In this paper, the submicroscopic deterministic concept developed by the author is applied to the problem of the neutrino mass. A particle appears from space considered as a mathematical lattice of primary topological...In this paper, the submicroscopic deterministic concept developed by the author is applied to the problem of the neutrino mass. A particle appears from space considered as a mathematical lattice of primary topological balls, and induces a deformation coat in its surrounding. The principles of the interaction of particles with space and through space between themselves are considered in detail. The approach states that real quarks possess only an integer charge (±e) and when moving they periodically change to the monopole state (⇄g) and hence, canonical particles are dynamic dyons. A neutrino emerges as a squeezed quark when it is in a monopole state, or in other words, the quark monopole state (a bubble in the tessellattice) is transferred to the appropriate lepton monopole state (a speck in the tessellattice). The self-mass (a “rest” mass) for each neutrino flavour is calculated. The calculated value of the self-mass for the electron anti-neutrino is 1.22873978 × 10<sup>-36</sup> kg = 0.68927247 eV/c<sup>2</sup>. The concept of neutrino oscillations is revised, and another postulation is proposed, namely, that the transition from lighter to heavier flavors is due to the inelastic scattering of neutrinos on oncoming scatterers. As a result, the neutrino captures the mass defect, becomes heavier, and therefore the transitions V<sub>e</sub>⟶V<sub>μ</sub> and V<sub>μ</sub>⟶V<sub>τ</sub> occur;thus, the number of light neutrinos decreases in the neutrino flux studied.展开更多
We constrain two dynamical dark energy models that are parametrized by the logarithm form of and the oscillating form of . Comparing with the Chevallier-Polarski-Linder (CPL) model, the two parametrizations for dark e...We constrain two dynamical dark energy models that are parametrized by the logarithm form of and the oscillating form of . Comparing with the Chevallier-Polarski-Linder (CPL) model, the two parametrizations for dark energy can explore the whole evolution history of the universe properly. Using the current mainstream observational data including the cosmic microwave background data and the baryon acoustic oscillation data as well as the type Ia supernovae data, we perform the X<sup>2</sup> statistic analysis to global fit these models, finding that the logarithm parametrization and the oscillating parameterization are almost as well as the CPL scenario in fitting these data. We make a comparison for the impacts of the dynamical dark energy on the cosmological constraints on the total mass of active neutrinos. We find that the logarithm parametrization and the oscillating parameterization can increase the fitting values of Σm<sub>v</sub>. Looser constraints on Σm<sub>v</sub> are obtained in the logarithm and oscillating models than those derived in the CPL model. Consideration of the possible mass ordering of neutrinos reveals that the most stringent constraint on Σm<sub>v</sub> appears in the degenerate hierarchy case.展开更多
This paper aims at solving several open questions in current neutrino physics: the neutrino mass hierarchy, the Dirac CP violating phase, the absolute mass of neutrinos, the nature of neutrinos (Dirac or Majorana), th...This paper aims at solving several open questions in current neutrino physics: the neutrino mass hierarchy, the Dirac CP violating phase, the absolute mass of neutrinos, the nature of neutrinos (Dirac or Majorana), the Majorana matrix and the absolute value of the effective Majorana neutrino mass. In the research presented in this paper, we have shown that the precise definition of the mass splittings between neutrino mass eigenstates, done in the latest analysis of experimental data, can be of crucial importance for defining the nature of neutrino mass hierarchy. The Standard Model has three generations of fundamental matter particles. Three generations of the charged lepton mass show a hierarchical structure: m<sub>τ</sub> > m<sub>μ</sub> > m<sub>e</sub>. Owing to that, there is a belief and it is considered that neutrinos may follow such hierarchical structure. In our calculations, we have also included the latest data obtained, based on the processing of measurement results, which showed that even with such data, obtained results favor the normal neutrino mass hierarchy. As for the individual neutrino mass calculated in this paper, in today’s neutrino physics it is only known that neutrino mass scale is bounded only from above, and both the Dirac and the Majorana character of neutrinos are compatible with all observations. Among some of the questions resolved in this paper, which are related to the properties of neutrinos, a positive answer was also given to the question of whether light neutrinos are self-conjugate particles or not.展开更多
In this work the Generalized Special Relativity (GSR) is utilized to estimate masses of some elementary particles such as, neutrinos. These results are found to be in conformity with experimental and theoretical data....In this work the Generalized Special Relativity (GSR) is utilized to estimate masses of some elementary particles such as, neutrinos. These results are found to be in conformity with experimental and theoretical data. The results obtained may explain some physical phenomena, such as, conversion of neutrinos from type to type when solar neutrino reaches the Earth.展开更多
