2,485 research outputs found

    Nancy (A.B.) Brown to Susan Kean, June 14, 1794

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    Nancy Brown wrote to Susan Kean in Philadelphia, Pennsylvania. Nancy informed Susan that she found her husband William confined to their bed upon her return home. He had fallen from a beam from a newly raised house and received a terrible cut that would turn into a scar. Lady Kitty asked to be remembered kindly by Susan and John Kean. Nancy recommended Violet to Lady Kitty but she said she did not have time to attend to the servants and was afraid Violet would not be steady enough for her. The letter was presented to Susan by Coll. Beckwith. Nancy also sent John Kean gloves.https://digitalcommons.kean.edu/lhc_1790s/1633/thumbnail.jp

    Monte-Carlo generator for e+e- annihilation into lepton and hadron pairs with precise radiative corrections

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    Recently, various cross sections of e+e- annihilation into hadrons were accurately measured in the energy range from 0.37 to 1.39 GeV with the CMD-2 detector at the VEPP-2M collider. In the pi+pi- channel a systematic uncertainty of 0.6% has been achieved. A Monte-Carlo Generator Photon Jets (MCGPJ) was developed to simulate events of the Bhabha scattering as well as production of two charged pions, kaons and muons. Based on the formalism of Structure Functions, the leading logarithmic contributions related to the emission of photon jets in the collinear region are incorporated into the MC generator. Radiative corrections (RC) in the first order of alpha are accounted for exactly. The theoretical precision of the cross sections with RC is estimated to be better than 0.2%. Numerous tests of the program as well as comparison with other MC generators and CMD-2 experimental data are presented.Comment: LaTeX, 23 pages with 18 figure

    Inhuman shields - children caught in the crossfire of domestic violence

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    Background. Child abuse is a worldwide scourge. One of its most devastating manifestations is non-accidental head injury (NAHI).Methods. This is a retrospective chart review of children presenting to the Red Cross Children's Hospital trauma unit with a diagnosis of NAHI over a 3-year period.Results. Sixty-eight children were included in the study and 2 different groups were identified. Fifty-three per cent of the children were deliberately injured (median age 2 years), while 47% were allegedly not the intended target of the assailant (median age 9 months). The assailant was male in 65% of the intentional assaults and male in 100% of the unintentional assaults, with the intended adult victim female in 85% of the latter cases. Overall, 85% of the assaults were committed in the child's own home.Conclusions. The high proportion of cases in which a young child was injured unintentionally suggests that these infants effectively become shields in assaults committed by adults. In this context any attempts to deal with child abuse must also address the concurrent intimate partner violence

    A Smirnov-Bickel-Rosenblatt theorem for compactly-supported wavelets

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    In nonparametric statistical problems, we wish to find an estimator of an unknown function f. We can split its error into bias and variance terms; Smirnov, Bickel and Rosenblatt have shown that, for a histogram or kernel estimate, the supremum norm of the variance term is asymptotically distributed as a Gumbel random variable. In the following, we prove a version of this result for estimators using compactly-supported wavelets, a popular tool in nonparametric statistics. Our result relies on an assumption on the nature of the wavelet, which must be verified by provably-good numerical approximations. We verify our assumption for Daubechies wavelets and symlets, with N = 6, ..., 20 vanishing moments; larger values of N, and other wavelet bases, are easily checked, and we conjecture that our assumption holds also in those cases

    Quantum cosmological perfect fluid model and its classical analogue

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    The quantization of gravity coupled to a perfect fluid model leads to a Schr\"odinger-like equation, where the matter variable plays the role of time. The wave function can be determined, in the flat case, for an arbitrary barotropic equation of state p=αρp = \alpha\rho; solutions can also be found for the radiative non-flat case. The wave packets are constructed, from which the expectation value for the scale factor is determined. The quantum scenarios reveal a bouncing Universe, free from singularity. We show that such quantum cosmological perfect fluid models admit a universal classical analogue, represented by the addition, to the ordinary classical model, of a repulsive stiff matter fluid. The meaning of the existence of this universal classical analogue is discussed. The quantum cosmological perfect fluid model is, for a flat spatial section, formally equivalent to a free particle in ordinary quantum mechanics, for any value of α\alpha, while the radiative non-flat case is equivalent to the harmonic oscillator. The repulsive fluid needed to reproduce the quantum results is the same in both cases.Comment: Latex file, 13 page

