flux and in particular can spontaneously produce small-scale features as shown in recent schematic studies. However, the unavoidable ''multi-angle matter effect'' shifts these small-scale instabilities into regions of matter and neutrino density which are not encountered on the way out from a SN. The traditional modes which are uniform on the largest scales are most prone for instabilities and thus provide the most sensitive test for the appearance of self-induced flavor conversion. As a by-product we clarify the relation between the time evolution of an expanding neutrino gas and the radial evolution of a stationary SN neutrino flux. Our results depend on several simplifying assumptions, notably stationarity of the solution, the absence of a ''backward'' neutrino flux caused by residual scattering, and global spherical symmetry of emission.
The HARP Hadron Production Experiment and Its Significance for Neutrino Factory Design
NASA Astrophysics Data System (ADS)
Howlett, L. C.
2004-03-01
A neutrino factory would provide a high flux beam of electron and muon neutrinos with well understood energy and flavour composition for detailed studies of neutrino oscillations. Such a beam requires a large number of muons and hence pions, which would be provided by a proton driver and pion production target. The optimal design of such a pion production target and the necessary pion capture system need accurate knowledge of hadron production at energies of several GeV. HARP, a large acceptance particle spectrometer of conventional design, aims to measure hadron production cross sections on thin and thick nuclear targets in the range of beam momentum 2-15 GeV/c in order to provide the desired data.
Extremely high energy cosmic neutrinos and relic neutrinos
Quigg, Chris; /Fermilab /CERN
2006-03-01
I review the essentials of ultrahigh-energy neutrino interactions, show how neutral-current detection and flavor tagging can enhance the scientific potential of neutrino telescopes, and sketch new studies on neutrino encounters with dark matter relics and on gravitational lensing of neutrinos.
Review of neutrino oscillations with sterile and active neutrinos
NASA Astrophysics Data System (ADS)
Kisslinger, Leonard S.
2016-08-01
Recently neutrino oscillation experiments have shown that it is very likely that there are one or two sterile neutrinos. In this review neutrino oscillations with one, two, three sterile and three active neutrinos, and parameters that are consistent with experiments, are reviewed.
Aad, G.; Abbott, B.; Abdallah, J.; Abdinov, O.; Aben, R.; Abolins, M.; AbouZeid, O. S.; Abramowicz, H.; Abreu, H.; Abreu, R.; et al
2016-01-29
A search for single top-quark production via flavour-changing neutral current processes from gluon plus up- or charm-quark initial states in proton–proton collisions at the LHC is presented. Data collected with the ATLAS detector in 2012 at a centre-of-mass energy of 8 TeV and corresponding to an integrated luminosity of 20.3 fb–1 are used. Furthermore, candidate events for a top quark decaying into a lepton, a neutrino and a jet are selected and classified into signal- and background-like candidates using a neural network.
PREFACE: Symmetries in Science XV
NASA Astrophysics Data System (ADS)
Schuch, Dieter; Ramek, Michael
2012-08-01
Logo Bregenz, the peaceful monastery of Mehrerau and the Opera on the Floating Stage again provided the setting for the international symposium 'Symmetries in Science'. The series which has been running for more than 30 years brings together leading theoreticians whose area of research is, in one way or another, related to symmetry. Since 1992 the meeting took place biannually in Brengez until 2003. In 2009, with the endorsement of the founder, Professor Bruno Gruber, we succeeded in re-establishing the series without external funding. The resounding success of that meeting encouraged us to continue in 2011 and, following on the enthusiasm and positive feedback of the participants, we expect to continue in 2013. Yet again, our meeting in 2011 was very international in flavour and brought together some 30 participants representing 12 nationalities, half of them from countries outside the European Union (from New Zealand to Mexico, Russia to Israel). The broad spectrum, a mixture of experienced experts and highly-motivated newcomers, the intensive exchange of ideas in a harmonious and relaxed atmosphere and the resulting joint projects are probably the secrets of why this meeting is considered to be so special to its participants. At the resumption in 2009 some leading experts and younger scientists from economically weak countries were unable to attend due to the lack of financial resources. This time, with the very worthy and unbureaucratic support of the 'Vereinigung von Freunden und Förderern der J W Goethe-Universität Frankfurt am Main' (in short: 'Friends and Supporters of the Frankfurt University'), it was possible for all candidates to participate. In particular some young, inspired scientists had the chance of presenting their work to a very competent, but also friendly, audience. We wish to thank the 'Freunde und Förderer' for supporting Symmetries in Science XV. Almost all participants contributed to the publication of this Conference Proceedings. There
Cosmological neutrino mass detection: The Best probe of neutrino lifetime
Serpico, Pasquale D.; /Fermilab
2007-01-01
Future cosmological data may be sensitive to the effects of a finite sum of neutrino masses even as small as {approx}0.06 eV, the lower limit guaranteed by neutrino oscillation experiments. We show that a cosmological detection of neutrino mass at that level would improve by many orders of magnitude the existing limits on neutrino lifetime, and as a consequence on neutrino secret interactions with (quasi-)massless particles as in majoron models. On the other hand, neutrino decay may provide a way-out to explain a discrepancy {approx}< 0.1 eV between cosmic neutrino bounds and Lab data.
A Variable-Flavour-Number Scheme at NNLO
Thorne, Robert S.
2005-10-06
I present a formulation of a Variable Flavour Number Scheme for heavy quarks that is implemented up to NNLO in the strong coupling constant and may be used in NNLO global fits for parton distributions.
Can we see tau-Flavour Violation at the LHC?
Carquin, E.; Gomez, M. E.; Rodriguez-Quintero, J.
2010-02-10
We study the conditions required for chi{sub 2}->chi+tau{sup +}-mu{sup +}- decays to yield observable tau flavour violation at the LHC, for cosmologically interesting values of the neutralino relic density.
Monte Carlo neutrino oscillations
Kneller, James P.; McLaughlin, Gail C.
2006-03-01
We demonstrate that the effects of matter upon neutrino propagation may be recast as the scattering of the initial neutrino wave function. Exchanging the differential, Schrodinger equation for an integral equation for the scattering matrix S permits a Monte Carlo method for the computation of S that removes many of the numerical difficulties associated with direct integration techniques.
NASA Technical Reports Server (NTRS)
Edwards, P. G.; Protheroe, R. J.
1985-01-01
The result of a new calculation of the atmospheric muon and neutrino fluxes and the energy spectrum of muon-neutrinos produced in individual extensive air showers (EAS) initiated by proton and gamma-ray primaries is reported. Also explained is the possibility of detecting atmospheric nu sub mu's due to gamma-rays from these sources.
Physics of neutrino flavor transformation through matter-neutrino resonances
NASA Astrophysics Data System (ADS)
Wu, Meng-Ru; Duan, Huaiyu; Qian, Yong-Zhong
2016-01-01
In astrophysical environments such as core-collapse supernovae and neutron star-neutron star or neutron star-black hole mergers where dense neutrino media are present, matter-neutrino resonances (MNRs) can occur when the neutrino propagation potentials due to neutrino-electron and neutrino-neutrino forward scattering nearly cancel each other. We show that neutrino flavor transformation through MNRs can be explained by multiple adiabatic solutions similar to the Mikheyev-Smirnov-Wolfenstein mechanism. We find that for the normal neutrino mass hierarchy, neutrino flavor evolution through MNRs can be sensitive to the shape of neutrino spectra and the adiabaticity of the system, but such sensitivity is absent for the inverted hierarchy.
Feynman rules for neutrinos and new neutralinos in the BLMSSM
NASA Astrophysics Data System (ADS)
Dong, Xing-Xing; Zhao, Shu-Min; Zhang, Hai-Bin; Wang, Fang; Feng, Tai-Fu
2016-09-01
In a supersymmetric extension of the Standard Model where baryon and lepton numbers are local gauge symmetries (BLMSSM), we deduce the Feynman rules for neutrinos and new neutralinos. We briefly introduce the mass matrices for the particles and the related couplings in this work, which are very useful to research the neutrinos and new neutralinos. Supported by Major Project of NNSFC (11535002) and NNSFC (11275036), Natural Science Foundation of Hebei Province (A2016201010), and Foundation of Hebei Province (BR2-201), and the Natural Science Fund of Hebei University (2011JQ05, 2012-242), Hebei Key Lab of Optic-Electronic Information and Materials, Midwest Universities Comprehensive Strength Promotion Project
New Stringy Instanton Effects And Neutrino Majorana Masses
Cvetic, M.; Richter, R.; Weigand, T.
2007-10-03
D-brane instantons can generate open string couplings in the superpotential which violate global abelian symmetries and are therefore perturbatively forbidden. After discussing the main ingredients, focussing for concretenes on Type IIA orientifold compactifications, we exemplify the computation of instanton-induced Majorana mass terms for right-handed neutrinos in a local SU(5) GUT-like model. In particular, we show that the instanton allows for naturally engineering the intermediate scale of the Majorana masses, thereby realizing the seesaw mechanism for neutrinos.
A gauge model for right handed neutrinos as dark matter
NASA Astrophysics Data System (ADS)
Hernández-Pinto, R. J.; Pérez-Lorenzana, A.
2008-07-01
We suggest a simple extension of the electroweak group, SU(2)L×U(1)Y×U(1)B-L, where the breaking of U(1)B-L symmetry provides masses for right handed neutrinos, N, at an acceptable range for them to be Dark Matter (DM). We study the contributions to Mo/ller and Bhabha scattering due to B-L neutral boson to constrain its gauge coupling. We analize N decay rates to determine the number of families that should be considered as DM candidates. The decoupling temperature between active and sterile neutrinos is also calculated.
Testing atmospheric mixing sum rules at precision neutrino facilities
NASA Astrophysics Data System (ADS)
Ballett, Peter; King, Stephen F.; Luhn, Christoph; Pascoli, Silvia; Schmidt, Michael A.
2014-01-01
We study the prospects for testing classes of atmospheric mixing sum rules at precision neutrino facilities. Such sum rules, which correlate the atmospheric mixing angle θ23 with the recently measured reactor angle θ13 and the cosine of the oscillation phase δ, are predicted by a variety of semidirect models based on discrete family symmetry classified in terms of finite von Dyck groups. We perform a detailed simulation of the performance of the next generation of oscillation experiments, including the wideband superbeam and low-energy neutrino factory proposals, and compare their discriminating power for testing atmospheric mixing sum rules.
Semidirect product groups, vacuum alignment, and tribimaximal neutrino mixing
Babu, K. S.; Gabriel, S.
2010-10-01
The neutrino oscillation data are in very good agreement with the tribimaximal mixing pattern: sin{sup 2{theta}}{sub 23}=1/2, sin{sup 2{theta}}{sub 12}=1/3, and sin{sup 2{theta}}{sub 13}=0. Attempts to generate this pattern based on finite family symmetry groups typically assume that the family symmetry is broken into different subgroups in the charged-lepton and the neutrino mass matrices. This leads to a technical problem, where the cross couplings between the Higgs fields responsible for the two symmetry breaking chains force their vacuum expectation values to align, upsetting the desired breaking pattern. Here, we present a class of models based on the semidirect product group (S{sub 3}){sup 4}xA{sub 4}, where the lepton families belong to representations which are not faithful. In effect, the Higgs sector knows about the full symmetry while the lepton sector knows only about the A{sub 4} factor group. This can solve the alignment problem without altering the desired properties of the family symmetry. Inclusion of quarks into the framework is straightforward and leads to small and arbitrary Cabibbo-Kobayashi-Maskawa mixing angles. Supersymmetry is not essential for our proposal, but the model presented is easily supersymmetrized, in which case the same family symmetry solves the supersymmetry flavor problem.
Contact sensitivity to flavourings and perfumes in atopic dermatitis.
Abifadel, R; Mortureux, P; Perromat, M; Ducombs, G; Taieb, A
1992-07-01
16 children with atopic dermatitis and 4 nonatopics were skin tested with flavourings and perfumes. Immediate reactions to balsam of Peru and fragrance-mix were found in 9 atopics, and none among nonatopics. An irritant is more probable than an immunologic mechanism. Allergen solutions should probably be assayed at a lower concentration in atopic patients. This study points to a possible aggravating factor from perfumes and flavourings ingested, inhaled, or used as cosmetics.
The Sudbury Neutrino Observatory
NASA Astrophysics Data System (ADS)
Bellerive, A.; Klein, J. R.; McDonald, A. B.; Noble, A. J.; Poon, A. W. P.
2016-07-01
This review paper provides a summary of the published results of the Sudbury Neutrino Observatory (SNO) experiment that was carried out by an international scientific collaboration with data collected during the period from 1999 to 2006. By using heavy water as a detection medium, the SNO experiment demonstrated clearly that solar electron neutrinos from 8B decay in the solar core change into other active neutrino flavors in transit to Earth. The reaction on deuterium that has equal sensitivity to all active neutrino flavors also provides a very accurate measure of the initial solar flux for comparison with solar models. This review summarizes the results from three phases of solar neutrino detection as well as other physics results obtained from analyses of the SNO data.
Ibarra, Alejandro
2015-07-15
Neutrinos could be key particles to unravel the nature of the dark matter of the Universe. On the one hand, sterile neutrinos in minimal extensions of the Standard Model are excellent dark matter candidates, producing potentially observable signals in the form of a line in the X-ray sky. On the other hand, the annihilation or the decay of dark matter particles produces, in many plausible dark matter scenarios, a neutrino flux that could be detected at neutrino telescopes, thus providing non-gravitational evidence for dark matter. More conservatively, the non-observation of a significant excess in the neutrino fluxes with respect to the expected astrophysical backgrounds can be used to constrain dark matter properties, such as the self-annihilation cross section, the scattering cross section with nucleons and the lifetime.
Bowles, T.J.; Brice, S.J.; Esch, E.-I.; Fowler, M.M.; Goldschmidt, A.; Hime, A.; McGirt, F.; Miller, G.G.; Thornewell, P.M.; Wilhelmy, J.B.; Wouters, J.M.
1999-07-15
With its heavy water target, the Sudbury Neutrino Observatory (SNO) offers the unique opportunity to measure both the 8B flux of electron neutrinos from the Sun and, independently, the flux of all active neutrino species reaching the Earth. A model-independent test of the hypothesis that neutrino oscillations are responsible for the observed solar neutrino deficit can be made by comparing the charged-current (CC) and neutral-current (NC) rates. This LDRD proposal supported the research and development necessary for an assessment of backgrounds and performance of the SNO detector and the ability to extract the NC/CC-Ratio. Particular emphasis is put upon the criteria for deployment and signal extraction from a discrete NC detector array based upon ultra-low background 3He proportional counters.