We study galaxy distributions with Sloan Digital Sky Survey SDSS DR14 data and with simulations searching for variables that can constrain neutrino masses. To be specific, we consider the scenario of three active neut...We study galaxy distributions with Sloan Digital Sky Survey SDSS DR14 data and with simulations searching for variables that can constrain neutrino masses. To be specific, we consider the scenario of three active neutrino eigenstates with approximately the same mass, so Σmv=3mv. Fitting the predictions of the ΛCDM model to the Sachs-Wolfe effect, σ8, the galaxy power spectrum Pga1(k) , fluctuations of galaxy counts in spheres of radii ranging from 16/h to 128/h Mpc, Baryon Acoustic Oscillation (BAO) measurements, and h=0.678±0.009, in various combinations, with free spectral index n, and free galaxy bias and galaxy bias slope, we obtain consistent measurements of Σmv. The results depend on h, so we have presented confidence contours in the (Σmv, h) plane. A global fit with h=0.678±0.009 obtains eV, and the amplitude and spectral index of the power spectrum of linear density fluctuations P(k): , and n=1.021±0.075. The fit also returns the galaxy bias b including its scale dependence.展开更多
Several models in noncommutative geometry (NCG) with mild changes to the standard model are introduced to discuss the neutrino mass problem. We use two constraints, Poincaré duality and gauge anomaly free, to dis...Several models in noncommutative geometry (NCG) with mild changes to the standard model are introduced to discuss the neutrino mass problem. We use two constraints, Poincaré duality and gauge anomaly free, to discuss the possibility of containing right-handed neutrinos in them. Our work shows that no model in this paper, with each generation containing a right-handed neutrino, can satisfy these two constraints at the same time. So, to consist with neutrino oscillation experiment results, maybe fundamental changes to the present version of NCG are usually needed to include Dirac massive neutrinos.展开更多
Combining with cosmological constraints we find a most probable value of 17.6 meV for beta decay anti-neutrinos. In passing we note that our expectation for the quadric Higgs self-coupling deviates from standard model...Combining with cosmological constraints we find a most probable value of 17.6 meV for beta decay anti-neutrinos. In passing we note that our expectation for the quadric Higgs self-coupling deviates from standard model expectations by a factor equal to the ud quark mixing matrix element. This matrix element also turns up by its square root in the expected triple self-coupling. We present neutrino mass eigenstates related to the neutron beta decay. In our first scenario we get 15.2 meV for the lowest mass eigenstate, in the second we get 0.917 eV. The latter is to be covered by the KATRIN experiment, while the former comes close to the CRES sensitivity in the Project 8 reach.展开更多
Besides the fact of parity violation in weak interactions,based on evidences from neutrino oscillation and tritium beta decay,a natural conjecture is that neutrinos may be spacelike particles with a tiny proper mass.A...Besides the fact of parity violation in weak interactions,based on evidences from neutrino oscillation and tritium beta decay,a natural conjecture is that neutrinos may be spacelike particles with a tiny proper mass.A Dirac-type equation for spacelike neutrinos is further investigated and its solutions are discussed.This equation can be written in two spinor equations coupled together via nonzero proper mass while respecting maximum parity violation.展开更多
From 21 independent Baryon Acoustic Oscillation (BAO) measurements we obtain the following sum of masses of active Dirac or Majorana neutrinos: , where and . This result may be combined with independent measurements t...From 21 independent Baryon Acoustic Oscillation (BAO) measurements we obtain the following sum of masses of active Dirac or Majorana neutrinos: , where and . This result may be combined with independent measurements that constrain the parameters Σmv, h, and Ωbh2 . For?? and , we obtain at 95% confidence.展开更多
The effects of CP-phases on the three absolute quasi-degenerate Majorana neutrino (QDN) masses are studied with neutrino mass matrices obeying μ – τ symmetry for normal as well as inverted hierarchical mass pattern...The effects of CP-phases on the three absolute quasi-degenerate Majorana neutrino (QDN) masses are studied with neutrino mass matrices obeying μ – τ symmetry for normal as well as inverted hierarchical mass patterns. We have made further investigations on 1) the prediction of solar mixing angle which lies below tri-bimaximal mixing value in consistent with neutrino oscillation observational data, 2) the prediction on absolute neutrino mass parameter (mee) in 0νββ decay, and 3) cosmological bound on the sum of the three absolute neutrino masses . The numerical analysis is carried out through the parameterization of neutrino mass matrices using only two unknown parameters (ε, η) within μ – τ symmetry. The results show the validity of QDN mass models in both normal and inverted hierarchical patterns. These models are far from discrimination and hence not yet ruled out. The results presented in this article are new and have subtle ef- fects in the discrimination of neutrino mass models.展开更多
The recent observational data supports the deviation from Tri-bimaximal (TBM) mixing. Different theories suggest the interdependency among the observational parameters involving the mixing angles. On phenomenological ...The recent observational data supports the deviation from Tri-bimaximal (TBM) mixing. Different theories suggest the interdependency among the observational parameters involving the mixing angles. On phenomenological ground, we try to construct the PMNS matrix, UPMNS with certain analytic structure satisfying spontaneously the unitary condition, in terms of a single observational parameter sinθ13 We hypothesise the three neutrino masses, mi as functions of sinθ13 and then construct the neutrino mass matrix Mv with certain exact and expandable form. We assume the convergence of the model to TBM mixing when θ13 is taken 0. The mass matrix so far obtained can be employed for various applications including the estimation of matter-antimatter asymmetry of the universe.展开更多
