647 research outputs found

    Correct Effective Potential of Supersymmetric Yang-Mills Theory on M^4\times S^1

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    We study an N=1{\cal N}=1 supersymmetric Yang-Mills theory defined on M4×S1M^4\times S^1. The vacuum expectation values for adjoint scalar field in vector multiplet, though important, has been overlooked in evaluating one-loop effective potential of the theory. We correctly take the vacuum expectation values into account in addition to the Wilson line phases to give an expression for the effective potential, and gauge symmetry breaking is discussed. In evaluating the potential, we employ the Scherk-Schwarz mechanism and introduce bare mass for gaugino in order to break supersymmetry. We also obtain masses for the scalars, the adjoint scalar, and the component gauge field for the S1S^1 direction in case of the SU(2) gauge group. We observe that large supersymmetry breaking gives larger mass for the scalar. This analysis is easily applied to the M4×S1/Z2M^4\times S^1/Z_2 case.Comment: 12 pages, 1 figur

    Discovery of H alpha absorption in the unusual broad absorption line quasar SDSS J083942.11+380526.3

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    We discovered an H alpha absorption in a broad H alpha emission line of an unusual broad absorption line quasar, SDSS J083942.11+380526.3 at z=2.318, by near-infrared spectroscopy with the Cooled Infrared Spectrograph and Camera for OHS (CISCO) on the Subaru telescope. The Presence of non-stellar H alpha absorption is known only in the Seyfert galaxy NGC 4151 to date, thus our discovery is the first case for quasars. The H alpha absorption line is blueshifted by 520 km/s relative to the H alpha emission line, and its redshift almost coincides with those of UV low-ionization metal absorption lines. The width of the H alpha absorption (~ 340 km/s) is similar to those of the UV low-ionization absorption lines. These facts suggest that the H alpha and the low-ionization metal absorption lines are produced by the same low-ionization gas which has a substantial amount of neutral gas. The column density of the neutral hydrogen is estimated to be ~ 10^18 cm^-2 by assuming a gas temperature of 10,000 K from the analysis of the curve of growth. The continuum spectrum is reproduced by a reddened (E(B-V) ~ 0.15 mag for the SMC-like reddening law) composite quasar spectrum. Furthermore, the UV spectrum of SDSS J083942.11+380526.3 shows a remarkable similarity to that of NGC 4151 in its low state, suggesting the physical condition of the absorber in SDSS J083942.11+380526.3 is similar to that of NGC 4151 in the low state. As proposed for NGC 4151, SDSS J083942.11+380526.3 may be also seen through the close direction of the surface of the obscuring torus.Comment: Accepted for publication in Ap

    Grand Unification of Flavor Mixings

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    An origin of flavor mixings in quark and lepton sectors is still a mystery, and a structure of the flavor mixings in lepton sector seems completely different from that of quark sector. In this letter, we point out that the flavor mixing angles in quark and lepton sectors could be unified at a high energy scale, when neutrinos are degenerate. It means that a minimal flavor violation at a high energy scale can induce a rich variety of flavor mixings in quark and lepton sectors at a low energy scale through quantum corrections.Comment: 5 pages, 12 figures, references added, version to appear in EP

    Effective theoretical approach of Gauge-Higgs unification model and its phenomenological applications

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    We derive the low energy effective theory of Gauge-Higgs unification (GHU) models in the usual four dimensional framework. We find that the theories are described by only the zero-modes with a particular renormalization condition in which essential informations about GHU models are included. We call this condition ``Gauge-Higgs condition'' in this letter. In other wards, we can describe the low energy theory as the SM with this condition if GHU is a model as the UV completion of the Standard Model. This approach will be a powerful tool to construct realistic models for GHU and to investigate their low energy phenomena.Comment: 18 pages, 2 figures; Two paragraphs discussing the applicable scope of this approach are adde

    Anarchy and Hierarchy

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    We advocate a new approach to study models of fermion masses and mixings, namely anarchy proposed in hep-ph/9911341. In this approach, we scan the O(1) coefficients randomly. We argue that this is the correct approach when the fundamental theory is sufficiently complicated. Assuming there is no physical distinction among three generations of neutrinos, the probability distributions in MNS mixing angles can be predicted independent of the choice of the measure. This is because the mixing angles are distributed according to the Haar measure of the Lie groups whose elements diagonalize the mass matrices. The near-maximal mixings, as observed in the atmospheric neutrino data and as required in the LMA solution to the solar neutrino problem, are highly probable. A small hierarchy between the Delta m^2 for the atmospheric and the solar neutrinos is obtained very easily; the complex seesaw case gives a hierarchy of a factor of 20 as the most probable one, even though this conclusion is more measure-dependent. U_{e3} has to be just below the current limit from the CHOOZ experiment. The CP-violating parameter sin delta is preferred to be maximal. We present a simple SU(5)-like extension of anarchy to the charged-lepton and quark sectors which works well phenomenologically.Comment: 26 page