NASA Astrophysics Data System (ADS)
Brading, Katherine; Castellani, Elena
2003-12-01
Preface; Copyright acknowledgements; List of contributors; 1. Introduction; Part I. Continuous Symmetries: 2. Classic texts: extracts from Weyl and Wigner; 3. Review paper: On the significance of continuous symmetry to the foundations of physics C. Martin; 4. The philosophical roots of the gauge principle: Weyl and transcendental phenomenological idealism T. Ryckman; 5. Symmetries and Noether's theorems K. A. Brading and H. R. Brown; 6. General covariance, gauge theories, and the Kretschmann objection J. Norton; 7. The interpretation of gauge symmetry M. Redhead; 8. Tracking down gauge: an ode to the constrained Hamiltonian formalism J. Earman; 9. Time-dependent symmetries: the link between gauge symmetries and indeterminism D. Wallace; 10. A fourth way to the Aharanov-Bohm effect A. Nounou; Part II. Discrete Symmetries: 11. Classic texts: extracts from Lebniz, Kant and Black; 12. Review paper: Understanding permutation symmetry S. French and D. Rickles; 13. Quarticles and the identity of discernibles N. Hugget; 14. Review paper: Handedness, parity violation, and the reality of space O. Pooley; 15. Mirror symmetry: what is it for a relational space to be orientable? N. Huggett; 16. Physics and Leibniz's principles S. Saunders; Part III. Symmetry Breaking: 17: Classic texts: extracts from Curie and Weyl; 18. Extract from G. Jona-Lasinio: Cross-fertilization in theoretical physics: the case of condensed matter and particle physics G. Jona-Lasinio; 19. Review paper: On the meaning of symmetry breaking E. Castellani; 20. Rough guide to spontaneous symmetry breaking J. Earman; 21. Spontaneous symmetry breaking: theoretical arguments and philosophical problems M. Morrison; Part IV. General Interpretative Issues: 22. Classic texts: extracts from Wigner; 23. Symmetry as a guide to superfluous theoretical structure J. Ismael and B. van Fraassen; 24. Notes on symmetries G. Belot; 25. Symmetry, objectivity, and design P. Kosso; 26. Symmetry and equivalence E. Castellani.
NASA Astrophysics Data System (ADS)
Brading, Katherine; Castellani, Elena
2010-01-01
Preface; Copyright acknowledgements; List of contributors; 1. Introduction; Part I. Continuous Symmetries: 2. Classic texts: extracts from Weyl and Wigner; 3. Review paper: On the significance of continuous symmetry to the foundations of physics C. Martin; 4. The philosophical roots of the gauge principle: Weyl and transcendental phenomenological idealism T. Ryckman; 5. Symmetries and Noether's theorems K. A. Brading and H. R. Brown; 6. General covariance, gauge theories, and the Kretschmann objection J. Norton; 7. The interpretation of gauge symmetry M. Redhead; 8. Tracking down gauge: an ode to the constrained Hamiltonian formalism J. Earman; 9. Time-dependent symmetries: the link between gauge symmetries and indeterminism D. Wallace; 10. A fourth way to the Aharanov-Bohm effect A. Nounou; Part II. Discrete Symmetries: 11. Classic texts: extracts from Lebniz, Kant and Black; 12. Review paper: Understanding permutation symmetry S. French and D. Rickles; 13. Quarticles and the identity of discernibles N. Hugget; 14. Review paper: Handedness, parity violation, and the reality of space O. Pooley; 15. Mirror symmetry: what is it for a relational space to be orientable? N. Huggett; 16. Physics and Leibniz's principles S. Saunders; Part III. Symmetry Breaking: 17: Classic texts: extracts from Curie and Weyl; 18. Extract from G. Jona-Lasinio: Cross-fertilization in theoretical physics: the case of condensed matter and particle physics G. Jona-Lasinio; 19. Review paper: On the meaning of symmetry breaking E. Castellani; 20. Rough guide to spontaneous symmetry breaking J. Earman; 21. Spontaneous symmetry breaking: theoretical arguments and philosophical problems M. Morrison; Part IV. General Interpretative Issues: 22. Classic texts: extracts from Wigner; 23. Symmetry as a guide to superfluous theoretical structure J. Ismael and B. van Fraassen; 24. Notes on symmetries G. Belot; 25. Symmetry, objectivity, and design P. Kosso; 26. Symmetry and equivalence E. Castellani.
Flavored leptogenesis with quasidegenerate neutrinos in a broken cyclic symmetric model
NASA Astrophysics Data System (ADS)
Adhikary, Biswajit; Chakraborty, Mainak; Ghosal, Ambar
2016-06-01
Cyclic symmetry in the neutrino sector with the type-I seesaw mechanism in the mass basis of charged leptons and right chiral neutrinos (Ni R, i =e , μ , τ ) generates a twofold degenerate light neutrino and a threefold degenerate heavy neutrino mass spectrum. Consequently, such a scheme produces vanishing one light neutrino mass squared difference and lepton asymmetry. To circumvent such an unphysical outcome, we break cyclic symmetry in the diagonal right chiral neutrino mass term by a small breaking parameter. Nonzero mass squared differences and mixing angles are generated with the help of the small breaking parameter. The smallness of the breaking parameter opens up the possibility of resonant leptogenesis. Assuming complex Yukawa couplings, we derive generalized expressions with flavor-dependent C P asymmetry parameters (ɛiα ) which are valid for the quasidegenerate as well as hierarchical mass spectrum of right-handed neutrinos. Thereafter, we set up the chain of coupled Boltzmann equations (which are flavor dependent too) which have to be solved in order to get the final lepton asymmetries. Depending upon the temperature regime, the C P asymmetries and the Boltzmann equations may also be flavor independent. As our goal is to study the enhancement of C P asymmetry due to the quasidegeneracy of right-handed neutrinos, we select only the lowest allowed (by neutrino oscillation data) value of the breaking parameter (and other corresponding Lagrangian parameters) and estimate the baryon asymmetry parameter YB. The experimental constraint of YB introduces a bound on right-handed neutrino mass which remained unrestricted by neutrino oscillation data.
Search for eV sterile neutrinos at a nuclear reactor — the Stereo project
NASA Astrophysics Data System (ADS)
Haser, J.; Stereo Collaboration
2016-05-01
The re-analyses of the reference spectra of reactor antineutrinos together with a revised neutrino interaction cross section enlarged the absolute normalization of the predicted neutrino flux. The tension between previous reactor measurements and the new prediction is significant at 2.7 σ and is known as “reactor antineutrino anomaly”. In combination with other anomalies encountered in neutrino oscillation measurements, this observation revived speculations about the existence of a sterile neutrino in the eV mass range. Mixing of this light sterile neutrino with the active flavours would lead to a modification of the detected antineutrino flux. An oscillation pattern in energy and space could be resolved by a detector at a distance of few meters from a reactor core: the neutrino detector of the Stereo project will be located at about 10 m distance from the ILL research reactor in Grenoble, France. Lengthwise separated in six target cells filled with 2 m3 Gd-loaded liquid scintillator in total, the experiment will search for a position-dependent distortion in the energy spectrum.
Astroparticle physics with solar neutrinos
NAKAHATA, Masayuki
2011-01-01
Solar neutrino experiments observed fluxes smaller than the expectations from the standard solar model. This discrepancy is known as the “solar neutrino problem”. Flux measurements by Super-Kamiokande and SNO have demonstrated that the solar neutrino problem is due to neutrino oscillations. Combining the results of all solar neutrino experiments, parameters for solar neutrino oscillations are obtained. Correcting for the effect of neutrino oscillations, the observed neutrino fluxes are consistent with the prediction from the standard solar model. In this article, results of solar neutrino experiments are reviewed with detailed descriptions of what Kamiokande and Super-Kamiokande have contributed to the history of astroparticle physics with solar neutrino measurements. PMID:21558758
Astroparticle physics with solar neutrinos.
Nakahata, Masayuki
2011-01-01
Solar neutrino experiments observed fluxes smaller than the expectations from the standard solar model. This discrepancy is known as the "solar neutrino problem". Flux measurements by Super-Kamiokande and SNO have demonstrated that the solar neutrino problem is due to neutrino oscillations. Combining the results of all solar neutrino experiments, parameters for solar neutrino oscillations are obtained. Correcting for the effect of neutrino oscillations, the observed neutrino fluxes are consistent with the prediction from the standard solar model. In this article, results of solar neutrino experiments are reviewed with detailed descriptions of what Kamiokande and Super-Kamiokande have contributed to the history of astroparticle physics with solar neutrino measurements. (Communicated by Toshimitsu Yamazaki, M.J.A.).
Neutrino mass as the probe of intermediate mass scales
Senjanovic, G.
1980-01-01
A discussion of the calculability of neutrino mass is presented. The possibility of neutrinos being either Dirac or Majorana particles is analyzed in detail. Arguments are offered in favor of the Majorana case: the smallness of neutrino mass is linked to the maximality of parity violation in weak interactions. It is shown how the measured value of neutrino mass would probe the existence of an intermediate mass scale, presumably in the TeV region, at which parity is supposed to become a good symmetry. Experimental consequences of the proposed scheme are discussed, in particular the neutrino-less double ..beta.. decay, where observation would provide a crucial test of the model, and rare muon decays such as ..mu.. ..-->.. e..gamma.. and ..mu.. ..-->.. ee anti e. Finally, the embedding of this model in an O(10) grand unified theory is analyzed, with the emphasis on the implications for intermediate mass scales that it offers. It is concluded that the proposed scheme provides a distinct and testable alternative for understanding the smallness of neutrino mass. 4 figures.
Shedding light on neutrino masses with dark forces
Batell, Brian; Pospelov, Maxim; Shuve, Brian
2016-08-08
Heavy right-handed neutrinos, N , provide the simplest explanation for the origin of light neutrino masses and mixings. If MN is at or below the weak scale, direct experimental discovery of these states is possible at accelerator experiments such as the LHC or new dedicated beam dump experiments; in these experiments, N decays after traversing a macroscopic distance from the collision point. The experimental sensitivity to right-handed neutrinos is significantly enhanced if there is a new “dark” gauge force connecting them to the Standard Model (SM), and detection of N can be the primary discovery mode for the new darkmore » force itself. We take the well-motivated example of a B – L gauge symmetry and analyze the sensitivity to displaced decays of N produced via the new gauge interaction in two experiments: the LHC and the proposed SHiP beam dump experiment. In the most favorable case in which the mediator can be produced on-shell and decays to right handed neutrinos (pp → X + VB–L → X + N N ), the sensitivity reach is controlled by the square of the B – L gauge coupling. Here, we demonstrate that these experiments could access neutrino parameters responsible for the observed SM neutrino masses and mixings in the most straightforward implementation of the see-saw mechanism.« less
Shedding light on neutrino masses with dark forces
NASA Astrophysics Data System (ADS)
Batell, Brian; Pospelov, Maxim; Shuve, Brian
2016-08-01
Heavy right-handed neutrinos, N , provide the simplest explanation for the origin of light neutrino masses and mixings. If M N is at or below the weak scale, direct experimental discovery of these states is possible at accelerator experiments such as the LHC or new dedicated beam dump experiments; in these experiments, N decays after traversing a macroscopic distance from the collision point. The experimental sensitivity to right-handed neutrinos is significantly enhanced if there is a new "dark" gauge force connecting them to the Standard Model (SM), and detection of N can be the primary discovery mode for the new dark force itself. We take the well-motivated example of a B - L gauge symmetry and analyze the sensitivity to displaced decays of N produced via the new gauge interaction in two experiments: the LHC and the proposed SHiP beam dump experiment. In the most favorable case in which the mediator can be produced on-shell and decays to right handed neutrinos ( pp → X + V B- L → X + N N ), the sensitivity reach is controlled by the square of the B - L gauge coupling. We demonstrate that these experiments could access neutrino parameters responsible for the observed SM neutrino masses and mixings in the most straightforward implementation of the see-saw mechanism.
Geometric intrinsic symmetries
Gozdz, A. Szulerecka, A.; Pedrak, A.
2013-08-15
The problem of geometric symmetries in the intrinsic frame of a many-body system (nucleus) is considered. An importance of symmetrization group notion is discussed. Ageneral structure of the intrinsic symmetry group structure is determined.
Predicting charged lepton flavor violation from 3-3-1 gauge symmetry
NASA Astrophysics Data System (ADS)
Boucenna, Sofiane M.; Valle, José W. F.; Vicente, Avelino
2015-09-01
The simplest realization of the inverse seesaw mechanism in a S U (3 )C⊗S U (3 )L⊗U (1 )X gauge theory offers striking flavor correlations between rare charged lepton flavor violating decays and the measured neutrino oscillations parameters. The predictions follow from the gauge structure itself without the need for any flavor symmetry. Such tight complementarity between charged lepton flavor violation and neutrino oscillations renders the scenario strictly testable.
A search for sterile neutrinos at the MINOS experiment
Pittam, Robert Neil
2010-01-01
MINOS is a long baseline neutrino oscillation experiment based at the Fermi National Accelerator Laboratory in Illinois, USA. The experiment was designed to study neutrino oscillation phenomena. The v_{μ} beam produced by the NuMI beam facility at FNAL is used along with two functionally identical detectors. The Near Detector at FNAL and a Far Detector 735 km away in the Soudan Underground Laboratory in northern Minnesota. Comparison of the observed spectra of neutrinos at the two detectors provides the evidence for neutrino oscillations. This thesis presents work on the postulated phenomena of sterile neutrinos. Oscillations between active and sterile neutrinos will lead to a deficit in the expected rate of measured Neutral Current interactions at the Far Detector. A technique for selecting Neutral Current events utilizing an Artificial Neural Network is presented with resulting overall efficiency of 91.1% and purity of 66.0%. A method of predicting the expected Charged and Neutral Current energy spectra at the Far Detector given the data recorded at the Near Detector is presented. A model to search for oscillations between sterile and active neutrinos is developed. Sources of systematic uncertainty that can effect the results of the analysis are discussed. The analysis developed is applied to a Standard Model 3 flavour oscillation model as a cross check under the scenarios with and without v_{e} appearance. The oscillation parameters measured by this model are Δm_{32}^{2} = (2.39_{-0.15}^{+0.23}) x 10^{-3} eV^{2} and θ_{23} = 0.727_{-0.11}^{+0.22} for the no v_{e} appearance result. An analysis of the resulting prediction reveals no evidence for active neutrino disappearance. The analysis is then performed using the 4 flavour neutrino oscillation model developed. Again this is done under the 2 scenarios of v_{e} appearance and no v_{e} appearance
Coherent scattering of cosmic neutrinos
NASA Technical Reports Server (NTRS)
Opher, R.
1974-01-01
It is shown that cosmic neutrino scattering can be non-negligible when coherence effects previously neglected are taken into account. The coherent neutrino scattering cross section is derived and the neutrino index of refraction evaluated. As an example of coherent neutrino scattering, a detector using critical reflection is described which in principle can detect the low energy cosmic neutrino background allowed by the measured cosmological red shift.
Neutrino-neutrino interactions in a supernova and their effect on neutrino flavor conversions
Dighe, Amol
2011-11-23
The neutrino-neutrino interactions inside a supernova core give rise to nonlinear collective effects that significantly influence the neutrino flavor conversions inside the star. I shall describe these interactions, the new oscillation phenomena they generate, and their effect on the neutrino fluxes arriving at the earth.
Polynomial Graphs and Symmetry
ERIC Educational Resources Information Center
Goehle, Geoff; Kobayashi, Mitsuo
2013-01-01
Most quadratic functions are not even, but every parabola has symmetry with respect to some vertical line. Similarly, every cubic has rotational symmetry with respect to some point, though most cubics are not odd. We show that every polynomial has at most one point of symmetry and give conditions under which the polynomial has rotational or…
Chiral symmetry and chiral-symmetry breaking
Peskin, M.E.