In this paper,following the Occam’s razor principle,we have put forward a very simple form of the Dirac neutrino mass matrix M_(D) in the minimal seesaw model with the right-handed neutrino mass matrix being diagonal...In this paper,following the Occam’s razor principle,we have put forward a very simple form of the Dirac neutrino mass matrix M_(D) in the minimal seesaw model with the right-handed neutrino mass matrix being diagonal M_(R)=diag(M_(1),M_(2));it has one texture zero and only contains three real parameters,whose values can be determined from the neutrino oscillation experimental results.Such a model leads to a neutrino mass matrix M_(v)≃-M_(D)M_(R)^(-1)M_(D)^(T)that obeys the TM1 and μ-τ reflection symmetries simultaneously.In this way all the lepton flavor mixing parameters except for θ_(13) are predicted;the value of θ_(12) is predicted by the TM1 symmetry,while those of θ_(23),δ,ρ and σ by the μ-τ reflection symmetry.And the neutrino masses are predicted to be of the NO case with m_(1)=0,for which all three light neutrino masses will be pinned down with the help of the experimental results for the neutrino mass squared differences.For these results,the effective Majorana neutrino mass∣(M_(ν))_(ee)∣that controls the rate of the neutrinoless double beta decay is predicted to be 1.6 or 3.8 meV in the case of σ=0 or π/2.We have also studied the implications of the model for leptogenesis.It turns out that only in the two-flavor leptogenesis regime(which holds in the temperature range 10^(9)-10^(12) GeV)can leptogenesis have a chance to be successful.And a successful leptogenesis can be achieved at M_(1)≃1.2×10^(11) GeV in the case of σ=π/2,but not in the case of σ=0.展开更多
The Standard Model of particle physics involves twelve fundamental fermions, treated as point particles, in four charge states. However, the Standard Model does not explain why only three fermions are in each charge s...The Standard Model of particle physics involves twelve fundamental fermions, treated as point particles, in four charge states. However, the Standard Model does not explain why only three fermions are in each charge state or account for neutrino mass. This holographic analysis treats charged Standard Model fermions as spheres with mass 0.187 g/cm<sup>2</sup> times their surface area, using the proportionality constant in the holographic relation between mass of the observable universe and event horizon radius. The analysis requires three Standard Model fermions per charge state and relates up quark and down quark masses to electron mass. Holographic analysis specifies electron mass, to six significant figures, in terms of fundamental constants α,ℏ,G,Λ and Ω Λ . Treating neutrinos as spheres and equating electron neutrino energy density with cosmic vacuum energy density predicts neutrino masses consistent with experiment.展开更多
In this work,we investigate the constraints on the total neutrino mass in the scenario of vacuum energy interacting with cold dark matter(abbreviated as IACDM)by using the latest cosmological observations.We consider ...In this work,we investigate the constraints on the total neutrino mass in the scenario of vacuum energy interacting with cold dark matter(abbreviated as IACDM)by using the latest cosmological observations.We consider four typical interaction forms,i.e.Q=βHρde,Q=βHρc,Q=βH0ρde,and Q=βH0ρc,in the IACDM scenario.To avoid the large-scale instability problem in interacting dark energy models,we employ the extended parameterized post-Friedmann method for interacting dark energy to calculate the perturbation evolution of dark energy in these models.The observational data used in this work include the cosmic microwave background(CMB)measurements from the Planck 2018 data release,the baryon acoustic oscillation(BAO)data,the type Ia supernovae(SN)observation(Pantheon compilation),and the 2019 local distance ladder measurement of the Hubble constant H0 from the Hubble Space Telescope.We find that,compared with those in the ACDM+∑mv model,the constrains on∑mv are looser in the four IACDM+∑mv models.When considering the three mass hierarchies of neutrinos,the constraints on∑mv are tightest in the degenerate hierarchy case and loosest in the inverted hierarchy case.In addition,in the four IACDM+∑mv models,the values of coupling parameterβare larger using the CMB+BAO+SN+H0 data combination than that using the CMB+BAO+SN data combination,andβ>0 is favored at more than 1σlevel when using CMB+BAO+SN+H0 data combination.The issue of the H0 tension is also discussed in this paper.We find that,compared with the ACDM+∑mv model,the H0 tension can be alleviated in the IACDM+∑mv model to some extent.展开更多
