12,236 research outputs found

    On Some properties of Di-hadronic states

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    The binding energies of di- hadronic states have been calculated assuming a 'molecular' interaction provided by the asymptotic expression of the residual confined gluon exchange potential between the component hadrons in the system. Meson- meson and meson- baryon states have been studied in detail and a mass formula has been used to calculate total mass of the 'molecules'.Comment: 11 page

    Flavor-oscillation clocks, continuous quantum measurements and a violation of Einstein equivalence principle

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    The relation between Einstein equivalence principle and a continuous quantum measurement is analyzed in the context of the recently proposed flavor-oscillation clocks, an idea pioneered by Ahluwalia and Burgard (Gen. Rel Grav. Errata 29, 681 (1997)). We will calculate the measurement outputs if a flavor-oscillation clock, which is immersed in a gravitational field, is subject to a continuous quantum measurement. Afterwards, resorting to the weak equivalence principle, we obtain the corresponding quantities in a freely falling reference frame. Finally, comparing this last result with the measurement outputs that would appear in a Minkowskian spacetime it will be found that they do not coincide, in other words, we have a violation of Einstein equivalence principle. This violation appears in two different forms, namely: (i) the oscillation frequency in a freely falling reference frame does not match with the case predicted by general relativity, a feature previously obtained by Ahluwalia; (ii) the probability distribution of the measurement outputs, obtained by an observer in a freely falling reference frame, does not coincide with the results that would appear in the case of a Minkowskian spacetime.Comment: 16 pages, accepted in Mod. Phys. Letts.

    Dissipative collisions in 16^{16}O + 27^{27}Al at Elab_{lab}=116 MeV

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    The inclusive energy distributions of fragments (3≀\leqZ≀\leq7) emitted in the reaction 16^{16}O + 27^{27}Al at Elab=E_{lab} = 116 MeV have been measured in the angular range Ξlab\theta_{lab} = 15∘^\circ - 115∘^\circ. A non-linear optimisation procedure using multiple Gaussian distribution functions has been proposed to extract the fusion-fission and deep inelastic components of the fragment emission from the experimental data. The angular distributions of the fragments, thus obtained, from the deep inelastic component are found to fall off faster than those from the fusion-fission component, indicating shorter life times of the emitting di-nuclear systems. The life times of the intermediate di-nuclear configurations have been estimated using a diffractive Regge-pole model. The life times thus extracted (∌1−5×10−22\sim 1 - 5\times 10^{-22} Sec.) are found to decrease with the increase in the fragment charge. Optimum Q-values are also found to increase with increasing charge transfer i.e. with the decrease in fragment charge.Comment: 9 pages, 4 figures, 1 tabl

    Constraints on the mass of the superlight gravitino from the muon anomaly

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    We reexamine the limits on the gravitino mass supplied by the muon anomaly in the frame of supergravity models with a superlight gravitino and a superlight scalar S and a superlight pseudoscalar P.Comment: 7 pages, REVTeX with 5 figures. Uses epsfi

    Correlations around an interface

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    We compute one-loop correlation functions for the fluctuations of an interface using a field theory model. We obtain them from Feynman diagrams drawn with a propagator which is the inverse of the Hamiltonian of a Poschl-Teller problem. We derive an expression for the propagator in terms of elementary functions, show that it corresponds to the usual spectral sum, and use it to calculate quantities such as the surface tension and interface profile in two and three spatial dimensions. The three-dimensional quantities are rederived in a simple, unified manner, whereas those in two dimensions extend the existing literature, and are applicable to thin films. In addition, we compute the one-loop self-energy, which may be extracted from experiment, or from Monte Carlo simulations. Our results may be applied in various scenarios, which include fluctuations around topological defects in cosmology, supersymmetric domain walls, Z(N) bubbles in QCD, domain walls in magnetic systems, interfaces separating Bose-Einstein condensates, and interfaces in binary liquid mixtures.Comment: RevTeX, 13 pages, 6 figure

    Measurement induced quantum-classical transition

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    A model of an electrical point contact coupled to a mechanical system (oscillator) is studied to simulate the dephasing effect of measurement on a quantum system. The problem is solved at zero temperature under conditions of strong non-equilibrium in the measurement apparatus. For linear coupling between the oscillator and tunneling electrons, it is found that the oscillator dynamics becomes damped, with the effective temperature determined by the voltage drop across the junction. It is demonstrated that both the quantum heating and the quantum damping of the oscillator manifest themselves in the current-voltage characteristic of the point contact.Comment: in RevTex, 1 figure, corrected notatio

    Domain walls and perturbation theory in high temperature gauge theory: SU(2) in 2+1 dimensions

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    We study the detailed properties of Z_2 domain walls in the deconfined high temperature phase of the d=2+1 SU(2) gauge theory. These walls are studied both by computer simulations of the lattice theory and by one-loop perturbative calculations. The latter are carried out both in the continuum and on the lattice. We find that leading order perturbation theory reproduces the detailed properties of these domain walls remarkably accurately even at temperatures where the effective dimensionless expansion parameter, g^2/T, is close to unity. The quantities studied include the surface tension, the action density profiles, roughening and the electric screening mass. It is only for the last quantity that we find an exception to the precocious success of perturbation theory. All this shows that, despite the presence of infrared divergences at higher orders, high-T perturbation theory can be an accurate calculational tool.Comment: 75 pages, LaTeX, 14 figure

    Dynamically Warped Theory Space and Collective Supersymmetry Breaking

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    We study deconstructed gauge theories in which a warp factor emerges dynamically and naturally. We present nonsupersymmetric models in which the potential for the link fields has translational invariance, broken only by boundary effects that trigger an exponential profile of vacuum expectation values. The spectrum of physical states deviates exponentially from that of the continuum for large masses; we discuss the effects of such exponential towers on gauge coupling unification. We also present a supersymmetric example in which a warp factor is driven by Fayet-Iliopoulos terms. The model is peculiar in that it possesses a global supersymmetry that remains unbroken despite nonvanishing D-terms. Inclusion of gravity and/or additional messenger fields leads to the collective breaking of supersymmetry and to unusual phenomenology.Comment: 28 pages LaTeX, JHEP format, 7 eps figures (v2: reference added

    Molecular Characterization and SNP Detection of CD14 Gene of Crossbred Cattle

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    CD14 is an important molecule for innate immunity that can act against a wide range of pathogens. The present paper has characterized CD14 gene of crossbred (CB) cattle (Bos indicus×Bos taurus). Cloning and sequence analysis of CD14 cDNA revealed 1119 nucleotide long open reading frame encoding 373 amino acids protein and 20 amino acids signal peptide. CB cattle CD14 gene exhibited a high percentage of nucleotide identity (59.3–98.1%) with the corresponding mammalian homologs. Cattle and buffalo appear to have diverged from a common ancestor in phylogenetic analysis. 25 SNPs with 17 amino acid changes were newly reported and the site for mutational hot-spot was detected in CB cattle CD14 gene. Non-synonymous substitutions exceeding synonymous substitutions indicate the evolution of this protein through positive selection among domestic animals. Predicted protein structures obtained from deduced amino acid sequence indicated CB cattle CD14 molecule to be a receptor with horse shoe-shaped structure. The sites for LPS binding, LPS signalling, leucine-rich repeats, putative N-linked glycosylation, O-linked glycosylation, glycosyl phosphatidyl inositol anchor, disulphide bridges, alpha helix, beta strand, leucine rich nuclear export signal, leucine zipper and domain linker were predicted. Most of leucine and cysteine residues remain conserved across the species
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