    Field-induced metal-insulator transition and switching phenomenon in correlated insulators

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    We study the nonequilibrium switching phenomenon associated with the metal-insulator transition under electric field E in correlated insulator by a gauge-covariant Keldysh formalism. Due to the feedback effect of the resistive current I, this occurs as a first-order transition with a hysteresis of I-V characteristics having a lower threshold electric field (\sim 10^4 Vcm^{-1}) much weaker than that for the Zener breakdown. It is also found that the localized mid-gap states introduced by impurities and defects act as hot spots across which the resonant tunneling occurs selectively, which leads to the conductive filamentary paths and reduces the energy cost of the switching function.Comment: 5 pages, 3 figures. A study on the metal-insulator transition in correlated insulators was adde

    Lack of the Sodium-Driven Chloride Bicarbonate Exchanger NCBE Impairs Visual Function in the Mouse Retina

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    Regulation of ion and pH homeostasis is essential for normal neuronal function. The sodium-driven chloride bicarbonate exchanger NCBE (Slc4a10), a member of the SLC4 family of bicarbonate transporters, uses the transmembrane gradient of sodium to drive cellular net uptake of bicarbonate and to extrude chloride, thereby modulating both intracellular pH (pHi) and chloride concentration ([Cl-]i) in neurons. Here we show that NCBE is strongly expressed in the retina. As GABAA receptors conduct both chloride and bicarbonate, we hypothesized that NCBE may be relevant for GABAergic transmission in the retina. Importantly, we found a differential expression of NCBE in bipolar cells: whereas NCBE was expressed on ON and OFF bipolar cell axon terminals, it only localized to dendrites of OFF bipolar cells. On these compartments, NCBE colocalized with the main neuronal chloride extruder KCC2, which renders GABA hyperpolarizing. NCBE was also expressed in starburst amacrine cells, but was absent from neurons known to depolarize in response to GABA, like horizontal cells. Mice lacking NCBE showed decreased visual acuity and contrast sensitivity in behavioral experiments and smaller b-wave amplitudes and longer latencies in electroretinograms. Ganglion cells from NCBE-deficient mice also showed altered temporal response properties. In summary, our data suggest that NCBE may serve to maintain intracellular chloride and bicarbonate concentration in retinal neurons. Consequently, lack of NCBE in the retina may result in changes in pHi regulation and chloride-dependent inhibition, leading to altered signal transmission and impaired visual function

    Damage mechanisms of pathogenic bacteria in drinking water during chlorine and solar disinfection

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    This study aimed at elucidating the inactivation mechanisms of pathogenic bacteria in drinking water during chlorine and solar disinfection using a simple plating method. The well-known bacterial model Escherichia coli was used as pathogenic bacteria for the experiments. The damage mechanisms of E. coli were evaluated by simple plating method on selective, less selective and non-selective media. Results showed that, injured E. coli were detected at different levels during chlorine and solar disinfection. The use of selective media during water quality control showed effectively the destruction of E. coli during solar disinfection while the removal of E. coli during chlorine disinfection was not ensured. The damage of cell components and/or metabolic functions showed that there is a primary and mainly damage of E. coli during chorine and solar disinfection. Chlorination firstly and mainly damaged membrane cell followed by that of enzymatic functions and nucleic acid; while solar disinfection damaged mainly nucleic acid. The use of simple plating method in water quality control is limited by the choice of plating media depending on the disinfectant used. The understanding of the damage mechanisms of pathogenic bacteria cells during disinfection helps improve drinking water quality control and develops more effective disinfection strategies.© 2016 International Formulae Group. All rights reserved.Keywords: Drinking water, pathogenic bacteria, E. coli, damage mechanisms, chlorine disinfection, solar disinfectio

    New contribution to dimension five operators on proton decay in anomaly mediation scenario

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    In supergravity, effective superpotential relevant to dimension five operators on proton decay processes also leads to supersymmetry breaking terms among sfermions, dimension four operators. These dimension four operators induce the dimension five operators through 1-loop diagrams dressed by gauginos. We find that, in a class of models with the anomaly mediation, the 1-loop contributions can be comparable to those at the tree level. Therefore, such operators have a great impact on proton decay rate. Depending on a universal phase of gaugino masses and soft mass spectrum, the proton decay rate can be enhanced or suppressed.Comment: 8 pages, no figure. A few minor changes have been mad
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