Neutrino mass and New physics

Smirnov, A. Yu.

doi:10.1088/1742-6596/53/1/003

Cited by 9 publications

(7 citation statements)

References 178 publications

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“…[71] found that with min = 5, S4 experiments could constrain m ν to ±15 meV (68% confidence) when analyzed in conjunction with Planck polarization and DESI data; with min = 50, the error degrades to ±19 meV. Now, neutrino oscillation measurements constrain m ν to have a minimum value of 60 meV [73][74][75][76]. If we take this to be our fiducial value for m ν , going from min = 5 to min = 50 then represents a degradation from a ∼ 4σ to a ∼ 3σ detection.…”

Section: Planckmentioning

confidence: 99%

Eliminating the optical depth nuisance from the CMB with 21 cm cosmology

et al. 2016

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Amongst standard model parameters that are constrained by cosmic microwave background (CMB) observations, the optical depth τ stands out as a nuisance parameter. While τ provides some crude limits on reionization, it also degrades constraints on other cosmological parameters. Here we explore how 21 cm cosmology-as a direct probe of reionization-can be used to independently predict τ in an effort to improve CMB parameter constraints. We develop two complementary schemes for doing so. The first uses 21 cm power spectrum observations in conjunction with semianalytic simulations to predict τ . The other uses global 21 cm measurements to directly constrain low redshift (post-reheating) contributions to τ in a relatively model-independent way. Forecasting the performance of the upcoming Hydrogen Epoch of Reionization Array, we find that significant reductions in the errors on τ can be achieved. These results are particularly effective at breaking the CMB degeneracy between τ and the amplitude of the primordial fluctuation spectrum As, with errors on ln(10 10 As) reduced by up to a factor of four. Stage 4 CMB constraints on the neutrino mass sum are also improved, with errors potentially reduced to 12 meV regardless of whether CMB experiments can precisely measure the reionization bump in polarization power spectra. Observations of the 21 cm line are therefore capable of improving not only our understanding of reionization astrophysics, but also of cosmology in general.PACS numbers: 95.75.Pq,98.80.Es

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Section: Planckmentioning

confidence: 99%

Eliminating the optical depth nuisance from the CMB with 21 cm cosmology

et al. 2016

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“…The neutrino sector is still poorly understood and the mechanism that gives rise to their mass is unknown. There are thought to be three active neutrino species, with mass differences measured through solar, atmospheric, reactor, and accelerator neutrino oscillation experiments (for reviews see, e.g., Gonzalez-Garcia and Nir [1], Maltoni et al [2], Smirnov [3], and Feldman et al [4]). The results imply a minimum total mass of 60 meV in a normal hierarchy with two lighter neutrinos and one heavier neutrino, or 100 meV in an inverted hierarchy with two massive neutrinos.…”

Section: Introductionmentioning

confidence: 99%

Towards a cosmological neutrino mass detection

et al. 2015

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Future cosmological measurements should enable the sum of neutrino masses to be determined indirectly through their effects on the expansion rate of the Universe and the clustering of matter. We consider prospects for the gravitationally lensed cosmic microwave background (CMB) anisotropies and baryon acoustic oscillations (BAOs) in the galaxy distribution, examining how the projected uncertainty of ≈15 meV on the neutrino mass sum (a 4σ detection of the minimal mass) might be reached over the next decade. The current 1σ uncertainty of ≈103 meV (Planck-2015 þ BAO-15) will be improved by upcoming "Stage-3" (S3) CMB experiments (S3 þ BAO-15∶ 44 meV), then upcoming BAO measurements (S3 þ DESI∶ 22 meV), and planned next-generation "Stage 4" (S4) CMB experiments (S4 þ DESI∶ 15-19 meV, depending on angular range). An improved optical depth measurement is important: the projected neutrino mass uncertainty increases to 26 meV if S4 is limited to l > 20 and combined with current large-scale polarization data. Looking beyond ΛCDM, including curvature uncertainty increases the forecast mass error by ≈50% for S4 þ DESI, and more than doubles the error with a two-parameter dark-energy equation of state. Complementary low-redshift probes including galaxy lensing will play a role in distinguishing between massive neutrinos and a departure from a w ¼ −1, flat geometry.

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“…The generic properties of mass textures of quarks and leptons derived in the standard model and in supersymmetric models with a Higgs sector with nontrivial flavours and an S 3 flavour symmetry have been discussed in [45,46]. Recent flavour symmetry models are reviewed in [47,48,49,50], see also the references therein.…”

Section: Introductionmentioning

confidence: 99%

Lepton masses, mixings, and flavor-changing neutral currents in a minimalS3-invariant extension of the standard model

2007

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The mass matrices of the charged leptons and neutrinos, previously derived in a minimal S3-invariant extension of the Standard Model, were reparametrized in terms of their eigenvalues. We obtained explicit, analytical expressions for all entries in the neutrino mixing matrix, VP M NS , the neutrino mixing angles and the Majorana phases as functions of the masses of charged leptons and neutrinos in excellent agreement with the latest experimental values. The resulting VP M NS matrix is very close to the tri-bimaximal form of the neutrino mixing matrix. We also derived explicit analytical expressions for the matrices of the Yukawa couplings and computed the branching ratios of some selected flavour changing neutral current processes as functions of the masses of the charged leptons and the neutral Higgs bosons. We find that the S3 × Z2 flavour symmetry and the strong mass hierarchy of the charged leptons strongly suppress the FCNC processes in the leptonic sector well below the present experimental upper bounds by many orders of magnitude.

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Neutrino mass and New physics

Cited by 9 publications

References 178 publications

Eliminating the optical depth nuisance from the CMB with 21 cm cosmology

Eliminating the optical depth nuisance from the CMB with 21 cm cosmology

Towards a cosmological neutrino mass detection

Lepton masses, mixings, and flavor-changing neutral currents in a minimalS3-invariant extension of the standard model

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