1982-12-01
These lectures concern the dynamics of fermions in strong interaction with gauge fields. Systems of fermions coupled by gauge forces have a very rich structure of global symmetries, which are called chiral symmetries. These lectures will focus on the realization of chiral symmetries and the causes and consequences of thier spontaneous breaking. A brief introduction to the basic formalism and concepts of chiral symmetry breaking is given, then some explicit calculations of chiral symmetry breaking in gauge theories are given, treating first parity-invariant and then chiral models. These calculations are meant to be illustrative rather than accurate; they make use of unjustified mathematical approximations which serve to make the physics more clear. Some formal constraints on chiral symmetry breaking are discussed which illuminate and extend the results of our more explicit analysis. Finally, a brief review of the phenomenological theory of chiral symmetry breaking is presented, and some applications of this theory to problems in weak-interaction physics are discussed. (WHK)
PeV scale right-handed neutrino dark matter in an S4 flavor-symmetric extra U(1) model
NASA Astrophysics Data System (ADS)
Daikoku, Yasuhiro; Okada, Hiroshi
2015-04-01
Recent observations of high-energy neutrinos in the IceCube experiment suggests the existence of superheavy dark matter beyond the PeV scale. We identify the parent particles of neutrinos as two degenerated right-handed neutrinos, assuming the dark matter is the heaviest right-handed neutrino. The O (Vc b)˜O (10-2) flavor symmetry breaking accounts for the O (10-4) mass degeneracy of right-handed neutrinos, which is a sizable scale to explain the successful resonant leptogenesis at the PeV scale. At the same time, nonthermal production of the heaviest right-handed neutrino gives the right amount of dark matter for TRH˜10 PeV . The footprint of flavor symmetry is left in the degenerated mass spectra of the extra Higgs multiplet and colored Higgs multiplet, which may be testable at the LHC or future colliders.
Safety evaluation of natural flavour complexes.
Smith, R L; Adams, T B; Cohen, S M; Doull, J; Feron, V J; Goodman, J I; Hall, R L; Marnett, L J; Portoghese, P S; Waddell, W J; Wagner, B M
2004-04-01
Natural flavour complexes (NFCs) are chemical mixtures obtained by applying physical separation methods to botanical sources. Many NFCs are derived from foods. In the present paper, a 12-step procedure for the safety evaluation of NFCs, 'the naturals paradigm', is discussed. This procedure, which is not intended to be viewed as a rigid check list, begins with a description of the chemical composition of the commercial product, followed by a review of the data on the history of dietary use. Next, each constituent of an NFC is assigned to one of 33 congeneric groups of structurally related substances and to one of three classes of toxic potential, each with its own exposure threshold of toxicological concern. The group of substances of unknown structure is placed in the class of greatest toxic potential. In subsequent steps, for each congeneric group the procedure determines the per capita intake, considers metabolic pathways and explores the need and availability of toxicological data. Additional toxicological and analytical data may be required for a comprehensive safety evaluation. The procedure concludes with an evaluation of the NFC in its entirety, also considering combined exposure to congeneric groups. The first experiences with the use of this procedure are very promising. Future safety evaluations of larger numbers of NFCs will indicate the usefulness of the system, either in its present form or in a form modified on the basis of experience.
Lepton mixing, residual symmetries, and trigonometric Diophantine equations
NASA Astrophysics Data System (ADS)
Hu, Bo
2014-10-01
In this paper, we study residual symmetries in the lepton sector. Our first concern is the symmetry of the charged lepton mass matrix in the basis where the Majorana neutrino mass matrix is diagonal, which is strongly constrained by the requirement that the symmetry group generated by residual symmetries is finite. In a recent work, R. M. Fonseca and W. Grimus found that there exists a set of constraint equations that can be completely solved, which is essential in their approach to the classification of lepton mixing matrices that are fully determined by residual symmetries. In this paper, a method to handle trigonometric Diophantine equations is introduced. We will show that the constraint equations found by Fonseca and Grimus can also be solved by this method. Detailed derivation and discussion will be presented in a self-contained way. In addition, we will also show that, in the case where residual symmetries satisfy a reality condition, this method can be used to solve the equation constraining parameters in the symmetry assignment that controls the group structure generated by residual symmetries and is directly related to mixing matrix elements.
NASA Technical Reports Server (NTRS)
Helfand, D. J.
1979-01-01
A calculation of the flux of ultra-high energy neutrinos from galactic neutron stars is presented. The calculation is used to determine the number of point sources detectable at the sensitivity threshold of a proposed deep underwater muon and neutrino detector array. The detector array would have a point source detection threshold of about 100 eV/sq cm-sec. Analysis of neutrino luminosities and the number of detectable sources suggests that the deep underwater detector may make a few discoveries. In particular, a suspected neutron star in the Cyg X-3 source seems a promising target for the deep underwater array.
Neutrinos: Nature's Identity Thieves?
Dr. Don Lincoln
2016-07-12
The oscillation of neutrinos from one variety to another has long been suspected, but was confirmed only about 15 years ago. In order for these oscillations to occur, neutrinos must have a mass, no matter how slight. Since neutrinos have long been thought to be massless, in a very real way, this phenomena is a clear signal of physics beyond the known. In this video, Fermilab's Dr Don Lincoln explains how we know it occurs and hints at the rich experimental program at several international laboratories designed to understand this complex mystery.
Neutrinos: Nature's Identity Thieves?
Dr. Don Lincoln
2013-07-11
The oscillation of neutrinos from one variety to another has long been suspected, but was confirmed only about 15 years ago. In order for these oscillations to occur, neutrinos must have a mass, no matter how slight. Since neutrinos have long been thought to be massless, in a very real way, this phenomena is a clear signal of physics beyond the known. In this video, Fermilab's Dr Don Lincoln explains how we know it occurs and hints at the rich experimental program at several international laboratories designed to understand this complex mystery.
Neutrinos: Nature's Identity Thieves?
Lincoln, Don
2014-08-07
The oscillation of neutrinos from one variety to another has long been suspected, but was confirmed only about 15 years ago. In order for these oscillations to occur, neutrinos must have a mass, no matter how slight. Since neutrinos have long been thought to be massless, in a very real way, this phenomena is a clear signal of physics beyond the known. In this video, Fermilab's Dr Don Lincoln explains how we know it occurs and hints at the rich experimental program at several international laboratories designed to understand this complex mystery.
Implications of μ- τ flavored CP symmetry of leptons
NASA Astrophysics Data System (ADS)
Mohapatra, R. N.; Nishi, C. C.
2015-08-01
We discuss gauge models incorporating μ-τ flavored CP symmetry (called CP μτ in the text) in combination with L μ - L τ invariance to understand neutrino mixings and discuss their phenomenological implications. We show that viable leptogenesis in this setting requires that the lightest right-handed neutrino mass must be between 109-1012 GeV and for effective two hierarchical right-handed neutrinos, leptogenesis takes place only in a narrower range of 5 × 1010-1012 GeV. A multi-Higgs realization of this idea implies that there must be a pseudoscalar Higgs boson with mass less than 300 GeV. Generically, the vev alignment problem can be naturally avoided in our setting.
Yeo, Lihe; Thompson, Donald B; Peterson, Devin G
2016-05-15
This study investigated how hydrophobicity, solubility and the concentration of flavour compounds related to inclusion complexation by dispersed native high amylose maize starch (HAMS). The effect of native lipid on flavour retention and the effect of time (one day to one month) on flavour retention and precipitated starch yield was also examined. Flavour-starch complexation was dependent on the flavour compound hydrophobicity, the flavour concentration in a dose-dependent manner and also influenced by time (increased during storage). Flavour composition also influenced starch complexation; no flavour complexes were reported with limonene by itself but were observed when added in binary flavour mixtures with menthone or thymol. Furthermore, no difference in flavour retention was observed for native and lipid-free starch dispersions. In summary, flavour inclusion complexes with HAMS exhibited cooperativity-type binding behaviour; with a critical ligand concentration needed for a stable physical association between flavour compounds and HAMS.
A non-standard CP transformation leading to maximal atmospheric neutrino mixing
NASA Astrophysics Data System (ADS)
Grimus, Walter; Lavoura, Luís.
2004-01-01
We discuss a neutrino mass matrix Mν originally found by Babu, Ma, and Valle (BMV) and show that this mass matrix can be characterized by a simple algebraic relation. From this relation it follows that atmospheric neutrino mixing is exactly maximal while at the same time an arbitrary mixing angle θ13 of the lepton mixing matrix U is allowed and—in the usual phase convention—CP violation in mixing is maximal; moreover, neither the neutrino mass spectrum nor the solar mixing angle are restricted. We put forward a seesaw extension of the Standard Model, with three right-handed neutrinos and three Higgs doublets, where the family lepton numbers are softly broken by the Majorana mass terms of the right-handed neutrino singlets and the BMV mass matrix results from a non-standard CP symmetry.
Hidden gauged U (1 ) model: Unifying scotogenic neutrino and flavor dark matter
NASA Astrophysics Data System (ADS)
Yu, Jiang-Hao
2016-06-01
In both scotogenic neutrino and flavor dark matter models, the dark sector communicates with the standard model fermions via Yukawa portal couplings. We propose an economic scenario where the scotogenic neutrino and a flavored mediator share the same inert Higgs doublet and all are charged under a hidden gauged U (1 ) symmetry. The dark Z2 symmetry in the dark sector is regarded as the remnant of this hidden U (1 ) symmetry breaking. In particular, we investigate a dark U (1 )D [and also U (1 )B-L] model which unifies the scotogenic neutrino and top-flavored mediator. Thus dark tops and dark neutrinos are the standard model fermion partners, and the dark matter could be the inert Higgs or the lightest dark neutrino. We note that this model has rich collider signatures on dark tops, the inert Higgs and the Z' gauge boson. Moreover, the scalar associated to the U (1 )D [and also U (1 )B -L ] symmetry breaking could explain the 750 GeV diphoton excess reported by ATLAS and CMS recently.
NASA Astrophysics Data System (ADS)
Volpe, Cristina; Baha Balantekin, A.
2014-04-01
Understanding the origin of the elements around us is one of the main quests of modern science. Realizing that only a few of the lightest elements can have been produced in the early Universe because of the lack of stable nuclei with A = 5 and A = 8, and that stars need to be producing some of the heavier nuclei up to iron so they may shine were triumphs of nuclear physics in the first part of the 20th century. For the synthesis of heavier elements the situation is more complicated. In particular, the site of r-process nucleosynthesis is still an open question. Suggested sites for r-process nucleosynthesis include the high-temperature, high-entropy region outside the newly formed neutron star in a core-collapse supernova, 4He mantles of the metal-poor (i.e. early) supernova progenitors, neutron-star mergers and accretion discs around black holes. The nucleosynthetic outcomes in such sites depend on their neutron- or proton-richness, which is determined by the astrophysical conditions as well as the properties of exotic nuclei, far from the valley of stability. A key development during the last few decades has been the appreciation of the close relationship between neutrinos and nucleosynthesis as physicists and astronomers ascertained the fact that neutrino properties figure prominently in many astrophysical environments. Neutrinos are involved in different types of stellar nucleosynthesis processes: the v-process, the v p process and the r-process. These developments have occurred in parallel with the impressive progress in our understanding of neutrino masses and mixings as well as neutrino flavour conversion in astrophysical (and cosmological) environments. Neutrino interactions with protons and neutrons impact the conditions for proton or neutron richness of a given site. Further investigations are necessary in order to fully unravel neutrino flavour conversion phenomena in these environments and to establish how much these finally impact the nucleosynthesis
Gauge U(1) dark symmetry and radiative light fermion masses
NASA Astrophysics Data System (ADS)
Kownacki, Corey; Ma, Ernest
2016-09-01
A gauge U (1) family symmetry is proposed, spanning the quarks and leptons as well as particles of the dark sector. The breaking of U (1) to Z2 divides the two sectors and generates one-loop radiative masses for the first two families of quarks and leptons, as well as all three neutrinos. We study the phenomenological implications of this new connection between family symmetry and dark matter. In particular, a scalar or pseudoscalar particle associated with this U (1) breaking may be identified with the 750 GeV diphoton resonance recently observed at the Large Hadron Collider (LHC).
Predictions for the Dirac CP violation phase in the neutrino mixing matrix
NASA Astrophysics Data System (ADS)
Petcov, S. T.; Girardi, I.; Titov, A. V.
2015-05-01
Using the fact that the neutrino mixing matrix U = UeUν , where Ue and Uν result from the diagonalization of the charged lepton and neutrino mass matrices, we analyze the predictions based on the sum rules which the Dirac phase δ present in U satisfies when Uν has a form dictated by, or associated with, discrete flavor symmetries and Ue has a "minimal" form (in terms of angles and phases it contains) that can provide the requisite corrections to Uν, so that the reactor, atmospheric and solar neutrino mixing angles θ13, θ23 and θ12 have values compatible with the current data.
Predictions for the Dirac CP Violation Phase in the Neutrino Mixing Matrix
NASA Astrophysics Data System (ADS)
Petcov, S. T.; Girardi, I.; Titov, A. V.
Using the fact that the neutrino mixing matrix U = U_{e}^{dagger} U_{ν}, where Ue and Uν result from the diagonalization of the charged lepton and neutrino mass matrices, we analyze the predictions based on the sum rules which the Dirac phase δ present in U satisfies when Uν has a form dictated by, or associated with, discrete favor symmetries and Ue has a "minimal" form (in terms of angles and phases it contains) that can provide the requisite corrections to Uν, so that the reactor, atmospheric and solar neutrino mixing angles θ13, θ23 and θ12 have values compatible with the current data.
Neutrino Signal of Electron-Capture Supernovae from Core Collapse to Cooling
Huedepohl, L.; Mueller, B.; Janka, H.-T.; Marek, A.; Raffelt, G. G.
2010-06-25
An 8.8M{sub {center_dot}}electron-capture supernova was simulated in spherical symmetry consistently from collapse through explosion to essentially complete deleptonization of the forming neutron star. The evolution time ({approx}9 s) is short because high-density effects suppress our neutrino opacities. After a short phase of accretion-enhanced luminosities ({approx}200 ms), luminosity equipartition among all species becomes almost perfect and the spectra of {nu}{sub e} and {nu}{sub {mu},{tau}}very similar, ruling out the neutrino-driven wind as r-process site. We also discuss consequences for neutrino flavor oscillations.
Neutrino signal of electron-capture supernovae from core collapse to cooling.
Hüdepohl, L; Müller, B; Janka, H-T; Marek, A; Raffelt, G G
2010-06-25
An 8.8M{⊙} electron-capture supernova was simulated in spherical symmetry consistently from collapse through explosion to essentially complete deleptonization of the forming neutron star. The evolution time (∼9 s) is short because high-density effects suppress our neutrino opacities. After a short phase of accretion-enhanced luminosities (∼200 ms), luminosity equipartition among all species becomes almost perfect and the spectra of ν{e} and ν{μ,τ} very similar, ruling out the neutrino-driven wind as r-process site. We also discuss consequences for neutrino flavor oscillations.
