32 research outputs found
Maternal health, pregnancy and birth outcomes for women involved in care proceedings in Wales: a linked data study
Background: Under the Children Act 1989, local authorities in Wales, UK, can issue care proceedings if they are concerned about the welfare of a child, which can lead to removal of a child from parents. For mothers at risk of child removal, timely intervention during pregnancy may avert the need for this and improve maternal/fetal health; however, little is known about this specific population during the antenatal period. The study examined maternity characteristics of mothers whose infants were subject to care proceedings, with the aim of informing preventative interventions targeted at high risk mothers. Methods: Anonymised administrative data from Cafcass Cymru, who provide child-focused advice and support for family court proceedings in Wales, were linked to population-based maternity and health records held within the Secure Anonymised Information Linkage Databank. Linked data were available for 1111 birth mothers of infants involved in care proceedings between 2015 and 2018. Findings were benchmarked with reference to an age-deprivation-matched comparison group (n = 23,414), not subject to care proceedings but accessing maternity services during this period. Demographic characteristics, maternal health, reproductive history, interaction with midwifery services, and pregnancy and birth outcomes were examined. Descriptive and statistical tests of independence were used. Results: Half of the women in the cohort (49.4%) resided in the most deprived areas. They were more likely to be younger at entry to motherhood (63.5% <21 years-of-age compared to 42.7% in the comparison group), to have mental health (28.6% compared to 8.2%) and substance use issues (10.4% compared to 0.6%) and to smoke (62.7% compared to 24.8%) during pregnancy. The majority first engaged with maternity services within their first trimester of pregnancy (63.5% compared to 84.4%). Babies were more likely to be born preterm (14.2% compared to 6.7%) and, for full-term babies, to have low birthweights (8.0% compared to 2.8%). Conclusion: This novel linkage study highlights multiple vulnerabilities experienced by pregnant mothers who have experienced care proceedings concerning an infant. Policy and practice colleagues require a clearer picture of women’s needs if child protection and health services are to offer effective services which prevent the need for family court proceedings and infant removal
Current correlators to all orders in the quark masses
The contributions to the coefficient functions of the quark and the mixed
quark-gluon condensate to mesonic correlators are calculated for the first time
to all orders in the quark masses, and to lowest order in the strong coupling
constant. Existing results on the coefficient functions of the unit operator
and the gluon condensate are reviewed. The proper factorization of short- and
long-distance contributions in the operator product expansion is discussed in
detail. It is found that to accomplish this task rigorously the operator
product expansion has to be performed in terms of non-normal-ordered
condensates. The resulting coefficient functions are improved with the help of
the renormalization group. The scale invariant combination of dimension 5
operators, including mixing with the mass operator, which is needed for the
renormalization group improvement, is calculated in the leading order.Comment: 24 pages, LateX file, TUM-T31-21/92, 1 postscript file include
Two-Loop Diagrammatics in a Self-Dual Background
Diagrammatic rules are developed for simplifying two-loop QED diagrams with
propagators in a constant self-dual background field. This diagrammatic
analysis, using dimensional regularization, is used to explain how the fully
renormalized two-loop Euler-Heisenberg effective Lagrangian for QED in a
self-dual background field is naturally expressed in terms of one-loop
diagrams. The connection between the two-loop and one-loop vacuum diagrams in a
background field parallels a corresponding connection for free vacuum diagrams,
without a background field, which can be derived by simple algebraic
manipulations. It also mirrors similar behavior recently found for two-loop
amplitudes in N=4 SUSY Yang-Mills theory.Comment: 16 pp, Latex, Axodra
An Analysis of Diagonal and Non-diagonal QCD Sum Rules for Heavy Baryons at Next-to-Leading Order in \alpha_S
We consider diagonal and non-diagonal QCD sum rules for the ground state
heavy baryons to leading order in and at next-to-leading order in
. In the non-diagonal case we evaluate the eight different two-loop
diagrams which determine the perturbative -corrections to the Wilson
coefficient of the quark condensate in the Operator Product Expansion. The QCD
corrections to the non-diagonal sum rules are moderate compared to the QCD
corrections in the diagonal case. We also consider constituent type sum rules
using constituent type interpolating currents. The obtained results are in
reasonable agreement with the corresponding results obtained in the diagonal
case. As central values for the bound state energies we find and . The central values for the residues
are given by and .Comment: 17 pages, LaTeX, 8 figures are included in PostScript forma
Cosmology at the Millennium
One hundred years ago we did not know how stars generate energy, the age of
the Universe was thought to be only millions of years, and our Milky Way galaxy
was the only galaxy known. Today, we know that we live in an evolving and
expanding Universe comprising billions of galaxies, all held together by dark
matter. With the hot big-bang model, we can trace the evolution of the Universe
from the hot soup of quarks and leptons that existed a fraction of a second
after the beginning to the formation of galaxies a few billion years later, and
finally to the Universe we see today 13 billion years after the big bang, with
its clusters of galaxies, superclusters, voids, and great walls. The attractive
force of gravity acting on tiny primeval inhomogeneities in the distribution of
matter gave rise to all the structure seen today. A paradigm based upon deep
connections between cosmology and elementary particle physics -- inflation +
cold dark matter -- holds the promise of extending our understanding to an even
more fundamental level and much earlier times, as well as shedding light on the
unification of the forces and particles of nature. As we enter the 21st
century, a flood of observations is testing this paradigm.Comment: 44 pages LaTeX with 14 eps figures. To be published in the Centennial
Volume of Reviews of Modern Physic
Multiple (inverse) binomial sums of arbitrary weight and depth and the all-order epsilon-expansion of generalized hypergeometric functions with one half-integer value of parameter
We continue the study of the construction of analytical coefficients of the
epsilon-expansion of hypergeometric functions and their connection with Feynman
diagrams. In this paper, we show the following results:
Theorem A: The multiple (inverse) binomial sums of arbitrary weight and depth
(see Eq. (1.1)) are expressible in terms of Remiddi-Vermaseren functions.
