4,389 research outputs found

    Deviation from Bimaximal Mixing and Leptonic CP Phases in S4S_4 Family Symmetry and Generalized CP

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    The lepton flavor mixing matrix having one row or one column in common with the bimaximal mixing up to permutations is still compatible with the present neutrino oscillation data. We provide a thorough exploration of generating such a mixing matrix from S4S_4 family symmetry and generalized CP symmetry HCPH_{CP}. Supposing that S4HCPS_4\rtimes H_{CP} is broken down to Z2ST2SU×HCPνZ^{ST^2SU}_2\times H^{\nu}_{CP} in the neutrino sector and Z4TST2UHCPlZ^{TST^{2}U}_4\rtimes H^{l}_{CP} in the charged lepton sector, one column of the PMNS matrix would be of the form (1/2,1/2,1/2)T\left(1/2, 1/\sqrt{2}, 1/2\right)^{T} up to permutations, both Dirac CP phase and Majorana CP phases are trivial in order to accommodate the observed lepton mixing angles. The phenomenological implications of the remnant symmetry K4(TST2,T2U)HCPνK^{(TST^2, T^2U)}_4\rtimes H^{\nu}_{CP} in the neutrino sector and Z2SU×HCPlZ^{SU}_{2}\times H^{l}_{CP} in the charged lepton sector are studied. One row of PMNS matrix is determined to be (1/2,1/2,i/2)\left(1/2, 1/2, -i/\sqrt{2}\right), and all the three leptonic CP phases can only be trivial to fit the measured values of the mixing angles. Two models based on S4S_4 family symmetry and generalized CP are constructed to implement these model independent predictions enforced by remnant symmetry. The correct mass hierarchy among the charged leptons is achieved. The vacuum alignment and higher order corrections are discussed.Comment: 44 pages, 7 figure

    Tri-Direct CP in the Littlest Seesaw Playground

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    We discuss spontaneously broken CP symmetry in two right-handed neutrino models based on the idea of having a {\it different residual flavour symmetry}, together with a {\it different residual CP symmetry}, associated with each of the two right-handed neutrinos. The charged lepton sector also has a {\it different residual flavour symmetry}. In such a {\it tri-direct CP approach}, we show that the combination of the three residual flavour and two residual CP symmetries provides a new way of fixing the parameters. To illustrate the approach, we revisit the Littlest Seesaw (LSS) model based on S4S_4 and then propose new variants which have not so far appeared in the literature, with different predictions for each variant. We analyse numerically the predictions of the new variants, and then propose an explicit model which can realise one of the successful benchmark points, based on the atmospheric flavon vacuum alignment (1,ω2,ω)(1, \omega^2 , \omega) and the solar flavon vacuum alignment (1,7/2,7/2)(1, -7/2, -7/2 ).Comment: 31 pages, 4 figure

    Toward a unified interpretation of quark and lepton mixing from flavor and CP symmetries

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    We discussed the scenario that a discrete flavor group combined with CP symmetry is broken to Z2×CPZ_2\times CP in both neutrino and charged lepton sectors. All lepton mixing angles and CP violation phases are predicted to depend on two free parameters θl\theta_{l} and θν\theta_{\nu} varying in the range of [0,π)[0, \pi). As an example, we comprehensively study the lepton mixing patterns which can be derived from the flavor group Δ(6n2)\Delta(6n^2) and CP symmetry. Three kinds of phenomenologically viable lepton mixing matrices are obtained up to row and column permutations. We further extend this approach to the quark sector. The precisely measured quark mixing angles and CP invariant can be accommodated for certain values of the free parameters θu\theta_{u} and θd\theta_{d}. A simultaneous description of quark and lepton flavor mixing structures can be achieved from a common flavor group Δ(6n2)\Delta(6n^2) and CP, and accordingly the smallest value of the group index nn is n=7n=7.Comment: 40 pages, 8 figure

    Golden Littlest Seesaw

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    We propose and analyse a new class of Littlest Seesaw models, with two right-handed neutrinos in their diagonal mass basis, based on preserving the first column of the Golden Ratio mixing matrix. We perform an exhaustive analysis of all possible remnant symmetries of the group A5A_5 which can be used to enforce various vacuum alignments for the flavon controlling solar mixing, for two simple cases of the atmospheric flavon vacuum alignment. The solar and atmospheric flavon vacuum alignments are enforced by {\em different} remnant symmetries. We examine the phenomenological viability of each of the possible Littlest Seesaw alignments in A5A_5, which preserve the first column of the Golden ratio mixing matrix, using figures and extensive tables of benchmark points and comparing our predictions to a recent global analysis of neutrino data. We also repeat the analysis for an alternative form of Golden Ratio mixing matrix.Comment: 32 pages, 7 figure

    Nonlinear system identification and control using state transition algorithm

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    By transforming identification and control for nonlinear system into optimization problems, a novel optimization method named state transition algorithm (STA) is introduced to solve the problems. In the proposed STA, a solution to a optimization problem is considered as a state, and the updating of a solution equates to a state transition, which makes it easy to understand and convenient to implement. First, the STA is applied to identify the optimal parameters of the estimated system with previously known structure. With the accurate estimated model, an off-line PID controller is then designed optimally by using the STA as well. Experimental results have demonstrated the validity of the methodology, and comparisons to STA with other optimization algorithms have testified that STA is a promising alternative method for system identification and control due to its stronger search ability, faster convergence rate and more stable performance.Comment: 20 pages, 18 figure

    Mutation of SLC35D3 causes metabolic syndrome by impairing dopamine signaling in striatal D1 neurons

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    We thank Dr. Ya-Qin Feng from Shanxi Medical University, Dr. Tian-Yun Gao from Nanjing University and Dr. Yan-Hong Xue from Institute of Biophysics (CAS) for technical assistance in this study. We are very thankful to Drs. Richard T. Swank and Xiao-Jiang Li for their critical reading of this manuscript and invaluable advice. Funding: This work was partially supported by grants from National Basic Research Program of China (2013CB530605; 2014CB942803), from National Natural Science Foundation of China 1230046; 31071252; 81101182) and from Chinese Academy of Sciences (KSCX2-EW-R-05, KJZD-EW-L08). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Peer reviewedPublisher PD
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