We investigate the constraints on total neutrino mass in the scenario of vacuum energy interacting with cold dark matter. We focus on two typical interaction forms, i.e., Q=βHρc and Q=βHρΛ. To avoid the occurrenc...We investigate the constraints on total neutrino mass in the scenario of vacuum energy interacting with cold dark matter. We focus on two typical interaction forms, i.e., Q=βHρc and Q=βHρΛ. To avoid the occurrence of large-scale instability in interacting dark energy cosmology, we adopt the parameterized post-Friedmann approach to calculate the perturbation evolution of dark energy. We employ observational data, including the Planck cosmic microwave background temperature and polarization data, baryon acoustic oscillation data, a JLA sample of type Ia supernovae observation, direct measurement of the Hubble constant, and redshift space distortion data. We find that, compared with those in the ΛCDM model, much looser constraints onstraints are obtained in the Q=βHρΛ mode mν are obtained in the Q = βHρc model, whereas slightly tighter conl. Consideration of the possible mass hierarchies of neutrinos reveals that the smallest upper limit ofarchy mν appears in the degenerate hierarchy case. By comparing the values of χ~2 min, we find that the normal hiercase is favored over the inverted one. In particular,we find that the difference ?χ22 min ≡χIH;min-χ~2 NH;min〉 2 in the Q = βHρc model. In addition, we find that β = 0 is consistent with the current observations in the Q=βHρc model, and β 〈0 is favored at more than the 1σ level in the Q=βHρΛ model.展开更多
We investigate how the dark energy properties impact the constraints on the total neutrino mass in interacting dark energy(IDE)models. In this study, we focus on two typical interacting dynamical dark energy models, i...We investigate how the dark energy properties impact the constraints on the total neutrino mass in interacting dark energy(IDE)models. In this study, we focus on two typical interacting dynamical dark energy models, i.e., the interacting w cold dark matter(IwCDM) model and the interacting holographic dark energy(IHDE) model. To avoid the large-scale instability problem in IDE models, we apply the parameterized post-Friedmann approach to calculate the perturbation of dark energy. We employ the Planck 2015 cosmic microwave background temperature and polarization data, combined with low-redshift measurements on baryon acoustic oscillation distance scales, type Ia supernovae, and the Hubble constant, to constrain the cosmological parameters. We find that the dark energy properties could influence the constraint limits on the total neutrino mass. Once dynamical dark energy is considered in the IDE models, the upper bounds of ∑mν will be changed. By considering the values of χ^2min , we find that in these IDE models the normal hierarchy case is slightly preferred over the inverted hierarchy case;for example, △χ^2= 2.720 is given in the IHDE+∑mν model. In addition, we also find that in the Iw CDM+∑mν model β = 0 is consistent with current observational data inside the 1σ range, and in the IHDE+∑mν model β > 0 is favored at more than 2σ level.展开更多
We investigate the constraints on the sum of neutrino masses(Σmv) using the most recent cosmological data, which combines the distance measurement from baryonic acoustic oscillation in the extended Baryon Oscillati...We investigate the constraints on the sum of neutrino masses(Σmv) using the most recent cosmological data, which combines the distance measurement from baryonic acoustic oscillation in the extended Baryon Oscillation Spectroscopic Survey DR14 quasar sample with the power spectra of temperature and polarization anisotropies in the cosmic microwave background from the Planck 2015 data release. We also use other low-redshift observations,including the baryonic acoustic oscillation at relatively low redshifts, Type la supernovae, and the local measurement of the Hubble constant. In the standard cosmological constant A cold dark matter plus massive neutrino model,we obtain the 95% upper limit to be Σmv 〈0.129 eV for the degenerate mass hierarchy,Σmv 〈0.159 eV for the normal mass hierarchy, and Σmv 〈0.189 eV for the inverted mass hierarchy. Based on Bayesian evidence, we find that the degenerate hierarchy is positively supported, and the current data combination cannot distinguish between normal and inverted hierarchies. Assuming the degenerate mass hierarchy, we extend our study to non-standard cosmological models including generic dark energy, spatial curvature, and extra relativistic degrees of freedom, but find these models are not favored by the data.展开更多
We extend the colored Zee-Babu model with a gauged U(1)B-L symmetry, and a scalar singlet dark matter (DM) candidate S. The spontaneous breaking of U(1)B-L leaves a residual Z2 symmetry that stabilizes the DM, a...We extend the colored Zee-Babu model with a gauged U(1)B-L symmetry, and a scalar singlet dark matter (DM) candidate S. The spontaneous breaking of U(1)B-L leaves a residual Z2 symmetry that stabilizes the DM, and generates a tiny neutrino mass at the two-loop level with the color seesaw mechanism. After investigating the DM and flavor phenomenology of this model systematically, we further focus on its imprint on two cosmic-ray anomalies: The Fermi-LAT gamma-ray excess at the Galactic Center (GCE), and the PeV ultra-high energy (UHE) neutrino events at the IceCube. We found that the Fermi-LAT GCE spectrum can be well-fitted by DM annihilation into a pair of on-shell singlet Higgs mediators while being compatible with the constraints from the relic density, direct detections, and dwarf spheroidal galaxies, in the Milky Way. Although the UHE neutrino events at the IceCube could be accounted for by the resonance production of a TeV-scale leptoquark, the relevant Yukawa couplings have been severely limited by the current low-energy flavor experiments. We subsequently derive the IceCube limits on the Yukawa couplings by employing its latest six-year data.展开更多