Simple mass matrices of neutrinos and quarks consistent with observed mixings and masses
NASA Astrophysics Data System (ADS)
Nishiura, Hiroyuki; Fukuyama, Takeshi
2016-02-01
We propose a simple phenomenological model of quarks-leptons mass matrices having fundamentally universal symmetry structure. These mass matrices consist of democratic and semi-democratic mass matrix terms commonly to the neutrino and the quark sectors and have only eight free parameters. We show that this mass matrix model well reproduces all the observed values of the MNS lepton and the CKM quark mixing angles, the neutrino mass squared difference ratio, and quark mass ratios, with an excellent agreement. The model also predicts δCPℓ = - 94 ° for the leptonic CP violating phase and < m > ≃ 0.0073 eV for the effective Majorana neutrino mass.
A new B - L model without right-handed neutrinos
NASA Astrophysics Data System (ADS)
Patra, Sudhanwa; Rodejohann, Werner; Yaguna, Carlos E.
2016-09-01
We propose and study a novel extension of the Standard Model based on the B- L gauge symmetry that can account for dark matter and neutrino masses. In this model, right-handed neutrinos are absent and the gauge anomalies are canceled instead by four chiral fermions with fractional B - L charges. After the breaking of U(1) B- L , these fermions arrange themselves into two Dirac particles, the lightest of which is automatically stable and plays the role of the dark matter. We determine the regions of the parameter space consistent with the observed dark matter density and show that they can be partially probed via direct and indirect dark matter detection or collider searches at the LHC. Neutrino masses, on the other hand, can be explained by a variant of the type-II seesaw mechanism involving one of the two scalar fields responsible for the dark matter mass.
Consequences of an Abelian Z' for neutrino oscillations and dark matter
NASA Astrophysics Data System (ADS)
Plestid, Ryan
2016-02-01
The Standard Model's accidental and anomaly-free currents, B -L , Le-Lμ, Le-Lτ, and Lμ-Lτ, could be indicative of a hidden gauge structure beyond the Standard Model. Additionally, neutrino masses can be generated by a dimension-5 operator that generically breaks all of these symmetries. It is therefore important to investigate the compatibility of a gauged U'(1 ) and neutrino phenomenology. We consider gauging each of the symmetries above with a minimal extended matter content. This includes the Z', an order parameter to break the U'(1 ), and three right-handed neutrinos. We find all but B -L require additional matter content to explain the measured neutrino oscillation parameters. We also discuss the compatibility of the measured neutrino textures with a nonthermal dark matter production mechanism involving the decay of the Z'. Finally, we present a parametric relation that implies that any sterile neutrino dark matter candidate should not be expected to contribute to neutrino masses beyond ten parts per million.
Spectrum and Decays of S-wave tetraquarks from chromomagnetism with flavour symmetry breaking
Buccella, Franco
2008-08-31
From a necessary condition for 'open door' decays of tetraquarks into two pseudoscalar mesons or into a vector and pseudoscalar mesons, we deduce that the lighter states may have strong couplings into these final states.
NASA Astrophysics Data System (ADS)
Arns, Robert G.
In 1930 Wolfgang Pauli suggested that a new particle might be required to make sense of the radioactive-disintegration mode known as beta decay. This conjecture initially seemed impossible to verify since the new particle, which became known as the neutrino, was uncharged, had zero or small mass, and interacted only insignificantly with other matter. In 1951 Frederick Reines and Clyde L. Cowan, Jr., of the Los Alamos Scientific Laboratory undertook the difficult task of detecting the free neutrino by observing its inverse beta-decay interaction with matter. They succeeded in 1956. The neutrino was accepted rapidly as a fundamental particle despite discrepancies in reported details of the experiments and despite the absence of independent verification of the result. This paper describes the experiments, examines the nature of the discrepancies, and discusses the circumstances of the acceptance of the neutrino's detection by the physics community.
NASA Astrophysics Data System (ADS)
Gariazzo, S.; Giunti, C.; Laveder, M.; Li, Y. F.; Zavanin, E. M.
2015-03-01
The theory and phenomenology of light sterile neutrinos at the eV mass scale is reviewed. The reactor, gallium and Liquid Scintillator Neutrino Detector anomalies are briefly described and interpreted as indications of the existence of short-baseline oscillations which require the existence of light sterile neutrinos. The global fits of short-baseline oscillation data in 3 + 1 and 3 + 2 schemes are discussed, together with the implications for β-decay and neutrinoless double-β decay. The cosmological effects of light sterile neutrinos are briefly reviewed and the implications of existing cosmological data are discussed. The review concludes with a summary of future perspectives. This review is dedicated to the memory of Hai-Wei Long, our dear friend and collaborator, who passed away on 29 May 2015. He was an exceptionally kind person and an enthusiastic physicist. We deeply miss him.
NASA Astrophysics Data System (ADS)
Gariazzo, S.; Giunti, C.; Laveder, M.; Li, Y. F.; Zavanin, E. M.
2016-03-01
The theory and phenomenology of light sterile neutrinos at the eV mass scale is reviewed. The reactor, gallium and Liquid Scintillator Neutrino Detector anomalies are briefly described and interpreted as indications of the existence of short-baseline oscillations which require the existence of light sterile neutrinos. The global fits of short-baseline oscillation data in 3 + 1 and 3 + 2 schemes are discussed, together with the implications for β-decay and neutrinoless double-β decay. The cosmological effects of light sterile neutrinos are briefly reviewed and the implications of existing cosmological data are discussed. The review concludes with a summary of future perspectives. This review is dedicated to the memory of Hai-Wei Long, our dear friend and collaborator, who passed away on 29 May 2015. He was an exceptionally kind person and an enthusiastic physicist. We deeply miss him.
NASA Astrophysics Data System (ADS)
Long, K.
2015-07-01
In the summer of 2013 the International Committee on Future Accelerators (ICFA) established a Neutrino Panel with the mandate: "To promote international cooperation in the development of the accelerator-based neutrino-oscillation program and to promote international collaboration in the development of a neutrino factory as a future intense source of neutrinos for particle physics experiments." In its first year the Panel organised a series of regional Town Meetings to collect input from the community and to receive reports from the regional planning exercises. The Panel distilled its findings and presented them in a report to ICFA [1]. In this contribution the formation and composition of the Panel are presented together with a summary of the Panel's findings from the three Regional Town Meetings. The Panel's initial conclusions are then articulated and the steps that the Panel seeks to take are outlined.
Long, K.
2015-07-15
In the summer of 2013 the International Committee on Future Accelerators (ICFA) established a Neutrino Panel with the mandate: <<
Ultrahigh energy neutrino interactions
NASA Astrophysics Data System (ADS)
Domokos, G.; Elliot, B.; Kovesi-Domokos, S.; Mrenna, S.
1990-03-01
Ultrahigh energy neutrinos are valuable probes of physics beyond the Standard Model. Neutrinos of the highest energies are emitted by point sources in the sky. We review briefly the predictions of the Standard Model concerning neutrino interactions. We further argue that a number of preon models designed to overcome some difficulties of the Standard Model leads to a blurring of the distinction between leptons and quarks. As a consequence, at sufficiently high energies neutrinos acquire ``anomalous'' interactions. While this phenomenon can probably explain the observed muon excess in extensive air showers (EAS), it can be also tested by studying the absorption of the primaries on the cosmic microwave background. We discuss some observations to be performed in the search of such ``new physics'' beyond the Standard Model.
Pierce, Aaron; Murayama, Hitoshi
2003-10-28
Recent data from the Wilkinson Microwave Anisotropy Probe (WMAP) place important bounds on the neutrino sector. The precise determination of the baryon number in the universe puts a strong constraint on the number of relativistic species during Big-Bang Nucleosynthesis. WMAP data, when combined with the 2dF Galaxy Redshift Survey (2dFGRS), also directly constrain the absolute mass scale of neutrinos. These results impinge upon a neutrino oscillation interpretation of the result from the Liquid Scintillator Neutrino Detector (LSND).We also note that the Heidelberg-Moscow evidence for neutrinoless double beta decay is only consistent with the WMAP+2dFGRS data for the largest values of the nuclear matrix element.
The Sudbury Neutrino Observatory
NASA Astrophysics Data System (ADS)
Ewan, G. T.
1992-04-01
The Sudbury Neutrino Observatory (SNO) detector is a 1000 ton heavy water (D2O) Cherenkov detector designed to study neutrinos from the sun and other astrophysical sources. The use of heavy water allows both electron neutrinos and all other types of neutrinos to be observed by three complementary reactions. The detector will be sensitive to the electron neutrino flux and energy spectrum shape and to the total neutrino flux irrespective of neutrino type. These measurements will provide information on both vacuum neutrino oscillations and matter-enhanced oscillations, the MSW effect. In the event of a supernova it will be very sensitive to muon and tau neutrinos as well as the electron neutrinos emitted in the initial burst, enabling sensitive mass measurements as well as providing details of the physics of stellar collapse. On behalf of the Sudbury Neutrino Observatory (SNO) Collaboration : H.C . Evans, G.T . Ewan, H.W. Lee, J .R . Leslie, J .D. MacArthur, H .-B . Mak, A.B . McDonald, W. McLatchie, B.C . Robertson, B. Sur, P. Skensved (Queen's University) ; C.K . Hargrove, H. Mes, W.F. Davidson, D. Sinclair, 1 . Blevis, M. Shatkay (Centre for Research in Particle Physics) ; E.D. Earle, G.M. Milton, E. Bonvin, (Chalk River Laboratories); J .J . Simpson, P. Jagam, J . Law, J .-X . Wang (University of Guelph); E.D . Hallman, R.U. Haq (Laurentian University); A.L. Carter, D. Kessler, B.R . Hollebone (Carleton University); R. Schubank . C.E . Waltha m (University of British Columbia); R.T. Kouzes, M.M. Lowry, R.M. Key (Princeton University); E.W. Beier, W. Frati, M. Newcomer, R. Van Berg (University of Penn-sylvania), T.J . Bowles, P.J . Doe, S.R . Elliott, M.M. Fowler, R.G.H. Robertson, D.J . Vieira, J .B . Wilhelmy, J .F. Wilker-son, J .M. Wouters (Los Alamos National Laboratory) ; E. Norman, K. Lesko, A. Smith, R. Fulton, R. Stokstad (Lawrence Berkeley Laboratory), N.W. Tanner, N. JCIILY, P. Trent, J . Barton, D.L . Wark (University of Oxford).
Effective Majorana neutrino decay
NASA Astrophysics Data System (ADS)
Duarte, Lucía; Romero, Ismael; Peressutti, Javier; Sampayo, Oscar A.
2016-08-01
We study the decay of heavy sterile Majorana neutrinos according to the interactions obtained from an effective general theory. We describe the two- and three-body decays for a wide range of neutrino masses. The results obtained and presented in this work could be useful for the study of the production and detection of these particles in a variety of high energy physics experiments and astrophysical observations. We show in different figures the dominant branching ratios and the total decay width.
Cosmological and supernova neutrinos
NASA Astrophysics Data System (ADS)
Kajino, T.; Aoki, W.; Balantekin, A. B.; Cheoun, M.-K.; Hayakawa, T.; Hidaka, J.; Hirai, Y.; Kusakabe, M.; Mathews, G. J.; Nakamura, K.; Pehlivan, Y.; Shibagaki, S.; Suzuki, T.
2014-06-01
The Big Bang nucleosynthesis (BBN) and the cosmic microwave background (CMB) anisotropies are the pillars of modern cosmology. It has recently been suggested that axion which is a dark matter candidate in the framework of the standard model could condensate in the early universe and induce photon cooling before the epoch of the photon last scattering. Although this may render a solution to the overproduction problem of primordial 7Li abundance, there arises another serious difficulty of overproducing D abundance. We propose a hybrid dark matter model with both axions and relic supersymmetric (SUSY) particles to solve both overproduction problems of the primordial D and 7Li abundances simultaneously. The BBN also serves to constrain the nature of neutrinos. Considering non-thermal photons produced in the decay of the heavy sterile neutrinos due to the magnetic moment, we explore the cosmological constraint on the strength of neutrino magnetic moment consistent with the observed light element abundances. Core-collapse supernovae eject huge flux of energetic neutrinos which affect explosive nucleosynthesis of rare isotopes like 7Li, 11B, 92Nb, 138La and 180Ta and r-process elements. Several isotopes depend strongly on the neutrino flavor oscillation due to the Mikheyev-Smirnov-Wolfenstein (MSW) effect. Combining the recent experimental constraints on θ13 with predicted and observed supernova-produced abundance ratio 11B/7Li encapsulated in the presolar grains from the Murchison meteorite, we show a marginal preference for an inverted neutrino mass hierarchy. We also discuss supernova relic neutrinos (SRN) that may indicate the softness of the equation of state (EoS) of nuclear matter and adiabatic conditions of the neutrino oscillation.
Neutrinos from GRBs cannonballs
NASA Astrophysics Data System (ADS)
Hubbard, J. R.; Ferry, S.
We present a new estimation of the production of prompt neutrinos in the Cannonball Model of Gamma Ray Bursts proposed by Dar and De Rújula. Interactions between nucleons in the cannonballs and nucleons in the supernova shell are calculated in the rest frame of the shocked matter produced by these interactions. We explore the neutrino yield as a function of the parameters of the model.
Cosmological and supernova neutrinos
Kajino, T.; Aoki, W.; Balantekin, A. B.; Cheoun, M.-K.; Hayakawa, T.; Hidaka, J.; Hirai, Y.; Shibagaki, S.; Kusakabe, M.; Mathews, G. J.; Nakamura, K.; Pehlivan, Y.; Suzuki, T.
2014-06-24
The Big Bang nucleosynthesis (BBN) and the cosmic microwave background (CMB) anisotropies are the pillars of modern cosmology. It has recently been suggested that axion which is a dark matter candidate in the framework of the standard model could condensate in the early universe and induce photon cooling before the epoch of the photon last scattering. Although this may render a solution to the overproduction problem of primordial {sup 7}Li abundance, there arises another serious difficulty of overproducing D abundance. We propose a hybrid dark matter model with both axions and relic supersymmetric (SUSY) particles to solve both overproduction problems of the primordial D and {sup 7}Li abundances simultaneously. The BBN also serves to constrain the nature of neutrinos. Considering non-thermal photons produced in the decay of the heavy sterile neutrinos due to the magnetic moment, we explore the cosmological constraint on the strength of neutrino magnetic moment consistent with the observed light element abundances. Core-collapse supernovae eject huge flux of energetic neutrinos which affect explosive nucleosynthesis of rare isotopes like {sup 7}Li, {sup 11}B, {sup 92}Nb, {sup 138}La and {sup 180}Ta and r-process elements. Several isotopes depend strongly on the neutrino flavor oscillation due to the Mikheyev-Smirnov-Wolfenstein (MSW) effect. Combining the recent experimental constraints on θ{sub 13} with predicted and observed supernova-produced abundance ratio {sup 11}B/{sup 7}Li encapsulated in the presolar grains from the Murchison meteorite, we show a marginal preference for an inverted neutrino mass hierarchy. We also discuss supernova relic neutrinos (SRN) that may indicate the softness of the equation of state (EoS) of nuclear matter and adiabatic conditions of the neutrino oscillation.
Diet, sensitive periods in flavour learning, and growth
TRABULSI, JILLIAN C.; MENNELLA, JULIE A.
