2,495 research outputs found
Nancy (A.B.) Brown to Susan Kean, June 14, 1794
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
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
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
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
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 ; 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 , 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
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
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
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
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
condensate state may occur at densities 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
- …