Theorem B: The epsilon expansion of a hypergeometric function with one
half-integer value of parameter (see Eq. (1.2)) is expressible in terms of the
harmonic polylogarithms of Remiddi and Vermaseren with coefficients that are
ratios of polynomials. Some extra materials are available via the www at this
http://theor.jinr.ru/~kalmykov/hypergeom/hyper.htmlComment: 24 pages, latex with amsmath and JHEP3.cls; v2: some typos corrected
and a few references added; v3: few references added
In-medium operator product expansion for heavy-light-quark pseudoscalar mesons
The operator product expansion (OPE) for heavy-light-quark pseudoscalar
mesons (D-mesons and B-mesons) in medium is determined, both for a moving meson
with respect to the surrounding medium as well as for a meson at rest. First of
all, the OPE is given in terms of normal-ordered operators up to mass dimension
5, and the mass of the heavy-quark and the mass of the light-quark are kept
finite. The Wilson coefficients of such an expansion are infrared (IR)
divergent in the limit of a vanishing light-quark mass. A consistent separation
of scales necessitates an OPE in terms of non-normal-ordered operators, which
implies operator mixing, where the IR-divergences are absorbed into the
operators. It is shown that the Wilson coefficients of such an expansion are
IR-stable, and the limit of a vanishing light-quark mass is perfomed. Details
of the major steps for the calculation of the Wilson coefficients are
presented. By a comparison with previous results obtained by other theoretical
groups we have found serious disagreements.Comment: 51 pages, 3 figure
QCD moment sum rules for Coulomb systems: the charm and bottom quark masses
In this work the charm and bottom quark masses are determined from QCD moment
sum rules for the charmonium and upsilon systems. To illustrate the special
character of these sum rules when applied to Coulomb systems we first set up
and study the behaviour of the sum rules in quantum mechanics. In our analysis
we include both the results from nonrelativistic QCD and perturbation theory at
next-next-to-leading order. The moments are evaluated at different values of
q^2 which correspond to different relative influence among the theoretical
contributions. In the numerical analysis we obtain the masses by choosing
central values for all input parameters. The error is estimated from a
variation of these parameters. First, the analysis is performed in the pole
mass scheme. Second, we employ the potential-subtracted mass in intermediate
steps of the calculation to then infer the quark masses in the MS-scheme. Our
final results for the pole- and MS-masses are: M_c = 1.75 \pm 0.15 GeV,
m_c(m_c) = 1.19 \pm 0.11 GeV, M_b = 4.98 \pm 0.125 GeV and m_b(m_b) = 4.24 \pm
0.10 GeV.Comment: 55 pages, 12 figures. References added, discussions extended. To
appear in Phys. Rev.
Leptonic and Semileptonic Decays of Charm and Bottom Hadrons
We review the experimental measurements and theoretical descriptions of
leptonic and semileptonic decays of particles containing a single heavy quark,
either charm or bottom. Measurements of bottom semileptonic decays are used to
determine the magnitudes of two fundamental parameters of the standard model,
the Cabibbo-Kobayashi-Maskawa matrix elements and . These
parameters are connected with the physics of quark flavor and mass, and they
have important implications for the breakdown of CP symmetry. To extract
precise values of and from measurements, however,
requires a good understanding of the decay dynamics. Measurements of both charm
and bottom decay distributions provide information on the interactions
governing these processes. The underlying weak transition in each case is
relatively simple, but the strong interactions that bind the quarks into
hadrons introduce complications. We also discuss new theoretical approaches,
especially heavy-quark effective theory and lattice QCD, which are providing
insights and predictions now being tested by experiment. An international
effort at many laboratories will rapidly advance knowledge of this physics
during the next decade.Comment: This review article will be published in Reviews of Modern Physics in
the fall, 1995. This file contains only the abstract and the table of
contents. The full 168-page document including 47 figures is available at
http://charm.physics.ucsb.edu/papers/slrevtex.p
spectroscopy
In the framework of potential models for heavy quarkonium the mass spectrum
for the system () is considered. Spin-dependent splittings, taking
into account a change of a constant for effective Coulomb interaction between
the quarks, and widths of radiative transitions between the () levels
are calculated. In the framework of QCD sum rules, masses of the lightest
vector and pseudoscalar states are estimated, scaling relation
for leptonic constants of heavy quarkonia is derived, and the leptonic constant
is evaluated.Comment: IHEP 94-51, LATEX, 39 page