2015-01-01
Diet in early infancy has an impact on early growth and the formation of flavour preferences, as well as on later life health outcomes. Although breast milk is the preferred source of nutrition during infancy, more than half of American infants receive infant formula by the age of 4 months. As a group, formula-fed infants weigh more by the age of one year and have a greater risk for later obesity than breastfed infants. However, a recent randomized study found that, when compared to breastfed infants, infants fed an extensively hydrolysed protein formula (ePHF) had more normative weight gain velocity than infants fed cow’s milk formula (CMF). Therefore, grouping all formula-fed infants together with respect to certain health outcomes such as obesity may not be appropriate. Scientific evidence also suggests that there are sensitive periods for flavour learning. Infants become familiar with and learn to accept the flavours they experience through their mother’s amniotic fluid and breast milk as well as formula. These early experiences influence flavour preferences of children that may affect food choices and therefore later life health. Further research on the influence of early diet on growth, flavour preferences, and food choices is imperative. PMID:22724643
Biovanillin from agro wastes as an alternative food flavour.
Zamzuri, Nur Ain; Abd-Aziz, Suraini
2013-02-01
This review provides an overview of biovanillin production from agro wastes as an alternative food flavour. Biovanillin is one of the widely used flavour compounds in the foods, beverages and pharmaceutical industries. An alternative production approach for biovanillin as a food flavour is hoped for due to the high and variable cost of natural vanillin as well as the limited availability of vanilla pods in the market. Natural vanillin refers to the main organic compound that is extracted from the vanilla bean, as compared to biovanillin, which is produced biologically by microorganisms from a natural precursor such as ferulic acid. Biovanillin is also reviewed as a potential bioflavour produced by microbial fermentation in an economically feasible way in the near future. In fact, we briefly discuss natural, synthetic and biovanillin and the types of agro wastes that are useful as sources for bioconversion of ferulic acid into biovanillin. The subsequent part of the review emphasizes the current application of vanillin as well as the utilization of biovanillin as an alternative food flavour. The final part summarizes biovanillin production from agro wastes that could be of benefit as a food flavour derived from potential natural precursors.
Mixed symmetry tensors in the worldline formalism
NASA Astrophysics Data System (ADS)
Corradini, Olindo; Edwards, James P.
2016-05-01
We consider the first quantised approach to quantum field theory coupled to a non-Abelian gauge field. Representing the colour degrees of freedom with a single family of auxiliary variables the matter field transforms in a reducible representation of the gauge group which — by adding a suitable Chern-Simons term to the particle action — can be projected onto a chosen fully (anti-)symmetric representation. By considering F families of auxiliary variables, we describe how to extend the model to arbitrary tensor products of F reducible representations, which realises a U( F ) "flavour" symmetry on the world-line particle model. Gauging this symmetry allows the introduction of constraints on the Hilbert space of the colour fields which can be used to project onto an arbitrary irreducible representation, specified by a certain Young tableau. In particular the occupation numbers of the wavefunction — i.e. the lengths of the columns (rows) of the Young tableau — are fixed through the introduction of Chern-Simons terms. We verify this projection by calculating the number of colour degrees of freedom associated to the matter field. We suggest that, using the worldline approach to quantum field theory, this mechanism will allow the calculation of one-loop scattering amplitudes with the virtual particle in an arbitrary representation of the gauge group.
Rare Isotopes and Fundamental Symmetries
NASA Astrophysics Data System (ADS)
Brown, B. Alex; Engel, Jonathan; Haxton, Wick; Ramsey-Musolf, Michael; Romalis, Michael; Savard, Guy
2009-01-01
Experiments searching for new interactions in nuclear beta decay / Klaus P. Jungmann -- The beta-neutrino correlation in sodium-21 and other nuclei / P. A. Vetter ... [et al.] -- Nuclear structure and fundamental symmetries/ B. Alex Brown -- Schiff moments and nuclear structure / J. Engel -- Superallowed nuclear beta decay: recent results and their impact on V[symbol] / J. C. Hardy and I. S. Towner -- New calculation of the isospin-symmetry breaking correlation to superallowed Fermi beta decay / I. S. Towner and J. C. Hardy -- Precise measurement of the [symbol]H to [symbol]He mass difference / D. E. Pinegar ... [et al.] -- Limits on scalar currents from the 0+ to 0+ decay of [symbol]Ar and isospin breaking in [symbol]Cl and [symbol]Cl / A. Garcia -- Nuclear constraints on the weak nucleon-nucleon interaction / W. C. Haxton -- Atomic PNC theory: current status and future prospects / M. S. Safronova -- Parity-violating nucleon-nucleon interactions: what can we learn from nuclear anapole moments? / B. Desplanques -- Proposed experiment for the measurement of the anapole moment in francium / A. Perez Galvan ... [et al.] -- The Radon-EDM experiment / Tim Chupp for the Radon-EDM collaboration -- The lead radius Eexperiment (PREX) and parity violating measurements of neutron densities / C. J. Horowitz -- Nuclear structure aspects of Schiff moment and search for collective enhancements / Naftali Auerbach and Vladimir Zelevinsky -- The interpretation of atomic electric dipole moments: Schiff theorem and its corrections / C. -P. Liu -- T-violation and the search for a permanent electric dipole moment of the mercury atom / M. D. Swallows ... [et al.] -- The new concept for FRIB and its potential for fundamental interactions studies / Guy Savard -- Collinear laser spectroscopy and polarized exotic nuclei at NSCL / K. Minamisono -- Environmental dependence of masses and coupling constants / M. Pospelov.
Flavor symmetries and fermion masses
Rasin, A.
1994-04-01
We introduce several ways in which approximate flavor symmetries act on fermions and which are consistent with observed fermion masses and mixings. Flavor changing interactions mediated by new scalars appear as a consequence of approximate flavor symmetries. We discuss the experimental limits on masses of the new scalars, and show that the masses can easily be of the order of weak scale. Some implications for neutrino physics are also discussed. Such flavor changing interactions would easily erase any primordial baryon asymmetry. We show that this situation can be saved by simply adding a new charged particle with its own asymmetry. The neutrality of the Universe, together with sphaleron processes, then ensures a survival of baryon asymmetry. Several topics on flavor structure of the supersymmetric grand unified theories are discussed. First, we show that the successful predictions for the Kobayashi-Maskawa mixing matrix elements, V{sub ub}/V{sub cb} = {radical}m{sub u}/m{sub c} and V{sub td}/V{sub ts} = {radical}m{sub d}/m{sub s}, are a consequence of a large class of models, rather than specific properties of a few models. Second, we discuss how the recent observation of the decay {beta} {yields} s{gamma} constrains the parameter space when the ratio of the vacuum expectation values of the two Higgs doublets, tan{Beta}, is large. Finally, we discuss the flavor structure of proton decay. We observe a surprising enhancement of the branching ratio for the muon mode in SO(10) models compared to the same mode in the SU(5) model.
Gravitino Dark Matter, Neutrino Masses and Lepton Flavor Violation from broken R-parity
Lola, S.
2009-04-17
We study gravitino dark matter and slow gravitino decays in supersymmetric theories with broken R-parity. It turns out that for the model parameters that may give rise to viable radiative neutrino masses, and visible R-violating signatures in colliders, gravitinos are cosmologically stable and can be good dark matter candidates. On the contrary, the decays of the Next-to-Lightest Supersymmetric Particle are fast, and can be easily reconciled with Big Bang Nucleosynthesis. For the interesting range of parameters, observable lepton flavour violation is also to be expected, with rates that are strongly dependent from the flavour structure of the R-violating operators, and with distinct correlations that should be distinguishable in the coming generation of experiments.
Neutrino experiments: Hierarchy, CP, CPT
NASA Astrophysics Data System (ADS)
Gupta, Manmohan; Randhawa, Monika; Singh, Mandip
2016-07-01
We present an overview of our recent investigations regarding the prospects of ongoing neutrino experiments as well as future experiments in determining few of the most important unknowns in the field of neutrino physics, specifically the neutrino mass ordering and leptonic CP-violation phase. The effect of matter oscillations on the neutrino oscillation probabilities has been exploited in resolving the degeneracy between the neutrino mass ordering and the CP violation phase in the leptonic sector. Further, we estimate the extent of extrinsic CP and CPT violation in the experiments with superbeams as well as neutrino factories.
Neutrino Detectors: Challenges and Opportunities
Soler, F. J. P.
2011-10-06
This paper covers possible detector options suitable at future neutrino facilities, such as Neutrino Factories, Super Beams and Beta Beams. The Magnetised Iron Neutrino Detector (MIND), which is the baseline detector at a Neutrino Factory, will be described and a new analysis which improves the efficiency of this detector at low energies will be shown. Other detectors covered include the Totally Active Scintillating Detectors (TASD), particularly relevant for a low energy Neutrino Factory, emulsion detectors for tau detection, liquid argon detectors and megaton scale water Cherenkov detectors. Finally the requirements of near detectors for long-baseline neutrino experiments will be demonstrated.
Electromagnetic properties of massive neutrinos
Dobrynina, A. A. Mikheev, N. V.; Narynskaya, E. N.
2013-10-15
The vertex function for a virtual massive neutrino is calculated in the limit of soft real photons. A method based on employing the neutrino self-energy operator in a weak external electromagnetic field in the approximation linear in the field is developed in order to render this calculation of the vertex function convenient. It is shown that the electric charge and the electric dipole moment of the real neutrino are zero; only the magnetic moment is nonzero for massive neutrinos. A fourth-generation heavy neutrino of mass not less than half of the Z-boson mass is considered as a massive neutrino.
Neutrinos beyond the Standard Model
Valle, J.W.F.
1989-08-01
I review some basic aspects of neutrino physics beyond the Standard Model such as neutrino mixing and neutrino non-orthogonality, universality and CP violation in the lepton sector, total lepton number and lepton flavor violation, etc.. These may lead to neutrino decays and oscillations, exotic weak decay processes, neutrinoless double /beta/ decay, etc.. Particle physics models are discussed where some of these processes can be sizable even in the absence of measurable neutrino masses. These may also substantially affect the propagation properties of solar and astrophysical neutrinos. 39 refs., 4 figs.
Nonthermal cosmic neutrino background
NASA Astrophysics Data System (ADS)
Chen, Mu-Chun; Ratz, Michael; Trautner, Andreas
2015-12-01
We point out that, for Dirac neutrinos, in addition to the standard thermal cosmic neutrino background (C ν B ), there could also exist a nonthermal neutrino background with comparable number density. As the right-handed components are essentially decoupled from the thermal bath of standard model particles, relic neutrinos with a nonthermal distribution may exist until today. The relic density of the nonthermal (nt) background can be constrained by the usual observational bounds on the effective number of massless degrees of freedom Neff and can be as large as nν nt≲0.5 nγ. In particular, Neff can be larger than 3.046 in the absence of any exotic states. Nonthermal relic neutrinos constitute an irreducible contribution to the detection of the C ν B and, hence, may be discovered by future experiments such as PTOLEMY. We also present a scenario of chaotic inflation in which a nonthermal background can naturally be generated by inflationary preheating. The nonthermal relic neutrinos, thus, may constitute a novel window into the very early Universe.
One vanishing minor in the neutrino mass matrix
Lashin, E. I.; Chamoun, N.
2009-11-01
We study a specific texture of the neutrino mass matrix, namely the models with one 2x2 subdeterminant equal to zero. We carry out a complete phenomenological analysis with all possible relevant correlations. Every pattern of the six possible ones is found able to accommodate the experimental data, with three cases allowing also for noninvertible mass matrices. We present symmetry realizations for all the models.
Predictive discrete dark matter model and neutrino oscillations
NASA Astrophysics Data System (ADS)
Boucenna, M. S.; Morisi, S.; Peinado, E.; Valle, J. W. F.; Shimizu, Yusuke
2012-10-01
Dark matter stability can be achieved through a partial breaking of a flavor symmetry. In this framework we propose a type-II seesaw model where left-handed matter transforms nontrivially under the flavor group Δ(54), providing correlations between neutrino oscillation parameters, consistent with the recent Daya-Bay and RENO reactor angle measurements, as well as lower bounds for neutrinoless double beta decay. The dark matter phenomenology is provided by a Higgs-portal.
Froggatt-Nielsen models with a residual Z4R symmetry
NASA Astrophysics Data System (ADS)
Dreiner, Herbi K.; Opferkuch, Toby; Luhn, Christoph
2013-12-01
The Froggatt-Nielsen mechanism provides an elegant explanation for the hierarchies of fermion masses and mixings in terms of a U(1) symmetry. Promoting such a family symmetry to an R symmetry, we explicitly construct supersymmetric Froggatt-Nielsen models which are gauged, family-dependent U(1)R completions of the Z4R symmetry proposed by Lee, Raby, Ratz, Ross, Schieren, Schmidt-Hoberg and Vaudrevange in 2010. Forbidden by Z4R, the μ term is generated around the supersymmetry breaking scale m3/2 from either the Kähler potential or the superpotential. Neutrinos acquire their mass via the type-I seesaw mechanism with three right-handed neutrino superfields. Taking into account the Green-Schwarz anomaly cancellation conditions, we arrive at a total of 3×34 distinct phenomenologically viable charge assignments for the standard model fields, most of which feature highly fractional charges.
Trapped ionic simulation of neutrino electromagnetic properties in neutrino oscillation
NASA Astrophysics Data System (ADS)
Wang, Z. S.; Cai, Xiaoya; Pan, Hui
2015-11-01
We present an approach to study neutrino electromagnetic properties by simulating neutrino oscillation in both dense background matter and external electromagnetic field in terms of trapped coupling ions. We find that the neutrino and anti-neutrino productions can be simulated by using large enough diagonal matter potentials and external magnetic field. We further show that the transition probabilities of flavor neutrino have rich features and time scales corresponding to the neutrino magnetic moments and electric millicharges. Especially, such features and scales can be achieved by tuning the laser parameters. At last, we show that the millicharge and magnetic moments can be detected in terms of flavor neutrino transition probabilities in the trapped ion system. Our approach provides a useful clue to measure the neutrino electromagnetic properties for experimental realization.
Signatures of top flavour-changing dark matter
NASA Astrophysics Data System (ADS)
D'Hondt, Jorgen; Mariotti, Alberto; Mawatari, Kentarou; Moortgat, Seth; Tziveloglou, Pantelis; Van Onsem, Gerrit
2016-03-01
We develop the phenomenology of scenarios in which a dark matter candidate interacts with a top quark through flavour-changing couplings, employing a simplified dark matter model with an s-channel vector-like mediator. We study in detail the top-charm flavour-changing interaction, by investigating the single top plus large missing energy signature at the LHC as well as constraints from the relic density and direct and indirect dark matter detection experiments. We present strategies to distinguish between the top-charm and top-up flavour-changing models by taking advantage of the lepton charge asymmetry as well as by using charm-tagging techniques on an extra jet. We also show the complementarity between the LHC and canonical dark matter experiments in exploring the viable parameter space of the models.
Tau neutrinos favored over sterile neutrinos in atmospheric muon neutrino oscillations.