Considering the mass splittings of three active neutrinos,we investigate how the properties of dark energy affect the cosmological constraints on the total neutrino mass∑mv using the latest cosmological observations....Considering the mass splittings of three active neutrinos,we investigate how the properties of dark energy affect the cosmological constraints on the total neutrino mass∑mv using the latest cosmological observations.In this paper,several typical dark energy models,including ACDM,wCDM,CPL,and HDE models,are discussed.In the analysis,we also consider the effects from the neutrino mass hierarchies,i.e.the degenerate hierarchy(DH),the normal hierarchy(NH),and the inverted hierarchy(IH).We employ the current cosmological observations to do the analysis,including the Planck 2018 temperature and polarization power spectra,the baryon acoustic oscillations(BAO),the type Ia supernovae(SNe),and the Hubble constant H0 measurement.In the ACDM+∑mv model,we obtain the upper limits of the neutrino mass∑mv<0.123 eV(DH),∑mv<0.156 eV(NH),and∑mv<0.185 eV(IH)at the 95%C.L.,using the Planck+BAO+SNe data combination.For the wCDM+∑mv model and the CPL+∑mv model,larger upper limits of∑mv are obtained compared to those of the ACDM+∑mv model.The most stringent constraint on the neutrino mass,∑mv<0.080 eV(DH),is derived in the HDE+∑mv model.In addition,we find that the inclusion of the local measurement of the Hubble constant in the data combination leads to tighter constraints on the total neutrino mass in all these dark energy models.展开更多
文摘In this paper, the submicroscopic deterministic concept developed by the author is applied to the problem of the neutrino mass. A particle appears from space considered as a mathematical lattice of primary topological balls, and induces a deformation coat in its surrounding. The principles of the interaction of particles with space and through space between themselves are considered in detail. The approach states that real quarks possess only an integer charge (±e) and when moving they periodically change to the monopole state (⇄g) and hence, canonical particles are dynamic dyons. A neutrino emerges as a squeezed quark when it is in a monopole state, or in other words, the quark monopole state (a bubble in the tessellattice) is transferred to the appropriate lepton monopole state (a speck in the tessellattice). The self-mass (a “rest” mass) for each neutrino flavour is calculated. The calculated value of the self-mass for the electron anti-neutrino is 1.22873978 × 10<sup>-36</sup> kg = 0.68927247 eV/c<sup>2</sup>. The concept of neutrino oscillations is revised, and another postulation is proposed, namely, that the transition from lighter to heavier flavors is due to the inelastic scattering of neutrinos on oncoming scatterers. As a result, the neutrino captures the mass defect, becomes heavier, and therefore the transitions V<sub>e</sub>⟶V<sub>μ</sub> and V<sub>μ</sub>⟶V<sub>τ</sub> occur;thus, the number of light neutrinos decreases in the neutrino flux studied.
文摘We constrain two dynamical dark energy models that are parametrized by the logarithm form of and the oscillating form of . Comparing with the Chevallier-Polarski-Linder (CPL) model, the two parametrizations for dark energy can explore the whole evolution history of the universe properly. Using the current mainstream observational data including the cosmic microwave background data and the baryon acoustic oscillation data as well as the type Ia supernovae data, we perform the X<sup>2</sup> statistic analysis to global fit these models, finding that the logarithm parametrization and the oscillating parameterization are almost as well as the CPL scenario in fitting these data. We make a comparison for the impacts of the dynamical dark energy on the cosmological constraints on the total mass of active neutrinos. We find that the logarithm parametrization and the oscillating parameterization can increase the fitting values of Σm<sub>v</sub>. Looser constraints on Σm<sub>v</sub> are obtained in the logarithm and oscillating models than those derived in the CPL model. Consideration of the possible mass ordering of neutrinos reveals that the most stringent constraint on Σm<sub>v</sub> appears in the degenerate hierarchy case.
文摘This paper aims at solving several open questions in current neutrino physics: the neutrino mass hierarchy, the Dirac CP violating phase, the absolute mass of neutrinos, the nature of neutrinos (Dirac or Majorana), the Majorana matrix and the absolute value of the effective Majorana neutrino mass. In the research presented in this paper, we have shown that the precise definition of the mass splittings between neutrino mass eigenstates, done in the latest analysis of experimental data, can be of crucial importance for defining the nature of neutrino mass hierarchy. The Standard Model has three generations of fundamental matter particles. Three generations of the charged lepton mass show a hierarchical structure: m<sub>τ</sub> > m<sub>μ</sub> > m<sub>e</sub>. Owing to that, there is a belief and it is considered that neutrinos may follow such hierarchical structure. In our calculations, we have also included the latest data obtained, based on the processing of measurement results, which showed that even with such data, obtained results favor the normal neutrino mass hierarchy. As for the individual neutrino mass calculated in this paper, in today’s neutrino physics it is only known that neutrino mass scale is bounded only from above, and both the Dirac and the Majorana character of neutrinos are compatible with all observations. Among some of the questions resolved in this paper, which are related to the properties of neutrinos, a positive answer was also given to the question of whether light neutrinos are self-conjugate particles or not.
文摘In this work the Generalized Special Relativity (GSR) is utilized to estimate masses of some elementary particles such as, neutrinos. These results are found to be in conformity with experimental and theoretical data. The results obtained may explain some physical phenomena, such as, conversion of neutrinos from type to type when solar neutrino reaches the Earth.
