883 research outputs found

    Suppressing Proton Decay by Cancellation in S_4 Flavor Symmetric Extra U(1) Model

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    We consider proton stability based on E_6 inspired extra U(1) model with S_4 flavor symmetry. In this model, a long life time of proton is realized by the flavor symmetry. One of the interesting effects of flavor symmetry is that the proton decay widths of p -> mu^+, X are suppressed by cancellation. This suppression mechanism is important in the case that Yukawa coupling constants are hierarchical. Our model predicts p -> e^+, K^0 has larger decay width than that of p -> mu^+, K^0.Comment: 16 pages, 5 tables, and 1 figure; version accepted for publication in Progress of Theoretical Physics. arXiv admin note: text overlap with arXiv:1111.109

    Cancellation Mechanism of FCNCs in S_4 x Z_2 Flavor Symmetric Extra U(1) Model

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    We propose a E_6 inspired supersymmetric model with a non-Abelian discrete flavor symmetry; SU(3)_c x SU(2)_W x U(1)_Y x U(1)_X x S_4 x Z_2. In our scenario, the additional abelian gauge symmetry; U(1)_X, not only solves the mu-problem in the minimal Supersymmetric Standard Model(MSSM), but also requires new exotic fields which play an important role in solving flavor puzzles. If our exotic quarks can be embedded into a S_4 triplet, which corresponds to the number of the generation, one finds that dangerous proton decay can be well-suppressed. Hence, it might be expected that the generation structure for lepton and quark in the SM(Standard Model) can be understood as a new system in order to stabilize the proton in a supersymemtric standard model (SUSY). Moreover, due to the nature of the discrete non-Abelian symmetry itself, Yukawa coupling constants of our model are drastically reduced. In our previous work, we actually have found much success. However, we also have to solve Higgs mediated FCNC at tree level, as is often the case with such extended Higgs models. In this paper, we propose a promising mechanism which could make cancellation between Higgs and SUSY contributions.Comment: 19 pages, 2 tables, no figures. Title is slightly changed and minor parts are modifie

    Radiative symmetry breaking and Higgs mass bound in the NMSSM

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    We study the upper mass bound of the lightest neutral Higgs scalar in the NMSSM using the RGE analysis. We require the successful occurence of the electroweak radiative symmetry breaking to restrict the parameter space. As a result the upper mass bound mh0m_{h^0} is largely restricted compared with the one estimated without imposing this condition. We point out some features of mh0m_{h^0} related to the initial value of hth_t and discuss why the models with more extra matters 5+5ˉ{\bf 5}+\bar{\bf 5} of SU(5) could bring the larger maximum value of mh0m_{h^0}.Comment: 8 pages, latex, 4 eps-figure

    Two Component Dark Matters in S_4 x Z_2 Flavor Symmetric Extra U(1) Model

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    We study cosmic-ray anomaly observed by PAMELA based on E_6 inspired extra U(1) model with S_4 x Z_2 flavor symmetry. In our model, the lightest flavon has very long lifetime of O(10^{18)) second which is longer than the age of the universe, but not long enough to explain the PAMELA result ~ O(10^{26}) sec. Such a situation could be avoidable by considering that the flavon is not the dominant component of dark matters and the dominant one is the lightest neutralino. With appropriate parameter set, density parameter of dark matter and over-abundance of positron flux in cosmic-ray are realized at the same time. There is interesting correlation between spectrum of positron flux and V_{MNS}. No excess of anti-proton in cosmic-ray suggests that sfermions are heavier than 4 TeV and the masses of the light Higgs bosons are degenerated.Comment: 22 pages, 4 figures, 2 tables; version accepted for publication in Progress of Theoretical Physic

    Asynchronous Demodulation Method for Four SSB arranged on Frequency Axis in Mobile Radio Path using Hilbert Transform

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    In this paper, an asynchronous demodulation method for a four-single sideband (SSB) signal arranged on the frequency axis is developed to support burst mode transmission in a mobile radio path and to achieve greater data throughputs. When a reduced pilot carrier is placed at the center of the 4-SSB signal, it is guarded by lower and upper sidebands, that is, this scheme is classified into a tone-in-band (TIB) system. Digital signal processing (DSP) processors are useful for implementing a Hilbert transform. However, we have for a long time neglected introducing it into the demodulation process of SSB signals

    Tonality tunes the statistical characteristics in music: Computational approaches on statistical learning

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    Statistical learning is a learning mechanism based on transition probability in sequences such as music and language. Recent computational and neurophysiological studies suggest that the statistical learning contributes to production, action, and musical creativity as well as prediction and perception. The present study investigated how statistical structure interacts with tonalities in music based on various-order statistical models. To verify this in all 24 major and minor keys, the transition probabilities of the sequences containing the highest pitches in Bach’s Well-Tempered Clavier, which is a collection of two series (No. 1 and No. 2) of preludes and fugues in all of the 24 major and minor keys, were calculated based on nth-order Markov models. The transition probabilities of each sequence were compared among tonalities (major and minor), two series (No. 1 and No. 2), and music types (prelude and fugue). The differences in statistical characteristics between major and minor keys were detected in lower- but not higher-order models. The results also showed that statistical knowledge in music might be modulated by tonalities and composition periods. Furthermore, the principal component analysis detected the shared components of related keys, suggesting that the tonalities modulate statistical characteristics in music. The present study may suggest that there are at least two types of statistical knowledge in music that are interdependent on and independent of tonality, respectively

    S_4 x Z_2 Flavor Symmetry in Supersymmetric Extra U(1) Model

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    We propose a E_6 inspired supersymmetric model with a non-Abelian discrete flavor symmetry (S_4 group); that is, SU(3)_c x SU(2)_W x U(1)_Y x U(1)_X x S_4 x Z_2. In our scenario, the additional abelian gauge symmetry; U(1)_X, not only solves the mu-problem in the minimal Supersymmetric Standard Model(MSSM), but also requires new exotic fields which play an important role in solving flavor puzzles. If our exotic quarks can be embedded into a S_4 triplet, which corresponds to the number of the generation, one finds that dangerous proton decay can be well-suppressed. Hence, it might be expected that the generation structure for lepton and quark in the SM(Standard Model) can be understood as a new system in order to stabilize the proton in a supersymemtric standard model (SUSY). Moreover, due to the nature of the discrete non-Abelian symmetry itself, Yukawa coupling constants of our model are drastically reduced. In our paper, we show two predictive examples of the models for quark sector and lepton sector, respectively.Comment: 14 pages, 4 tables. Flavon sector and references are added. Sentences are modifie

    Concurrent statistical learning of ignored and attended sound sequences: An MEG study

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    In an auditory environment, humans are frequently exposed to overlapping sound sequences such as those made by human voices and musical instruments, and we can acquire information embedded in these sequences via attentional and nonattentional accesses. Whether the knowledge acquired by attentional accesses interacts with that acquired by nonattentional accesses is unknown, however. The present study examined how the statistical learning of two overlapping sound sequences is reflected in neurophysiological and behavioural responses, and how the learning effects are modulated by attention to each sequence. Statistical learning in this experimental paradigm was reflected in a neuromagnetic response predominantly in the right hemisphere, and the learning effects were not retained when attention to the tone streams was switched during the learning session. These results suggest that attentional and nonattentional learning scarcely interact with each other, and that there may be a specific system for nonattentional learning, which is independent of attentional learning
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