Fukuda, S; Fukuda, Y; Ishitsuka, M; Kajita, T; Kameda, J; Kaneyuki, K; Kobayashi, K; Koshio, Y; Miura, M; Moriyama, S; Nakahata, M; Nakayama, S; Obayashi, Y; Okada, A; Okumura, K; Sakurai, N; Shiozawa, M; Suzuki, Y; Takeuchi, H; Takeuchi, Y; Toshito, T; Totsuka, Y; Yamada, S; Earl, M; Habig, A; Kearns, E; Messier, M D; Scholberg, K; Stone, J L; Sulak, L R; Walter, C W; Goldhaber, M; Barszczak, T; Casper, D; Gajewski, W; Kropp, W R; Mine, S; Price, L R; Smy, M; Sobel, H W; Vagins, M R; Ganezer, K S; Keig, W E; Ellsworth, R W; Tasaka, S; Kibayashi, A; Learned, J G; Matsuno, S; Takemori, D
2000-11-01
The previously published atmospheric neutrino data did not distinguish whether muon neutrinos were oscillating into tau neutrinos or sterile neutrinos, as both hypotheses fit the data. Using data recorded in 1100 live days of the Super-Kamiokande detector, we use three complementary data samples to study the difference in zenith angle distribution due to neutral currents and matter effects. We find no evidence favoring sterile neutrinos, and reject the hypothesis at the 99% confidence level. On the other hand, we find that oscillation between muon and tau neutrinos suffices to explain all the results in hand.
No-neutrino double beta decay: more than one neutrino
Rosen, S.P.
1983-01-01
Interference effects between light and heavy Majorana neutrinos in the amplitude for no-neutrino double beta decay are discussed. The effects include an upper bound on the heavy neutrino mass, and an A dependence for the effective mass extracted from double beta decay. Thus the search for the no-neutrino decay mode should be pursued in several nuclei, and particularly in Ca/sup 48/, where the effective mass may be quite large.
A letter of intent for a neutrino scattering experiment on the booster neutrino meanline: FINeSSE
Fleming, B.T.; Tayloe, R.; /Indiana U. /Yale U.
2005-03-01
The experiment described in this Letter of Intent provides a decisive measurement of {Delta}s, the spin of the nucleon carried by strange quarks. This is crucial as, after more than thirty years of study, the spin contribution of strange quarks to the nucleon is still not understood. The interpretation of {Delta}s measurements from inclusive Deep Inelastic Scattering (DIS) experiments using charged leptons suffers from two questionable techniques; an assumption of SU(3)-flavor symmetry, and an extrapolation into unmeasured kinematic regions, both of which provide ample room for uncertain theoretical errors in the results. The results of recent semi-inclusive DIS data from HERMES paint a somewhat different picture of the contribution of strange quarks to the nucleon spin than do the inclusive results, but since HERMES does not make use of either of the above-mentioned techniques, then the results are somewhat incomparable. What is required is a measurement directly probing the spin contribution of the strange quarks in the nucleon. Neutrino experiments provide a theoretically clean and robust method of determining {Delta}s by comparing the neutral current interaction, which is isoscalar plus isovector, to the charged current interaction, which is strictly isovector. A past experiment, E734, performed at Brookhaven National Laboratory, has pioneered this effort. Building on what they have learned, we present an experiment which achieves a measurement to {+-} 0.025 using neutrino scattering, and {+-} 0.04 using anti-neutrino scattering, significantly better than past measurements. The combination of the neutrino and anti-neutrino data, when combined with the results of the parity-violating electron-nucleon scattering data, will produce the most significant result for {Delta}s. This experiment can also measure neutrino cross sections in the energy range required for accelerator-based precision oscillation measurements. Accurate measurements of cross sections have been
Baryogenesis from symmetry principle
NASA Astrophysics Data System (ADS)
Fong, Chee Sheng
2016-01-01
In this work, a formalism based on symmetry which allows one to express asymmetries of all the particles in terms of conserved charges is developed. The manifestation of symmetry allows one to easily determine the viability of a baryogenesis scenario and also to identify the different roles played by the symmetry. This formalism is then applied to the standard model and its supersymmetric extension, which constitute two important foundations for constructing models of baryogenesis.
Constraints on secret neutrino interactions after Planck
NASA Astrophysics Data System (ADS)
Forastieri, Francesco; Lattanzi, Massimiliano; Natoli, Paolo
2015-07-01
Neutrino interactions beyond the standard model of particle physics may affect the cosmological evolution and can be constrained through observations. We consider the possibility that neutrinos possess secret scalar or pseudoscalar interactions mediated by the Nambu-Goldstone boson of a still unknown spontaneously broken global U(1) symmetry, as in, e.g., Majoron models. In such scenarios, neutrinos still decouple at Tsimeq 1 MeV, but become tightly coupled again (``recouple'') at later stages of the cosmological evolution. We use available observations of the cosmic microwave background (CMB) anisotropies, including Planck 2013 and the joint BICEP2/Planck 2015 data, to derive constraints on the quantity γνν4, parameterizing the neutrino collision rate due to scalar or pseudoscalar interactions. We consider both a minimal extension of the standard ΛCDM model, and more complicated scenarios with extra relativistic degrees of freedom or non-vanishing tensor amplitude. For a wide range of dataset and model combinations, we find a typical constraint γνν4 lesssim 0.9× 10-27 (95% C.L.), implying an upper limit on the redshift zνrec of neutrino recoupling 0lesssim 850, leaving open the possibility that the latter occured well before hydrogen recombination. In the framework of Majoron models, the upper limit on γνν roughly translates on a constraint g lesssim 8.2× 10-7 on the Majoron-neutrino coupling constant g. In general, the data show a weak (~ 1σ) but intriguing preference for non-zero values of γνν4, with best fits in the range γνν4 = (0.15-0.35)× 10-27, depending on the particular dataset. This is more evident when either high-resolution CMB observations from the ACT and SPT experiments are included, or the possibility of non-vanishing tensor modes is considered. In particular, for the minimal model ΛCDM+γνν and including the Planck 2013, ACT and SPT data, we report γνν4=(0.44+0.17-0.36)×10-27 (0300 lesssim zνrec lesssim 550) at 68
Atmospheric neutrinos in ice and measurement of neutrino oscillation parameters
Fernandez-Martinez, Enrique; Giordano, Gerardo; Mocioiu, Irina; Mena, Olga
2010-11-01
The main goal of the IceCube Deep Core array is to search for neutrinos of astrophysical origins. Atmospheric neutrinos are commonly considered as a background for these searches. We show that the very high statistics atmospheric neutrino data can be used to obtain precise measurements of the main oscillation parameters.
Secondary atmospheric tau neutrino production
Bulmahn, Alexander; Hall Reno, Mary
2010-09-01
We evaluate the flux of tau neutrinos produced from the decay of pair produced taus from incident muons using a cascade equation analysis. To solve the cascade equations, our numerical result for the tau production Z moment is given. Our results for the flux of tau neutrinos produced from incident muons are compared to the flux of tau neutrinos produced via oscillations and the direct prompt atmospheric tau neutrino flux. Results are given for both downward and upward going neutrinos fluxes and higher zenith angles are discussed. We conclude that the direct prompt atmospheric tau neutrino flux dominates these other atmospheric sources of tau neutrinos for neutrino energies larger than a few TeV for upward fluxes, and over a wider range of energy for downward fluxes.
Hadronization processes in neutrino interactions
Katori, Teppei; Mandalia, Shivesh
2015-10-15
Next generation neutrino oscillation experiments utilize details of hadronic final states to improve the precision of neutrino interaction measurements. The hadronic system was often neglected or poorly modelled in the past, but they have significant effects on high precision neutrino oscillation and cross-section measurements. Among the physics of hadronic systems in neutrino interactions, the hadronization model controls multiplicities and kinematics of final state hadrons from the primary interaction vertex. For relatively high invariant mass events, many neutrino experiments rely on the PYTHIA program. Here, we show a possible improvement of this process in neutrino event generators, by utilizing expertise from the HERMES experiment. Finally, we estimate the impact on the systematics of hadronization models for neutrino mass hierarchy analysis using atmospheric neutrinos such as the PINGU experiment.
Crossmodal integration between visual linguistic information and flavour perception.
Razumiejczyk, Eugenia; Macbeth, Guillermo; Marmolejo-Ramos, Fernando; Noguchi, Kimihiro
2015-08-01
Many studies have found processing interference in working memory when complex information that enters the cognitive system from different modalities has to be integrated to understand the environment and promote adjustment. Here, we report on a Stroop study that provides evidence concerned with the crossmodal processing of flavour perception and visual language. We found a facilitation effect in the congruency condition. Acceleration was observed for incomplete words and anagrams compared to complete words. A crossmodal completion account is presented for such findings. It is concluded that the crossmodal integration between flavour and visual language perception requires the active participation of top-down and bottom-up processing. PMID:25843936
Heavy-flavour production in hot quark matter
Mischke, Andre
2011-05-23
Recent results from the RHIC facility and first measurements from the ALICE experiment at the CERN-Large Hadron Collider (LHC) on open heavy-flavour are presented. We focus on RHIC measurements of single electrons and jetlike heavy-flavour particle correlations. First D meson signals from 7 TeV proton-proton collisions from ALICE are discussed. Next-to-leading-order QCD processes, such as gluon splitting, become important at LHC energies and its contribution can be accesses by the measurement of the charm content in jets.
Probing Lepton Flavour Violation in Scenarios with Stau NLSP
Ibarra, Alejandro
2005-12-02
In this talk we discuss the prospects of probing lepton flavour violation in future experiments, in scenarios where the gravitino is the lightest supersymmetric particle. In this class of scenarios, different cosmological and theoretical considerations point to the possibility that the next-to-lightest supersymmetric particle (NLSP) is a right-handed stau. Since the NLSP can only decay gravitationally into gravitinos, their lifetimes could be very large. If this is the case, the NLSP would decay outside the detector, or could even be trapped in the walls of the detector for a long time. These features have interesting consequences for the search of lepton flavour violation, that are discussed here.
Novel tomato flavours introduced by plastidial terpenoid pathway engineering.
Mollet, Beat; Niederberger, Peter; Pétiard, Vincent
2008-01-01
Until recently breeding efforts centred on high-yield production while sacrificing flavour and taste quality traits of mass produced food products, such as tomatoes. The recent publication of Davidovich-Rikanati et al. demonstrates the technical feasibility of the genetical engineering of pathways in tomato plants to modify their fruit flavour profile in a proof-of-concept approach. The reported work ranks among an increasing number of reported successful modifications of edible plants with a focus on the benefits to end-consumers.
Heavy neutrino impact on the triple Higgs coupling
NASA Astrophysics Data System (ADS)
Baglio, J.; Weiland, C.
2016-07-01
We present the first calculation of the one-loop corrections to the triple Higgs coupling in the framework of a simplified 3 +1 Dirac neutrino model, that is three light neutrinos plus one heavy neutrino embedded in the Standard Model (SM). The triple Higgs coupling is a key parameter of the scalar potential triggering the electroweak symmetry-breaking mechanism in the SM. The impact of the heavy neutrino can be as large as +20 % to +30 % for parameter points allowed by the current experimental constraints depending on the tightness of the perturbative bound. This can be probed at the high-luminosity LHC, at future electron-positron colliders and at the Future Circular Collider in hadron-hadron mode, an envisioned 100 TeV p p machine. Our calculation, being done in the mass basis, can be extended to any model using the neutrino portal. In addition, the effects that we have calculated are expected to be enhanced if additional heavy fermions with large Yukawa couplings are included, as in low-scale seesaw mechanisms.
NASA Astrophysics Data System (ADS)
Abbas, Mohammed; Khalil, Shaaban; Rashed, Ahmed; Sil, Arunansu
2016-01-01
We propose a scheme, based on Δ (27 ) flavor symmetry and supplemented by other discrete symmetries and the inverse seesaw mechanism, where both the light neutrino masses and the deviation from tribimaximal mixing matrix can be linked to the source of lepton number violation. The hierarchies of the charged leptons are explained. We find that the quark masses including their hierarchies and the mixing can also be constructed in a similar way.
Results from Neutrino Oscillations Experiments
Aguilar-Arevalo, Alexis
2010-09-10
The interpretation of the results of early solar and atmospheric neutrino experiments in terms of neutrino oscillations has been verified by several recent experiments using both, natural and man-made sources. The observations provide compelling evidence in favor of the existence of neutrino masses and mixings. These proceedings give a general description of the results from neutrino oscillation experiments, the current status of the field, and some possible future developments.
Neutrino Masses and Flavor Mixing
NASA Astrophysics Data System (ADS)
Xing, Zhi-zhong
2010-06-01
I give a theoretical overview of some basic properties of massive neutrinos in these lectures. Particular attention is paid to the origin of neutrino masses, the pattern of lepton flavor mixing, the feature of leptonic CP violation and the electromagnetic properties of massive neutrinos. I highlight the TeV seesaw mechanisms as a possible bridge between neutrino physics and collider physics in the era characterized by the Large Hadron Collider.
Testing sterile neutrino extensions of the Standard Model at the Circular Electron Positron Collider
NASA Astrophysics Data System (ADS)
Antusch, Stefan; Fischer, Oliver
2015-08-01
Extending the Standard Model with sterile (“right-handed”) neutrinos is one of the best motivated ways to account for the observed neutrino masses. We discuss the expected sensitivity of the Circular Electron Positron Collider (CEPC) for testing such extensions. An interesting scenario is given by symmetry protected seesaw models, which theoretically allow for sterile neutrino masses around the electroweak scale with up to order one mixings with the active (SM) neutrinos. When the masses of the sterile neutrinos are well above the electroweak scale, they affect precision data via effective non-unitarity of the leptonic mixing matrix in a model independent way. The expected improvement of the electroweak precision observables from the CEPC may allow to test mixings between active and sterile neutrinos down to ˜ 5 × 10-3 (using currently discussed CEPC performance parameters). For sterile neutrinos with masses around the electroweak scale, direct searches are possible. Such tests are given by the search for sterile neutrino decays at the Z pole, by deviations from the SM cross section for four leptons at and beyond the W threshold, and by Higgs boson production and decays. The expected sensitivities at the CEPC could reach down to mixings as small as ˜ 5 × 10-5.
Gravitational Lensing of Supernova Neutrinos
Mena, Olga; Mocioiu, Irina; Quigg, Chris; /Fermilab
2006-10-01
The black hole at the center of the galaxy is a powerful lens for supernova neutrinos. In the very special circumstance of a supernova near the extended line of sight from Earth to the galactic center, lensing could dramatically enhance the neutrino flux at Earth and stretch the neutrino pulse.
Neutrino sea scope takes shape
NASA Astrophysics Data System (ADS)
Cartlidge, Edwin
2016-03-01
A consortium of European physicists building a vast neutrino detector on the floor of the Mediterranean Sea has unveiled the science it will carry out. The Cubic Kilometre Neutrino Telescope (KM3NeT) will use strings of radiation detectors arranged in a 3D network to measure the light emitted when neutrinos very occasionally interact with the surrounding sea water.
