265 research outputs found

    Statistical Processing of Subjective Test Data for Sound Quality Evaluation of Automotive Horn

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    Product sound quality has a significant role in buying decision and customer satisfaction. An often used method to assess the sound quality of any product or equipment is a subjective listening test where the sound is heard by a panel of subjects (jury) who then rate the sound quality. Subjects use a semantic differential rating wherein they evaluate the presented sounds based on a bipolar variable. The two extremes of the rating scale are labeled with an adjective and its antonym respectively. In the present study, a subjective listening test has been conducted to assess sound quality of automotive horns. The data obtained are then analyzed using statistics to gain insights. Twenty two horn sound samples were judged by thirty participants aged 20-40 years who had normal hearing. Binaural head set (BHS) instrument was used to record horn sound samples in open ground (neglecting wind noise effect). Sounds are recorded two meter from horn in front direction and used for subjective test. For the subjective test and subsequent statistical analysis, a four step procedure has been used. In the first step, the participants were asked to rate the sound quality for each horn based on seven bipolar variables. These bipolar variables are soft/loud, calm/frightening, slow/fast, relax/tense, safe/danger, vague/distinct and pleasant/unpleasant. For each bipolar variable, a seven verbal interval scale was used ranging from one extreme to another in degree, for example extremely pleasant to extremely unpleasant

    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

    Unparticle physics and lepton flavor violating radion decays in the Randall-Sundrum scenario

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    We predict the branching ratios of the lepton flavor violating radion decays r -> e^{\pm} \mu^{\pm}, r -> e^{\pm} \tau^{\pm} and r ->\mu^{\pm} \tau^{\pm} in the framework of the Randall-Sundrum scenario that the lepton flavor violation is carried by the scalar unparticle mediation. We observe that their BRs are strongly sensitive to the unparticle scaling dimension and, for its small values, the branching ratios can reach to the values of the order of 10^{-8}, for the heavy lepton flavor case.Comment: 21 pages, 11 Figures, 1 Tabl

    Z boson pair production at LHC in a stabilized Randall-Sundrum scenario

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    We study the Z boson pair production at LHC in the Randall-Sundrum scenario with the Goldberger-Wise stabilization mechanism. It is shown that comprehensive account of the Kaluza-Klein graviton and radion effects is crucial to probe the model: The KK graviton effects enhance the cross section of ggZZg g \to Z Z on the whole so that the resonance peak of the radion becomes easy to detect, whereas the RS effects on the qqˉZZq\bar{q} \to Z Z process are rather insignificant. The pTp_T and invariant-mass distributions are presented to study the dependence of the RS model parameters. The production of longitudinally polarized Z bosons, to which the SM contributions are suppressed, is mainly due to KK gravitons and the radion, providing one of the most robust methods to signal the RS effects. The 1σ1 \sigma sensitivity bounds on (Λπ,mϕ)(\Lambda_\pi, m_\phi) with k/MPl=0.1k/M_{\rm Pl} =0.1 are also obtained such that the effective weak scale Λπ\Lambda_\pi of order 5 TeV can be experimentally probed.Comment: 28 pages, LaTex file, 18 eps figure

    Critical Behavior of a Four-Fermion Schwinger-Dyson Equation

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    We study the Schwinger-Dyson equation associated with a chirality- changing fermion 4-point function in a strongly-coupled U(1)U(1) gauge theory. After making appropriate simplifications, we solve the equation numerically via a relaxation method. Our analysis provides an estimate of the critical coupling and it gives some indication as to the general momentum dependence of the 4-point function.Comment: version to be published, postscript fil

    Lepton Dipole Moments and Rare Decays in the CP-violating MSSM with Nonuniversal Soft-Supersymmetry Breaking

