169 research outputs found

    On Stability of the Three 3-brane Model

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    We show that the Goldberger-Wise mechanism for the three 3-brane scenario proposed by Kogan et al. stabilizes the radion. We find that the system of 3-branes stabilizes in such a way that the loss in the scale factor is insignificant. That is, the negative tension brane chooses to stay close to the visible brane

    Radion effects on unitarity in gauge-boson scattering

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    The scalar field associated with fluctuations in the positions of the two branes, the ``radion'', plays an important role determining the cosmology and collider phenomenology of the Randall-Sundrum solution to the hierarchy problem. It is now well known that the radion mass is of order the weak scale, and that its couplings to standard model fields are order 1/TeV to the trace of the energy momentum tensor. We calculate longitudinal vector boson scattering amplitudes to explore the constraints on the radion mass and its coupling from perturbative unitarity. The scattering cross section can indeed become non-perturbative at energies prior to reaching the TeV brane cutoff scale, but only when some curvature-Higgs mixing on the TeV brane is present. We show that the coefficient of the curvature-Higgs mixing operator must be less than about 3 for the 4-d effective theory to respect perturbative unitarity up to the TeV brane cutoff scale. Mass bounds on the Higgs boson and the radion are also discussed.Comment: 17 pages, LaTeX, 5 eps figures, uses epsf.sty and axodraw.st

    Radion effects on the production of an intermediate-mass scalar and Z at LEP II

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    We have studied the e+eZϕiZjje^+ e^- \to Z \phi_i \to Z jj process, where ϕi\phi_i is the Higgs and/or radion bosons. The implications of the radion effects on the preliminary ALEPH data are also discussed. The case of the lighter radion than Higgs boson is disfavored by the ALEPH analyses of the bb tagged four-jet data, since the radion predominantly decays into two gluon jets due to the QCD trace anomaly. If the radion is highly degenerate in mass with the Higgs, the cross section can be increased more than at one sigma level, with natural scale of the vacuum expectation value of the radion.Comment: 10 pages, 1 Postscript figure, final version to appear in PR

    Effect of Alcohol and Nicotine on Fertility of Male Albino Mice

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    Abuse of recreational drugs such as alcohol and nicotine may be genotoxic and may have detrimental effect on the male fertility which was aimed to be investigated through this present study using mice model systems. A total of 60 mice were divided into three groups, viz.; control group (n=20), and two groups of alcohol treated (n=20) and nicotine treated mice groups (n=20), administered in recommended dose amount for 90 days. Representative numbers of mice were sacrificed on 10th, 30th and 90th day from each group and the testes were collected. DNA and RNA was extracted from the collected tissue following standard protocol; followed by RAPD-PCR and Real time PCR based analysis of extracted DNA and cDNA, prepared from isolated RNA, for Rbmy1 gene expression analysis, respectively. ?-actin was used as internal normalization control for Real time PCR analysis. Remarkable changes were observed in the RAPD profiles, based on difference in band pattern profile as observed in alcohol treated and nicotine induced cases compared to controls; thereby clearly indicating the effect of recreational drug on the genome of the host in comparison to untreated controls. The differential expression profile of Rbmy1 mRNA in the nicotine model, showed significant down regulation compared to control (p=0.045), and non-significant when compared to alcoholic model cohorts (p=0.307).The observation also showed differences of Rbmy1 mRNA expression in alcoholic cases compared to controls (p=0.782). The present study indicates that consumption of recreation drugs such as nicotine may play an important role in disturbing the genome integrity and expression of key gene associated with male fertility, thereby disposing to male infertility

    Unitarity constraints on the stabilized Randall-Sundrum scenario

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    Recently proposed stabilization mechanism of the Randall-Sundrum metric gives rise to a scalar radion, which couples universally to matter with a weak interaction (1\simeq 1 TeV) scale. Demanding that gauge boson scattering as described by the effective low enerrgy theory be unitary upto a given scale leads to significant constraints on the mass of such a radion.Comment: 10 page Latex 2e file including 4 postscript figures. Accepted in Journal of Physics

    Muon anomalous magnetic moment in string inspired extended family models

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    We propose a standard model minimal extension with two lepton weak SU(2) doublets and a scalar singlet to explain the deviation of the measured anomalous magnetic moment of the muon from the standard model expectation. This scheme can be naturally motivated in string inspired models such as E_6 and AdS/CFT.Comment: 9 pages, RevTeX, 2 figures, version to be published in Phys. Rev.
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