NASA Astrophysics Data System (ADS)
Abreu, P.; Aglietta, M.; Ahlers, M.; Ahn, E. J.; Albuquerque, I. F. M.; Allard, D.; Allekotte, I.; Allen, J.; Allison, P.; Almela, A.; Alvarez Castillo, J.; Alvarez-Muñiz, J.; Ambrosio, M.; Aminaei, A.; Anchordoqui, L.; Andringa, S.; Anticic, T.; Aramo, C.; Arganda, E.; Arqueros, F.; Asorey, H.; Assis, P.; Aublin, J.; Ave, M.; Avenier, M.; Avila, G.; Bäcker, T.; Badescu, A. M.; Balzer, M.; Barber, K. B.; Barbosa, A. F.; Bardenet, R.; Barroso, S. L. C.; Baughman, B.; Bäuml, J.; Beatty, J. J.; Becker, B. R.; Becker, K. H.; Bellétoile, A.; Bellido, J. A.; Benzvi, S.; Berat, C.; Bertou, X.; Biermann, P. L.; Billoir, P.; Blanco, F.; Blanco, M.; Bleve, C.; Blümer, H.; Bohácová, M.; Boncioli, D.; Bonifazi, C.; Bonino, R.; Borodai, N.; Brack, J.; Brancus, I.; Brogueira, P.; Brown, W. C.; Bruijn, R.; Buchholz, P.; Bueno, A.; Burton, R. E.; Caballero-Mora, K. S.; Caccianiga, B.; Caramete, L.; Caruso, R.; Castellina, A.; Catalano, O.; Cataldi, G.; Cazon, L.; Cester, R.; Chauvin, J.; Cheng, S. H.; Chiavassa, A.; Chinellato, J. A.; Chirinos Diaz, J.; Chudoba, J.; Clay, R. W.; Coluccia, M. R.; Conceição, R.; Contreras, F.; Cook, H.; Cooper, M. J.; Coppens, J.; Cordier, A.; Coutu, S.; Covault, C. E.; Creusot, A.; Criss, A.; Cronin, J.; Curutiu, A.; Dagoret-Campagne, S.; Dallier, R.; Dasso, S.; Daumiller, K.; Dawson, B. R.; de Almeida, R. M.; de Domenico, M.; de Donato, C.; de Jong, S. J.; de La Vega, G.; de Mello, W. J. M., Jr.; de Mello Neto, J. R. T.; de Mitri, I.; de Souza, V.; de Vries, K. D.; Del Peral, L.; Del Río, M.; Deligny, O.; Dembinski, H.; Dhital, N.; di Giulio, C.; Díaz Castro, M. L.; Diep, P. N.; Diogo, F.; Dobrigkeit, C.; Docters, W.; D'Olivo, J. C.; Dong, P. N.; Dorofeev, A.; Dos Anjos, J. C.; Dova, M. T.; D'Urso, D.; Dutan, I.; Ebr, J.; Engel, R.; Erdmann, M.; Escobar, C. O.; Espadanal, J.; Etchegoyen, A.; Facal San Luis, P.; Fajardo Tapia, I.; Falcke, H.; Farrar, G.; Fauth, A. C.; Fazzini, N.; Ferguson, A. P.; Fick, B.; Filevich, A.; Filipcic, A.; Fliescher, S.; Fracchiolla, C. E.; Fraenkel, E. D.; Fratu, O.; Fröhlich, U.; Fuchs, B.; Gaior, R.; Gamarra, R. F.; Gambetta, S.; García, B.; Garcia Roca, S. T.; Garcia-Gamez, D.; Garcia-Pinto, D.; Gascon, A.; Gemmeke, H.; Ghia, P. L.; Giaccari, U.; Giller, M.; Glass, H.; Gold, M. S.; Golup, G.; Gomez Albarracin, F.; Gómez Berisso, M.; Gómez Vitale, P. F.; Gonçalves, P.; Gonzalez, D.; Gonzalez, J. G.; Gookin, B.; Gorgi, A.; Gouffon, P.; Grashorn, E.; Grebe, S.; Griffith, N.; Grigat, M.; Grillo, A. F.; Guardincerri, Y.; Guarino, F.; Guedes, G. P.; Guzman, A.; Hansen, P.; Harari, D.; Harmsma, S.; Harrison, T. A.; Harton, J. L.; Haungs, A.; Hebbeker, T.; Heck, D.; Herve, A. E.; Hojvat, C.; Hollon, N.; Holmes, V. C.; Homola, P.; Hörandel, J. R.; Horneffer, A.; Horvath, P.; Hrabovský, M.; Huber, D.; Huege, T.; Insolia, A.; Ionita, F.; Italiano, A.; Jarne, C.; Jiraskova, S.; Josebachuili, M.; Kadija, K.; Kampert, K. H.; Karhan, P.; Kasper, P.; Kégl, B.; Keilhauer, B.; Keivani, A.; Kelley, J. L.; Kemp, E.; Kieckhafer, R. M.; Klages, H. O.; Kleifges, M.; Kleinfeller, J.; Knapp, J.; Koang, D.-H.; Kotera, K.; Krohm, N.; Krömer, O.; Kruppke-Hansen, D.; Kuehn, F.; Kuempel, D.; Kulbartz, J. K.; Kunka, N.; La Rosa, G.; Lachaud, C.; Lauer, R.; Lautridou, P.; Le Coz, S.; Leão, M. S. A. B.; Lebrun, D.; Lebrun, P.; Leigui de Oliveira, M. A.; Letessier-Selvon, A.; Lhenry-Yvon, I.; Link, K.; López, R.; Lopez Agüera, A.; Louedec, K.; Lozano Bahilo, J.; Lu, L.; Lucero, A.; Ludwig, M.; Lyberis, H.; Macolino, C.; Maldera, S.; Mandat, D.; Mantsch, P.; Mariazzi, A. G.; Marin, J.; Marin, V.; Maris, I. C.; Marquez Falcon, H. R.; Marsella, G.; Martello, D.; Martin, L.; Martinez, H.; Martínez Bravo, O.; Mathes, H. J.; Matthews, J.; Matthews, J. A. J.; Matthiae, G.; Maurel, D.; Maurizio, D.; Mazur, P. O.; Medina-Tanco, G.; Melissas, M.; Melo, D.; Menichetti, E.; Menshikov, A.; Mertsch, P.; Meurer, C.; Micanovic, S.; Micheletti, M. I.; Miramonti, L.; Molina-Bueno, L.; Mollerach, S.; Monasor, M.; Monnier Ragaigne, D.; Montanet, F.; Morales, B.; Morello, C.; Moreno, E.; Moreno, J. C.; Mostafá, M.; Moura, C. A.; Muller, M. A.; Müller, G.; Münchmeyer, M.; Mussa, R.; Navarra, G.; Navarro, J. L.; Navas, S.; Necesal, P.; Nellen, L.; Nelles, A.; Neuser, J.; Newton, D.; Nhung, P. T.; Niechciol, M.; Niemietz, L.; Nierstenhoefer, N.; Nitz, D.; Nosek, D.; Nožka, L.; Nyklicek, M.; Oehlschläger, J.; Olinto, A.; Ortiz, M.; Pacheco, N.; Pakk Selmi-Dei, D.; Palatka, M.; Pallotta, J.; Palmieri, N.; Parente, G.; Parizot, E.; Parra, A.; Pastor, S.; Paul, T.; Pech, M.; Pekala, J.; Pelayo, R.; Pepe, I. M.; Perrone, L.; Pesce, R.; Petermann, E.; Petrera, S.; Petrinca, P.; Petrolini, A.; Petrov, Y.; Pfendner, C.; Piegaia, R.; Pierog, T.; Pieroni, P.; Pimenta, M.; Pirronello, V.; Platino, M.; Ponce, V. H.; Pontz, M.; Porcelli, A.; Privitera, P.; Prouza, M.; Quel, E. J.; Querchfeld, S.; Rautenberg, J.; Ravel, O.; Ravignani, D.; Revenu, B.; Ridky, J.; Riggi, S.; Risse, M.; Ristori, P.; Rivera, H.; Rizi, V.; Roberts, J.; Rodrigues de Carvalho, W.; Rodriguez, G.; Rodriguez Martino, J.; Rodriguez Rojo, J.; Rodriguez-Cabo, I.; Rodríguez-Frías, M. D.; Ros, G.; Rosado, J.; Rossler, T.; Roth, M.; Rouillé-D'Orfeuil, B.; Roulet, E.; Rovero, A. C.; Rühle, C.; Saftoiu, A.; Salamida, F.; Salazar, H.; Salesa Greus, F.; Salina, G.; Sánchez, F.; Santo, C. E.; Santos, E.; Santos, E. M.; Sarazin, F.; Sarkar, B.; Sarkar, S.; Sato, R.; Scharf, N.; Scherini, V.; Schieler, H.; Schiffer, P.; Schmidt, A.; Scholten, O.; Schoorlemmer, H.; Schovancova, J.; Schovánek, P.; Schröder, F.; Schulte, S.; Schuster, D.; Sciutto, S. J.; Scuderi, M.; Segreto, A.; Settimo, M.; Shadkam, A.; Shellard, R. C.; Sidelnik, I.; Sigl, G.; Silva Lopez, H. H.; Sima, O.; Smialkowski, A.; Šmída, R.; Snow, G. R.; Sommers, P.; Sorokin, J.; Spinka, H.; Squartini, R.; Srivastava, Y. N.; Stanic, S.; Stapleton, J.; Stasielak, J.; Stephan, M.; Stutz, A.; Suarez, F.; Suomijärvi, T.; Supanitsky, A. D.; Šuša, T.; Sutherland, M. S.; Swain, J.; Szadkowski, Z.; Szuba, M.; Tapia, A.; Tartare, M.; Tascau, O.; Tavera Ruiz, C. G.; Tcaciuc, R.; Tegolo, D.; Thao, N. T.; Thomas, D.; Tiffenberg, J.; Timmermans, C.; Tkaczyk, W.; Todero Peixoto, C. J.; Toma, G.; Tomé, B.; Tonachini, A.; Travnicek, P.; Tridapalli, D. B.; Tristram, G.; Trovato, E.; Tueros, M.; Ulrich, R.; Unger, M.; Urban, M.; Valdés Galicia, J. F.; Valiño, I.; Valore, L.; van den Berg, A. M.; Varela, E.; Vargas Cárdenas, B.; Vázquez, J. R.; Vázquez, R. A.; Veberic, D.; Verzi, V.; Vicha, J.; Videla, M.; Villaseñor, L.; Wahlberg, H.; Wahrlich, P.; Wainberg, O.; Walz, D.; Watson, A. A.; Weber, M.; Weidenhaupt, K.; Weindl, A.; Werner, F.; Westerhoff, S.; Whelan, B. J.; Widom, A.; Wieczorek, G.; Wiencke, L.; Wilczynska, B.; Wilczynski, H.; Will, M.; Williams, C.; Winchen, T.; Wommer, M.; Wundheiler, B.; Yamamoto, T.; Yapici, T.; Younk, P.; Yuan, G.; Yushkov, A.; Zamorano, B.; Zas, E.; Zavrtanik, D.; Zavrtanik, M.; Zaw, I.; Zepeda, A.; Zhu, Y.; Zimbres Silva, M.; Ziolkowski, M.
2012-01-01
The Surface Detector of the Pierre Auger Observatory is sensitive to neutrinos of all flavours above 0.1 EeV. These interact through charged and neutral currents in the atmosphere giving rise to extensive air showers. When interacting deeply in the atmosphere at nearly horizontal incidence, neutrinos can be distinguished from regular hadronic cosmic rays by the broad time structure of their shower signals in the water-Cherenkov detectors. In this paper we present for the first time an analysis based on down-going neutrinos. We describe the search procedure, the possible sources of background, the method to compute the exposure and the associated systematic uncertainties. No candidate neutrinos have been found in data collected from 1 January 2004 to 31 May 2010. Assuming an E^-2 differential energy spectrum the limit on the single flavour neutrino is (E^2 * dN/dE) < 1.74x10^-7 GeV cm^-2 s^-1 sr^-1 at 90% C.L. in the energy range 1x10^17 eV < E < 1x10^20 eV.
Strong thermal leptogenesis and the absolute neutrino mass scale
Bari, Pasquale Di; King, Sophie E.; Fiorentin, Michele Re E-mail: sk1806@soton.ac.uk
2014-03-01
We show that successful strong thermal leptogenesis, where the final asymmetry is independent of the initial conditions and in particular a large pre-existing asymmetry is efficiently washed-out, favours values of the lightest neutrino mass m{sub 1}∼>10 meV for normal ordering (NO) and m{sub 1}∼>3 meV for inverted ordering (IO) for models with orthogonal matrix entries respecting |Ω{sub ij}{sup 2}|∼<2. We show analytically why lower values of m{sub 1} require a higher level of fine tuning in the seesaw formula and/or in the flavoured decay parameters (in the electronic for NO, in the muonic for IO). We also show how this constraint exists thanks to the measured values of the neutrino mixing angles and could be tightened by a future determination of the Dirac phase. Our analysis also allows us to place a more stringent constraint for a specific model or class of models, such as SO(10)-inspired models, and shows that some models cannot realise strong thermal leptogenesis for any value of m{sub 1}. A scatter plot analysis fully supports the analytical results. We also briefly discuss the interplay with absolute neutrino mass scale experiments concluding that they will be able in the coming years to either corner strong thermal leptogenesis or find positive signals pointing to a non-vanishing m{sub 1}. Since the constraint is much stronger for NO than for IO, it is very important that new data from planned neutrino oscillation experiments will be able to solve the ambiguity.
Symmetry in Mathematics Learning.
ERIC Educational Resources Information Center
Dreyfus, Tommy; Eisenberg, Theodore
1989-01-01
Discusses the creed in symmetry and the omnipresence of symmetrical relationships in mathematics and nature, discusses mathematicians' attraction toward looking for symmetrical relationships as an unstated problem-solving heuristic, and shows how symmetry can be used as a didactical tool. (Author/MKR)
ERIC Educational Resources Information Center
Marchis, Iuliana
2009-01-01
Symmetry is one of the fundamental concepts in Geometry. It is a Mathematical concept, which can be very well connected with Art and Ethnography. The aim of the article is to show how to link the geometrical concept symmetry with interculturality. For this mosaics from different countries are used.
Symmetries in Lagrangian Dynamics
ERIC Educational Resources Information Center
Ferrario, Carlo; Passerini, Arianna
2007-01-01
In the framework of Noether's theorem, a distinction between Lagrangian and dynamical symmetries is made, in order to clarify some aspects neglected by textbooks. An intuitive setting of the concept of invariance of differential equations is presented. The analysis is completed by deriving the symmetry properties in the motion of a charged…
Symmetry Effects in Computation
NASA Astrophysics Data System (ADS)
Yao, Andrew Chi-Chih
2008-12-01
The concept of symmetry has played a key role in the development of modern physics. For example, using symmetry, C.N. Yang and other physicists have greatly advanced our understanding of the fundamental laws of physics. Meanwhile, computer scientists have been pondering why some computational problems seem intractable, while others are easy. Just as in physics, the laws of computation sometimes can only be inferred indirectly by considerations of general principles such as symmetry. The symmetry properties of a function can indeed have a profound effect on how fast the function can be computed. In this talk, we present several elegant and surprising discoveries along this line, made by computer scientists using symmetry as their primary tool. Note from Publisher: This article contains the abstract only.