文摘We study galaxy distributions with Sloan Digital Sky Survey SDSS DR14 data and with simulations searching for variables that can constrain neutrino masses. To be specific, we consider the scenario of three active neutrino eigenstates with approximately the same mass, so Σmv=3mv. Fitting the predictions of the ΛCDM model to the Sachs-Wolfe effect, σ8, the galaxy power spectrum Pga1(k) , fluctuations of galaxy counts in spheres of radii ranging from 16/h to 128/h Mpc, Baryon Acoustic Oscillation (BAO) measurements, and h=0.678±0.009, in various combinations, with free spectral index n, and free galaxy bias and galaxy bias slope, we obtain consistent measurements of Σmv. The results depend on h, so we have presented confidence contours in the (Σmv, h) plane. A global fit with h=0.678±0.009 obtains eV, and the amplitude and spectral index of the power spectrum of linear density fluctuations P(k): , and n=1.021±0.075. The fit also returns the galaxy bias b including its scale dependence.
文摘Several models in noncommutative geometry (NCG) with mild changes to the standard model are introduced to discuss the neutrino mass problem. We use two constraints, Poincaré duality and gauge anomaly free, to discuss the possibility of containing right-handed neutrinos in them. Our work shows that no model in this paper, with each generation containing a right-handed neutrino, can satisfy these two constraints at the same time. So, to consist with neutrino oscillation experiment results, maybe fundamental changes to the present version of NCG are usually needed to include Dirac massive neutrinos.
文摘Combining with cosmological constraints we find a most probable value of 17.6 meV for beta decay anti-neutrinos. In passing we note that our expectation for the quadric Higgs self-coupling deviates from standard model expectations by a factor equal to the ud quark mixing matrix element. This matrix element also turns up by its square root in the expected triple self-coupling. We present neutrino mass eigenstates related to the neutron beta decay. In our first scenario we get 15.2 meV for the lowest mass eigenstate, in the second we get 0.917 eV. The latter is to be covered by the KATRIN experiment, while the former comes close to the CRES sensitivity in the Project 8 reach.
文摘Besides the fact of parity violation in weak interactions,based on evidences from neutrino oscillation and tritium beta decay,a natural conjecture is that neutrinos may be spacelike particles with a tiny proper mass.A Dirac-type equation for spacelike neutrinos is further investigated and its solutions are discussed.This equation can be written in two spinor equations coupled together via nonzero proper mass while respecting maximum parity violation.
文摘From 21 independent Baryon Acoustic Oscillation (BAO) measurements we obtain the following sum of masses of active Dirac or Majorana neutrinos: , where and . This result may be combined with independent measurements that constrain the parameters Σmv, h, and Ωbh2 . For?? and , we obtain at 95% confidence.
文摘The effects of CP-phases on the three absolute quasi-degenerate Majorana neutrino (QDN) masses are studied with neutrino mass matrices obeying μ – τ symmetry for normal as well as inverted hierarchical mass patterns. We have made further investigations on 1) the prediction of solar mixing angle which lies below tri-bimaximal mixing value in consistent with neutrino oscillation observational data, 2) the prediction on absolute neutrino mass parameter (mee) in 0νββ decay, and 3) cosmological bound on the sum of the three absolute neutrino masses . The numerical analysis is carried out through the parameterization of neutrino mass matrices using only two unknown parameters (ε, η) within μ – τ symmetry. The results show the validity of QDN mass models in both normal and inverted hierarchical patterns. These models are far from discrimination and hence not yet ruled out. The results presented in this article are new and have subtle ef- fects in the discrimination of neutrino mass models.
文摘The recent observational data supports the deviation from Tri-bimaximal (TBM) mixing. Different theories suggest the interdependency among the observational parameters involving the mixing angles. On phenomenological ground, we try to construct the PMNS matrix, UPMNS with certain analytic structure satisfying spontaneously the unitary condition, in terms of a single observational parameter sinθ13 We hypothesise the three neutrino masses, mi as functions of sinθ13 and then construct the neutrino mass matrix Mv with certain exact and expandable form. We assume the convergence of the model to TBM mixing when θ13 is taken 0. The mass matrix so far obtained can be employed for various applications including the estimation of matter-antimatter asymmetry of the universe.
基金supported in part by the National Natural Science Foundation of China under Grant Nos.11605081,12142507 and 12147214the Natural Science Foundation of the Liaoning Scientific Committee under Grant No.2022MS-314
文摘In this paper,following the Occam’s razor principle,we have put forward a very simple form of the Dirac neutrino mass matrix M_(D) in the minimal seesaw model with the right-handed neutrino mass matrix being diagonal M_(R)=diag(M_(1),M_(2));it has one texture zero and only contains three real parameters,whose values can be determined from the neutrino oscillation experimental results.Such a model leads to a neutrino mass matrix M_(v)≃-M_(D)M_(R)^(-1)M_(D)^(T)that obeys the TM1 and μ-τ reflection symmetries simultaneously.In this way all the lepton flavor mixing parameters except for θ_(13) are predicted;the value of θ_(12) is predicted by the TM1 symmetry,while those of θ_(23),δ,ρ and σ by the μ-τ reflection symmetry.And the neutrino masses are predicted to be of the NO case with m_(1)=0,for which all three light neutrino masses will be pinned down with the help of the experimental results for the neutrino mass squared differences.For these results,the effective Majorana neutrino mass∣(M_(ν))_(ee)∣that controls the rate of the neutrinoless double beta decay is predicted to be 1.6 or 3.8 meV in the case of σ=0 or π/2.We have also studied the implications of the model for leptogenesis.It turns out that only in the two-flavor leptogenesis regime(which holds in the temperature range 10^(9)-10^(12) GeV)can leptogenesis have a chance to be successful.And a successful leptogenesis can be achieved at M_(1)≃1.2×10^(11) GeV in the case of σ=π/2,but not in the case of σ=0.
