6,024 research outputs found

    Reply to ``Comment on `Majoron emitting neutrinoless double beta decay in the electroweak chiral gauge extensions' ''

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    We demonstrate that in the process of deducing the constraint on the electroweak mixing angle θW\theta_{W} in our paper, we have indeed been working with three mass scales while implementing (331) model.Comment: Revtex, 3pages, Reply to hep-ph/9902448, Submitted to Phys. Rev.

    The Evolution of Luminous Compact Blue Galaxies: Disks or Spheroids?

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    Luminous compact blue galaxies (LCBGs) are a diverse class of galaxies characterized by high luminosities, blue colors, and high surface brightnesses. Residing at the high luminosity, high mass end of the blue sequence, LCBGs sit at the critical juncture of galaxies that are evolving from the blue to the red sequence. Yet we do not understand what drives the evolution of LCBGs, nor how they will evolve. Based on single-dish HI observations, we know that they have a diverse range of properties. LCBGs are HI-rich with M(HI)=10^{9-10.5} M(sun), have moderate M(dyn)=10^{10-12} M(sun), and 80% have gas depletion timescales less than 3 Gyr. These properties are consistent with LCBGs evolving into low-mass spirals or high mass dwarf ellipticals or dwarf irregulars. However, LCBGs do not follow the Tully-Fisher relation, nor can most evolve onto it, implying that many LCBGs are not smoothly rotating, virialized systems. GMRT and VLA HI maps confirm this conclusion revealing signatures of recent interactions and dynamically hot components in some local LCBGs, consistent with the formation of a thick disk or spheroid. Such signatures and the high incidence of close companions around LCBGs suggest that star formation in local LCBGs is likely triggered by interactions. The dynamical masses and apparent spheroid formation in LCBGs combined with previous results from optical spectroscopy are consistent with virial heating being the primary mechanism for quenching star formation in these galaxies.Comment: 4 pages, 1 figure, to appear in "Hunting for the Dark: The Hidden Side of Galaxy Formation", Malta, 19-23 Oct. 2009, eds. V.P. Debattista & C.C. Popescu, AIP Conf. Se

    Remark on the vectorlike nature of the electromagnetism and the electric charge quantization

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    In this work we study the structure of the electromagnetic interactions and the electric charge quantization in gauge theories of electroweak interactions based on semi-simple groups. We show that in the standard model of the electroweak interactions the structure of the electromagnetic interactions is strongly correlated to the quantization pattern of the electric charges. We examine these two questions also in all possible chiral bilepton gauge models of the electroweak interactions. In all they we can explain the vectorlike nature of the electromagnetic interactions and the electric charge quantization together demanding nonvanishing fermion masses and the anomaly cancellations.Comment: 17 pages, latex, no figure

    Glomerulocystic kidney in two red piranhas Pygocentrus nattereri.

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    Glomerulocystic kidney (GCK) is defined by a dilatation of the Bowman's space (greater than 2 times the normal size) of more than 5% of all glomeruli. Although GCK has been occasionally documented in dogs, cats, and humans with renal failure, in fish, reports of spontaneous GCK are rare. For the present study, 2 captive adult red piranhas Pygocentrus nattereri from a closed population were submitted for post-mortem examination. Clinical history included lethargy, inappetence, dyspnea, and altered buoyancy. Macroscopically, the fish displayed coelomic distension and ascites. The kidneys were markedly enlarged and dark yellow. Histologically, Bowman's space was noticeably dilated, occasionally with atrophic glomerular tufts. Degeneration and necrosis of the tubular epithelium, infiltration, and nephrocalcinosis were also present. To the authors' knowledge, this present study is the first report of spontaneously occurring GCK in red piranhas and freshwater fish in general. Despite being rare, GCK is a condition with the potential to impair the health of fish and mammals, and further studies are needed to shed new light on this condition

    The strong-CP question in SU(3)_c X SU(3)_L X U(1)_N models

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    We analyze two recent models based on the gauge group SU(3)c×_c\timesSU(3)L×_L\timesU(1)N_N where each generation is not anomaly-free, but anomaly cancels when three generations are taken into account. We show that the most general Yukawa couplings of these models admit of a Peccei-Quinn symmetry. This symmetry can be extended to the entire Lagrangian by using extra fields in a very elegant way so that the resulting axion can be made invisible.Comment: Latex, 8 pages, no figure

    Investigation of Hamamatsu H8500 phototubes as single photon detectors

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    We have investigated the response of a significant sample of Hamamatsu H8500 MultiAnode PhotoMultiplier Tubes (MAPMTs) as single photon detectors, in view of their use in a ring imaging Cherenkov counter for the CLAS12 spectrometer at the Thomas Jefferson National Accelerator Facility. For this, a laser working at 407.2nm wavelength was employed. The sample is divided equally into standard window type, with a spectral response in the visible light region, and UV-enhanced window type MAPMTs. The studies confirm the suitability of these MAPMTs for single photon detection in such a Cherenkov imaging application

    Minimal extended flavor groups, matter fields chiral representations, and the flavor question

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    We show the specific unusual features on chiral gauge anomalies cancellation in the minimal, necessarily 3-3-1, and the largest 3-4-1 weak isospin chiral gauge semisimple group leptoquark-bilepton extensions of the 3-2-1 conventional standard model of nuclear and electromagnetic interactions. In such models a natural explanation for the fundamental question of fermion generation replication arises from the self-consistency of a local gauge quantum field theory, which constrains the number of the QFD fermion families to the QCD color charges.Comment: 10 pages. <[email protected]

    Majoron emitting neutrinoless double beta decay in the electroweak chiral gauge extensions

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    Fundamental mechanisms for Majoron emitting neutrinoless double beta decay in SU(3)_C x G_W x U(1) models, for electroweak flavor chiral extensions, G_W = SU(3)_L and SU(4)_L are pointed out. Both kinds of known Majoron emitting processes, charged Majoron emitting where the massless Nambu-Goldstone boson itself carries lepton charge, L=2L=-2, and the ordinary Majoron emitting where the boson has a small mass are found possible. PACS numbers: 11.15.Ex, 12.60.Fr, 14.80.CpComment: 18 pages, Revtex, 3 Postscript figures. To be published in Phys.Rev.D(1 May 1998
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