Probing Late Neutrino Mass Properties With SupernovaNeutrinos
Baker, Joseph; Goldberg, Haim; Perez, Gilad; Sarcevic, Ina
2007-08-08
Models of late-time neutrino mass generation contain new interactions of the cosmic background neutrinos with supernova relic neutrinos (SRNs). Exchange of an on-shell light scalar may lead to significant modification of the differential SRN flux observed at earth. We consider an Abelian U(1) model for generating neutrino masses at low scales, and show that there are cases for which the changes induced in the flux allow one to distinguish the Majorana or Dirac nature of neutrinos, as well as the type of neutrino mass hierarchy (normal or inverted or quasi-degenerate). In some region of parameter space the determination of the absolute values of the neutrino masses is also conceivable. Measurements of the presence of these effects may be possible at the next-generation water Cerenkov detectors enriched with Gadolinium, or a 100 kton liquid argon detector.
Perinatal Flavour Learning and Adaptation to Being Weaned: All the Pig Needs Is Smell
Oostindjer, Marije; Bolhuis, J. Elizabeth; Simon, Kristina; van den Brand, Henry; Kemp, Bas
2011-01-01
Perinatal flavour learning through the maternal diet is known to enhance flavour preference and acceptance of flavoured food in many species, yet still little is known about the mechanism underlying perinatal flavour learning. Previously we found positive effects of perinatal flavour learning on food intake, growth and behaviour of piglets postweaning, but no increased preference for the flavour. This suggests that flavour learning in pigs works through a reduction of weaning stress by the presence of the familiar flavour instead. The aim of this study was to investigate whether perinatal flavour learning reduces stress at weaning, and whether the effect is stronger when the familiar flavour is present in the food. Sows were offered an anethol-flavoured diet (Flavour treatment) or control diet (Control treatment) during late gestation and lactation. Flavour and Control piglets were provided with anethol either in their food (Food treatment) or in the air (Air treatment) after weaning. Preweaning and postweaning treatments did not affect food intake, preference or growth in the first two weeks postweaning but flavour treatment reduced the latency to eat (24 versus 35 hours, P = 0.02) and within-pen variation in growth (SD within-pen: 0.7 versus 1.2 kg, P<0.001). Salivary cortisol levels tended to be lower four and seven hours postweaning for Flavour piglets compared to Control piglets (4 hours: 2.5 versus 3.0 ng/ml, P = 0.05, 7 hours: 3.1 versus 3.4 ng/ml, P = 0.08). Flavour piglets played more and showed less damaging behaviours than Control piglets, indicating that the familiar flavour reduced stress around weaning. Few interaction effects were found between preweaning and postweaning treatment, and no effects of postweaning treatment. We conclude that in the newly weaned pig, perinatal flavour learning results in a reduction of stress when the familiar flavour is present, regardless of providing the flavour in the food or in the air. PMID:22039409
B Flavour Tagging with Artificial Neural Networks for the CDF II Experiment
Schmidt, Andreas
2010-01-29
gravity, dark matter and dark energy are not described, and open questions remain in the sector of neutrino masses and neutrino oscillations. Also no answer has been given to the question of matter-antimatter asymmetry observed in the contemporary universe. Assuming that the Big Bang created equal amounts of matter and antimatter, there must be effects where nature treats matter and antimatter somehow different. This can happen through a mechanism called CP violation, which has been observed within the Standard Model, but not in the necessary order of magnitude. For all these reasons, the search for New Physics - theories beyond the Standard Model - is one of the main objectives of modern particle physics. In this global effort, flavour physics is the field of transitions between the different types of quarks, called quark flavours, wherein the examination of B meson oscillations and the search for CP violation in B{sub s}{sup 0} meson decays set the stage for the work presented in this thesis.
Cosmology and neutrino physics
NASA Astrophysics Data System (ADS)
Steigman, Gary
1982-05-01
Constraints on cosmology and on neutrino physics are provided by the abundances of the light elements produced during the early evolution of the universe. The predictions of primordial nucleosynthesis depend on the nucleon to photon ratio ɛ and on the number of types of two component neutrinos Nν. A comparison between the big bang predictions and the observed abundances of D, 3He, 4He and 7Li shows that ɛ is constrained to a narrow range around 4×10-10 and Nν<~4. An important consequence of the derived value of ɛ is that the universal density of nucleon is small, raising the possibility that our Universe may be dominated by massive relic neutrinos. The constraint on Nn suggests that (almost) all lepton species are now known.
The Neutrino Telescope ANTARES
NASA Astrophysics Data System (ADS)
Hernández, Juan José
Neutrinos can reveal a brand new Universe at high energies. The ANTARES collaboration [1] , formed in 1996, works towards the building and deployment of a neutrino telescope. This detector could observe and study high energy astrophysical sources such as X-ray binary systems, young supernova remnants or Active Galactic Nuclei and help to discover or set exclusion limits on some of the elementary particles and objects that have been put forward as candidates to fill the Universe (WIMPS, neutralinos, topological deffects, Q-balls, etc). A neutrino telescope will certainly open a new observational window and can shed light on the most energetic phenomena of the Universe. A review of the progress made by the ANTARES collaboration to achieve this goal is presented
Neutrino physics: Summary talk
Marciano, W.J.
1989-04-01
This paper is organized as follows: First, I describe the state of neutrino phenomenology. Emphasis is placed on sin/sup 2/ /theta//sub W/, its present status and future prospects. In addition, some signatures of ''new physics'' are described. Then, kaon physics at Fermilab is briefly discussed. I concentrate on the interesting rare decay K/sub L/ /yields/ /pi//sup 0/e/sup +/e/sup /minus// which may be a clean probe direct CP violation. Neutrino mass, mixing, and electromagnetic moments are surveyed. There, I describe the present state and future direction of accelerator based experiments. Finally, I conclude with an outlook on the future. Throughout this summary, I have drawn from and incorporated ideas discussed by other speakers at this workshop. However, I have tried to combine their ideas with my own perspective on neutrino physics and where it is headed. 49 refs., 3 figs., 4 tabs.
Väänänen, Daavid; Volpe, Cristina E-mail: volpe@ipno.in2p3.fr
2011-10-01
Core-collapse supernova neutrinos undergo a variety of phenomena when they travel from the high neutrino density region and large matter densities to the Earth. We perform analytical calculations of the supernova neutrino fluxes including collective effects due to the neutrino-neutrino interactions, the Mikheev-Smirnov-Wolfenstein (MSW) effect due to the neutrino interactions with the background matter and decoherence of the wave packets as they propagate in space. We predict the numbers of one- and two-neutron charged and neutral-current electron-neutrino scattering on lead events. We show that, due to the energy thresholds, the ratios of one- to two-neutron events are sensitive to the pinching parameters of neutrino fluxes at the neutrinosphere, almost independently of the presently unknown neutrino properties. Besides, such events have an interesting sensitivity to the spectral split features that depend upon the presence/absence of energy equipartition among neutrino flavors. Our calculations show that a lead-based observatory like the Helium And Lead Observatory (HALO) has the potential to pin down important characteristics of the neutrino fluxes at the neutrinosphere, and provide us with information on the neutrino transport in the supernova core.
Decay properties of charm and beauty open flavour mesons
Kumar Rai, Ajay; Vinodkumar, P. C.
2007-10-03
The masses of S and P states, pseudoscalar and vector decay constants, leptonic, semileptonic decay widths of charm (D) and beauty (B) open flavour mesons have been computed in the framework of Coulomb and power potential of the form V(r) = -({alpha}{sub c}/r)+Ar{sup v}. The results are compared with other theoretical as well as experimental results.
B lifetimes and flavour tagging at CDF Run II
Farrington, S.M.; /Glasgow U.
2004-01-01
Data samples of {approx} 140pb{sup -1} gathered with CDF Run II's displaced vertex trigger and J/{Psi} trigger have led to measurements of B hadron lifetimes in exclusive and semileptonic modes which are presented here. Also discussed are evaluations of flavour tagging techniques in Run II data. .30.-a - 14.40.Nd.
Differential transfer of dietary flavour compounds into human breast milk.
Hausner, Helene; Bredie, Wender L P; Mølgaard, Christian; Petersen, Mikael Agerlin; Møller, Per
2008-09-01
Transfer of dietary flavour compounds into human milk is believed to constitute the infant's early flavour experiences. This study reports on the time-dependent transfer of flavour compounds from the mother's diet to her breast milk using a within-subject design. Eighteen lactating mothers completed three test days on which they provided a baseline milk sample prior to ingestion of capsules containing 100 mg d-carvone, l-menthol, 3-methylbutyl acetate and trans-anethole. Milk samples were collected 2, 4, 6 and 8 h post-ingestion and analysed by a dynamic headspace method and gas chromatography-mass spectroscopy. The recovery quantities were adjusted for variations in milk fat content. Concentration-time profiles for d-carvone and trans-anethole revealed a maximum around 2 h post-ingestion, whereas the profile for l-menthol showed a plateau pattern. The ester 3-methylbutyl acetate could not be detected in the milk, but a single determination showed traces (<0.4 ppb) in a 1 h milk collection. Flavour compounds appeared to be transmitted differentially from the mother's diet to her milk. The results imply that human milk provides a reservoir for time-dependent chemosensory experiences to the infant; however, volatiles from the diet are transferred selectively and in relatively low amounts.
NASA Astrophysics Data System (ADS)
McKinsey, D. N.; Coakley, K. J.
2005-01-01
This article describes CLEAN, an approach to the detection of low-energy solar neutrinos and neutrinos released from supernovae. The CLEAN concept is based on the detection of elastic scattering events (neutrino-electron scattering and neutrino-nuclear scattering) in liquified noble gases such as liquid helium, liquid neon, and liquid xenon, all of which scintillate brightly in the ultraviolet. Key to the CLEAN technique is the use of a thin film of wavelength-shifting fluor to convert the ultraviolet scintillation light to the visible, thereby allowing detection by conventional photomultipliers. Liquid neon is a particularly promising medium for CLEAN. Because liquid neon has a high scintillation yield, has no long-lived radioactive isotopes, and can be easily purified by use of cold traps, it is an ideal medium for the detection of rare nuclear events. In addition, neon is inexpensive, dense, and transparent to its own scintillation light, making it practical for use in a large self-shielding apparatus. The central region of a full-sized detector would be a stainless steel tank holding approximately 135 metric tons of liquid neon. Inside the tank and suspended in the liquid neon would be several thousand photomultipliers. Monte Carlo simulations of gamma ray backgrounds have been performed assuming liquid neon as both shielding and detection medium. Gamma ray events occur with high probability in the outer parts of the detector. In contrast, neutrino scattering events occur uniformly throughout the detector. We discriminate background gamma ray events from events of interest based on a spatial maximum likelihood method estimate of event location. Background estimates for CLEAN are presented, as well as an evaluation of the sensitivity of the detector for p-p neutrinos. Given these simulations, the physics potential of the CLEAN approach is evaluated.
NASA Astrophysics Data System (ADS)
Jediny, Filip
2015-06-01
The NOνA experiment is a long-baseline accelerator-based neutrino oscillation experiment. It uses the upgraded NuMI beam from Fermilab and measures electron-neutrino appearance and muon-neutrino disappearance at its far detector in Ash River, Minnesota. Goals of the experiment include measurements of θ13, mass hierarchy and the CP violating phase. NOνA has begun to take neutrino data and first neutrino candidates are observed in its detectors. This document provides an overview of the scientific reach of the experiment, the status of detector operation and physics analysis, as well as the first data.
Atmospheric neutrinos: Status and prospects
NASA Astrophysics Data System (ADS)
Choubey, Sandhya
2016-07-01
We present an overview of the current status of neutrino oscillation studies at atmospheric neutrino experiments. While the current data gives some tantalising hints regarding the neutrino mass hierarchy, octant of θ23 and δCP, the hints are not statistically significant. We summarise the sensitivity to these sub-dominant three-generation effects from the next-generation proposed atmospheric neutrino experiments. We next present the prospects of new physics searches such as non-standard interactions, sterile neutrinos and CPT violation studies at these experiments.
Are neutrinos their own antiparticles?
Kayser, Boris; /Fermilab
2009-03-01
We explain the relationship between Majorana neutrinos, which are their own antiparticles, and Majorana neutrino masses. We point out that Majorana masses would make the neutrinos very distinctive particles, and explain why many theorists strongly suspect that neutrinos do have Majorana masses. The promising approach to confirming this suspicion is to seek neutrinoless double beta decay. We introduce a toy model that illustrates why this decay requires nonzero neutrino masses, even when there are both right-handed and left-handed weak currents.
Solar Neutrinos. II. Experimental
DOE R&D Accomplishments Database
Davis, Raymond Jr.
1964-01-01
A method is described for observing solar neutrinos from the reaction Cl{sup 37}(nu,e{sup -})Ar{sup 37} in C{sub 2}Cl{sub 4}. Two 5 00-gal tanks of C{sub 2}Cl{sub 4} were placed in a limestone mine (1800 m.w.e.) and the resulting Ar{sup 37} activity induced by cosmic mesons( mu ) was measured to determine the necessary conditions for solar neutrino observations. (R.E.U.)
Sterile Neutrino Search with MINOS
Devan, Alena V.
2015-08-01
MINOS, Main Injector Neutrino Oscillation Search, is a long-baseline neutrino oscillation experiment in the NuMI muon neutrino beam at the Fermi National Accelerator Laboratory in Batavia, IL. It consists of two detectors, a near detector positioned 1 km from the source of the beam and a far detector 734 km away in Minnesota. MINOS is primarily designed to observe muon neutrino disappearance resulting from three flavor oscillations. The Standard Model of Particle Physics predicts that neutrinos oscillate between three active flavors as they propagate through space. This means that a muon-type neutrino has a certain probability to later interact as a different type of neutrino. In the standard picture, the neutrino oscillation probabilities depend only on three neutrino flavors and two mass splittings, Δm^{2}. An anomaly was observed by the LSND and MiniBooNE experiments that suggests the existence of a fourth, sterile neutrino flavor that does not interact through any of the known Standard Model interactions. Oscillations into a theoretical sterile flavor may be observed by a deficit in neutral current interactions in the MINOS detectors. A distortion in the charged current energy spectrum might also be visible if oscillations into the sterile flavor are driven by a large mass-squared difference, m_{s}^{2} ~ 1 eV^{2}. The results of the 2013 sterile neutrino search are presented here.
Experimental data on solar neutrinos
NASA Astrophysics Data System (ADS)
Ludhova, Livia
2016-04-01
Neutrino physics continues to be a very active research field, full of opened fundamental questions reaching even beyond the Standard Model of elementary particles and towards a possible new physics. Solar neutrinos have played a fundamental historical role in the discovery of the phenomenon of neutrino oscillations and thus non-zero neutrino mass. Even today, the study of solar neutrinos provides an important insight both into the neutrino as well as into the stellar and solar physics. In this section we give an overview of the most important solar-neutrino measurements from the historical ones up to the most recent ones. We cover the results from the experiments using radio-chemic (Homestake, SAGE, GNO, GALLEX), water Cherenkov (Kamiokande, Super-Kamiokande, SNO), and the liquid-scintillator (Borexino, KamLAND) detection techniques.