    Mass singularity and confining property in QED3QED_3

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    We discuss the properties of the position space fermion propagator in three dimensional QED which has been found previouly based on Ward-Takahashi-identity for soft-photon emission vertex and spectral representation.There is a new type of mass singularity which governs the long distance behaviour.It leads the propagator vanish at large distance.This term corresponds to dynamical mass in position space.Our model shows confining property and dynamical mass generation for arbitrary coupling constant.Since we used dispersion retation in deriving spectral function there is a physical mass which sets a mass scale.For finite cut off we obtain the full propagator in the dispersion integral as a superposition of different massses.Low energy behaviour of the proagator is modified to decrease by position dependent mass.In the limit of zero infrared cut-off the propagator vanishes with a new kind of infrared behaviour.Comment: 22pages,4figures,revtex4,Notational sloppiness are crrected.Submitted to JHE

    Scaling Of Chiral Lagrangians And Landau Fermi Liquid Theory For Dense Hadronic Matter

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    We discuss the Fermi-liquid properties of hadronic matter derived from a chiral Lagrangian field theory in which Brown-Rho (BR) scaling is incorporated. We identify the BR scaling as a contribution to Landau's Fermi liquid fixed-point quasiparticle parameter from "heavy" isoscalar meson degrees of freedom that are integrated out from a low-energy effective Lagrangian. We show that for the vector (convection) current, the result obtained in the chiral Lagrangian approach agrees precisely with that obtained in the semi-phenomenological Landau-Migdal approach. This precise agreement allows one to determine the Landau parameter that enters in the effective nucleon mass in terms of the constant that characterizes BR scaling. When applied to the weak axial current, however, these two approaches differ in a subtle way. While the difference is small numerically, the chiral Lagrangian approach implements current algebra and low-energy theorems associated with the axial response that the Landau method misses and hence is expected to be more predictive.Comment: 39 pages, latex with 4 eps figure, modified addresses and reference

    On the Dynamics of Bianchi IX cosmological models

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    A cosmological description of the universe is proposed in the context of Hamiltonian formulation of a Bianchi IX cosmology minimally coupled to a massless scalar field. The classical and quantum results are studied with special attention to the case of closed Friedmann-Robertson-Walker model.Comment: 11 pages, 1 figur

    Negative Kaons in Dense Baryonic Matter

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    Kaon polarization operator in dense baryonic matter of arbitrary isotopic composition is calculated including s- and p-wave kaon-baryon interactions. The regular part of the polarization operator is extracted from the realistic kaon-nucleon interaction based on the chiral and 1/N_c expansion. Contributions of the Lambda(1116), Sigma(1195), Sigma*(1385) resonances are taken explicitly into account in the pole and regular terms with inclusion of mean-field potentials. The baryon-baryon correlations are incorporated and fluctuation contributions are estimated. Results are applied for K- in neutron star matter. Within our model a second-order phase transition to the s-wave K- condensate state occurs at rho_c \gsim 4 \rho_0 once the baryon-baryon correlations are included. We show that the second-order phase transition to the p-wave KK^- condensate state may occur at densities ρc3÷5ρ0\rho_c \sim 3\div 5 \rho_0 in dependence on the parameter choice. We demonstrate that a first-order phase transition to a proton-enriched (approximately isospin-symmetric) nucleon matter with a p-wave K- condensate can occur at smaller densities, \rho\lsim 2 \rho_0. The transition is accompanied by the suppression of hyperon concentrations.Comment: 41 pages, 24 figures, revtex4 styl
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