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    We investigate the muon anomalous magnetic dipole moment (MDM), the muon electric dipole moment (EDM) and the lepton-flavour-violating decays of the τ\tau-lepton, τμγ\tau \to \mu \gamma and τ3μ\tau\to 3\mu, in the CP-violating Minimal Supersymmetric Standard Model (MSSM) with nonuniversal soft-supersymmetry breaking. We evaluate numerically the muon EDM and the branching ratios B(τμγ)B(\tau \to \mu\gamma) and B(τ3μ)B(\tau \to 3\mu), after taking into account the experimental constraints from the electron EDM and muon MDM. Upon imposition of the experimental limits on our theoretical predictions for the aforementioned branching ratios and the muon MDM, we obtain an upper bound of about 1023ecm10^{-23} e\cdot cm on the muon EDM which lies well within the explorable reach of the proposed experiment at BNL.Comment: Latex, 26 pages, 8 figures, accepted for publication in Phys. Rev.

    Gauged Yukawa Matrix Models and 2-Dimensional Lattice Theories

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    We argue that chiral symmetry breaking in three dimensional QCD can be identified with N\'eel order in 2-dimensional quantum antiferromagnets. When operators which drive the chiral transition are added to these theories, we postulate that the resulting quantum critical behavior is in the universality class of gauged Yukawa matrix models. As a consequence, the chiral transition is typically of first order, although for a limited class of parameters it can be second order with computable critical exponents.Comment: LaTeX, 11 page

    Cymbopogon citratus L. essential oil as a potential antifungal agent against key weed moulds of Pleurotus spp. spawn

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    The essential oil of Cymbopogon citratus L. (250–1500 p.p.m.) was tested in vitro for antifungal activity against seven Pleurotus spp. spawn-contaminating fungi, viz. Aspergillus flavus, A. fumigatus, A. niger, Alternaria alternata, Penicillium citrinum, Curvularia lunata and Trichoderma harzianum. Oil-enrichment resulted in significant (p < 0.05) reduction of growth for the pathogens examined. Fungal spore production inhibited up to 80% at 250 p.p.m. of the oil except for C. lunata, which was inhibited by only 30%. In the higher oil concentration (1500 p.p.m.) employed, fungal sporulation was completely retarded. Lemongrass oil reduces spore germination in A. flavus, A. fumigatus, A. alternata, P. citrinum and T. harzianum, with the effects dependent on oil concentration. However, lemongrass oil at 250 p.p.m. accelerated spore germination for A. niger and P. citrinum. Indeed, further increase in oil concentration shows complete inhibition. Among the pathogens, C. lunata was found to be most resistant strain, while A. niger was the most sensitive strain against lemongrass oil. Copyright © 2007 John Wiley & Sons, Ltd

    Electric charge quantization and the muon anomalous magnetic moment

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    We investigate some proposals to solve the electric charge quantization puzzle, which simultaneously explain the recent measured deviation on the muon anomalous magnetic moment. For this we assess extensions of the Electro-Weak Standard Model spanning modifications on the scalar sector only. It is interesting to verify that one can have modest extensions which easily account for the solution for both problems.Comment: 20 pages, 1 figures, needs macro axodraw.st

    Top-Charm Associated Production in High Energy e+ee^+e^- Collisions

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    The possibility of exploring the flavor changing neutral current tcZ/tcγtcZ/tc\gamma couplings in the production vertex for the reaction \epem\to t\bar c + \bar tc is examined. Using a model independent parameterization for the effective Lagrangian to describe the most general three-point interactions, production cross sections are found to be relatively small at LEP II, but potentially sizeable at higher energy \epem colliders. The kinematic characteristics of the signal are studied and a set of cuts are devised for clean separation of the signal from background. The resulting sensitivity to anomalous flavor changing couplings at LEP II with an integrated luminosity of 4×5004\times 500 pb1^{-1} is found to be comparable to their present indirect constraints from loop processes, while at higher energy colliders with 0.510.5-1 TeV center-of-mass energy and 50-200 fb1^{-1} luminosity, one expects to reach a sensitivity at or below the percentage level.Comment: Latex, 22 page
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