文摘The Standard Model of particle physics involves twelve fundamental fermions, treated as point particles, in four charge states. However, the Standard Model does not explain why only three fermions are in each charge state or account for neutrino mass. This holographic analysis treats charged Standard Model fermions as spheres with mass 0.187 g/cm<sup>2</sup> times their surface area, using the proportionality constant in the holographic relation between mass of the observable universe and event horizon radius. The analysis requires three Standard Model fermions per charge state and relates up quark and down quark masses to electron mass. Holographic analysis specifies electron mass, to six significant figures, in terms of fundamental constants α,ℏ,G,Λ and Ω Λ . Treating neutrinos as spheres and equating electron neutrino energy density with cosmic vacuum energy density predicts neutrino masses consistent with experiment.
基金supported by the National Natural Science Foundation of China(Grant Nos.11975072,11875102,11835009,and 11690021)the Liaoning Revitalization Talents Program(Grant No.XLYC1905011)+1 种基金the Fundamental Research Funds for the Central Universities(Grant No.N2005030)the Top-Notch Young Talents Program of China(W02070050)。
文摘In this work,we investigate the constraints on the total neutrino mass in the scenario of vacuum energy interacting with cold dark matter(abbreviated as IACDM)by using the latest cosmological observations.We consider four typical interaction forms,i.e.Q=βHρde,Q=βHρc,Q=βH0ρde,and Q=βH0ρc,in the IACDM scenario.To avoid the large-scale instability problem in interacting dark energy models,we employ the extended parameterized post-Friedmann method for interacting dark energy to calculate the perturbation evolution of dark energy in these models.The observational data used in this work include the cosmic microwave background(CMB)measurements from the Planck 2018 data release,the baryon acoustic oscillation(BAO)data,the type Ia supernovae(SN)observation(Pantheon compilation),and the 2019 local distance ladder measurement of the Hubble constant H0 from the Hubble Space Telescope.We find that,compared with those in the ACDM+∑mv model,the constrains on∑mv are looser in the four IACDM+∑mv models.When considering the three mass hierarchies of neutrinos,the constraints on∑mv are tightest in the degenerate hierarchy case and loosest in the inverted hierarchy case.In addition,in the four IACDM+∑mv models,the values of coupling parameterβare larger using the CMB+BAO+SN+H0 data combination than that using the CMB+BAO+SN data combination,andβ>0 is favored at more than 1σlevel when using CMB+BAO+SN+H0 data combination.The issue of the H0 tension is also discussed in this paper.We find that,compared with the ACDM+∑mv model,the H0 tension can be alleviated in the IACDM+∑mv model to some extent.
基金Supported by National Natural Science Foundation of China(11522540,11690021)the Top-Notch Young Talents Program of Chinathe Provincial Department of Education of Liaoning(L2012087)
文摘We investigate the constraints on total neutrino mass in the scenario of vacuum energy interacting with cold dark matter. We focus on two typical interaction forms, i.e., Q=βHρc and Q=βHρΛ. To avoid the occurrence of large-scale instability in interacting dark energy cosmology, we adopt the parameterized post-Friedmann approach to calculate the perturbation evolution of dark energy. We employ observational data, including the Planck cosmic microwave background temperature and polarization data, baryon acoustic oscillation data, a JLA sample of type Ia supernovae observation, direct measurement of the Hubble constant, and redshift space distortion data. We find that, compared with those in the ΛCDM model, much looser constraints onstraints are obtained in the Q=βHρΛ mode mν are obtained in the Q = βHρc model, whereas slightly tighter conl. Consideration of the possible mass hierarchies of neutrinos reveals that the smallest upper limit ofarchy mν appears in the degenerate hierarchy case. By comparing the values of χ~2 min, we find that the normal hiercase is favored over the inverted one. In particular,we find that the difference ?χ22 min ≡χIH;min-χ~2 NH;min〉 2 in the Q = βHρc model. In addition, we find that β = 0 is consistent with the current observations in the Q=βHρc model, and β 〈0 is favored at more than the 1σ level in the Q=βHρΛ model.
基金supported by the National Natural Science Foundation of China(Grant Nos.11875102,11835009,11522540,11690021,and61603265)the National Program for Support of Top-Notch Young ProfessionalsDoctoral Research Project of Shenyang Normal University(Grant Nos.BS201844,and BS201702)
文摘We investigate how the dark energy properties impact the constraints on the total neutrino mass in interacting dark energy(IDE)models. In this study, we focus on two typical interacting dynamical dark energy models, i.e., the interacting w cold dark matter(IwCDM) model and the interacting holographic dark energy(IHDE) model. To avoid the large-scale instability problem in IDE models, we apply the parameterized post-Friedmann approach to calculate the perturbation of dark energy. We employ the Planck 2015 cosmic microwave background temperature and polarization data, combined with low-redshift measurements on baryon acoustic oscillation distance scales, type Ia supernovae, and the Hubble constant, to constrain the cosmological parameters. We find that the dark energy properties could influence the constraint limits on the total neutrino mass. Once dynamical dark energy is considered in the IDE models, the upper bounds of ∑mν will be changed. By considering the values of χ^2min , we find that in these IDE models the normal hierarchy case is slightly preferred over the inverted hierarchy case;for example, △χ^2= 2.720 is given in the IHDE+∑mν model. In addition, we also find that in the Iw CDM+∑mν model β = 0 is consistent with current observational data inside the 1σ range, and in the IHDE+∑mν model β > 0 is favored at more than 2σ level.
基金Supported by a grant from the Research Grant Council of the Hong Kong Special Administrative Region,China(14301214)Supported by the National Natural Science Foundation of China(11505018)the Chongqing Science and Technology Plan Project(Cstc2015jvyj40031)
文摘We investigate the constraints on the sum of neutrino masses(Σmv) using the most recent cosmological data, which combines the distance measurement from baryonic acoustic oscillation in the extended Baryon Oscillation Spectroscopic Survey DR14 quasar sample with the power spectra of temperature and polarization anisotropies in the cosmic microwave background from the Planck 2015 data release. We also use other low-redshift observations,including the baryonic acoustic oscillation at relatively low redshifts, Type la supernovae, and the local measurement of the Hubble constant. In the standard cosmological constant A cold dark matter plus massive neutrino model,we obtain the 95% upper limit to be Σmv 〈0.129 eV for the degenerate mass hierarchy,Σmv 〈0.159 eV for the normal mass hierarchy, and Σmv 〈0.189 eV for the inverted mass hierarchy. Based on Bayesian evidence, we find that the degenerate hierarchy is positively supported, and the current data combination cannot distinguish between normal and inverted hierarchies. Assuming the degenerate mass hierarchy, we extend our study to non-standard cosmological models including generic dark energy, spatial curvature, and extra relativistic degrees of freedom, but find these models are not favored by the data.
基金Supported by the NSFC(11575089,11025525)the National Key Research and Development Program of China(2017YFA0402200)the CAS Center for Excellence in Particle Physics(CCEPP)
文摘We extend the colored Zee-Babu model with a gauged U(1)B-L symmetry, and a scalar singlet dark matter (DM) candidate S. The spontaneous breaking of U(1)B-L leaves a residual Z2 symmetry that stabilizes the DM, and generates a tiny neutrino mass at the two-loop level with the color seesaw mechanism. After investigating the DM and flavor phenomenology of this model systematically, we further focus on its imprint on two cosmic-ray anomalies: The Fermi-LAT gamma-ray excess at the Galactic Center (GCE), and the PeV ultra-high energy (UHE) neutrino events at the IceCube. We found that the Fermi-LAT GCE spectrum can be well-fitted by DM annihilation into a pair of on-shell singlet Higgs mediators while being compatible with the constraints from the relic density, direct detections, and dwarf spheroidal galaxies, in the Milky Way. Although the UHE neutrino events at the IceCube could be accounted for by the resonance production of a TeV-scale leptoquark, the relevant Yukawa couplings have been severely limited by the current low-energy flavor experiments. We subsequently derive the IceCube limits on the Yukawa couplings by employing its latest six-year data.
基金supported by the National Natural Science Foundation of China(Grant Nos.11975072,11875102,11835009,and 11690021)the Liaoning Revitalization Talents Program(Grant No.XLYC1905011)+1 种基金the Fundamental Research Funds for the Central Universities(Grant No.N2005030)the Top-Notch Young Talents Program of China(Grant No.W02070050)。
文摘Considering the mass splittings of three active neutrinos,we investigate how the properties of dark energy affect the cosmological constraints on the total neutrino mass∑mv using the latest cosmological observations.In this paper,several typical dark energy models,including ACDM,wCDM,CPL,and HDE models,are discussed.In the analysis,we also consider the effects from the neutrino mass hierarchies,i.e.the degenerate hierarchy(DH),the normal hierarchy(NH),and the inverted hierarchy(IH).We employ the current cosmological observations to do the analysis,including the Planck 2018 temperature and polarization power spectra,the baryon acoustic oscillations(BAO),the type Ia supernovae(SNe),and the Hubble constant H0 measurement.In the ACDM+∑mv model,we obtain the upper limits of the neutrino mass∑mv<0.123 eV(DH),∑mv<0.156 eV(NH),and∑mv<0.185 eV(IH)at the 95%C.L.,using the Planck+BAO+SNe data combination.For the wCDM+∑mv model and the CPL+∑mv model,larger upper limits of∑mv are obtained compared to those of the ACDM+∑mv model.The most stringent constraint on the neutrino mass,∑mv<0.080 eV(DH),is derived in the HDE+∑mv model.In addition,we find that the inclusion of the local measurement of the Hubble constant in the data combination leads to tighter constraints on the total neutrino mass in all these dark energy models.