25,305 research outputs found

### The Legacy of ERA, Privatization and the Policy Ratchet

This article explores the ways in which the neo-liberal impetus toward the privatization of state schooling signalled in the Education Reform Act 1988 (ERA) has become embedded in the English school system. Four main points are made. First, that ERA itself was of huge strategic rather than substantive importance as far as privatization is concerned. Second, by tracing the lineage of privatization from ERA onwards a 'ratchet' effect of small and incremental policy moves can be identified, which have disseminated, embedded and naturalized privatization within public sector provision. Third, that while privatization has been taken up and taken much further by New Labour than it had been by the Conservatives there are differences between the two sets of governments in the role of privatization in education policy and the role of the state. Fourth, the participation of private providers in the planning and delivery of state services has put the private sector at the very heart of policy. At points the article draws upon interviews conducted with private sector providers. © 2008 Sage Publications

### Analysis of the $B \to K^*_2(1430), a_2(1320), f_2(1270)$ form-factors with light-cone QCD sum rules

In this article, we study the $B \to K^*_2(1430)$, $a_2(1320)$, $f_2(1270)$
form-factors with the light-cone QCD sum rules, where the $B$-meson light-cone
distribution amplitudes are used. In calculations, we observe that the
line-shapes of the $B$-meson light-cone distribution amplitude $\phi_+(\omega)$
have significant impacts on the values of the form-factors, and expect to
obtain severe constraints on the parameters of the $B$-meson light-cone
distribution amplitudes from the experimental data in the future.Comment: 19 pages, 6 figures, slight revisio

### Photocurrent in conjugated polymers

Nonlinear photocurrent carriers in conjugated polymers, such as polarons,
bipolarons and solitons, are considered at low photon energies where a
tunnelling process is necessary. We show that polarons usually dominate the
photocurrent I due to a novel electric field assisted tunnelling for which
ln(I) ~ -E^{-2/3}. For near degenerate polymers an electric field E which
exceeds the confinement potential and frequencies above twice the soliton
energy, soliton tunnelling is favored. Photocurrent data can then be used to
identify the remarkable phenomenon of soliton conduction.Comment: 4 pages, 2 eps figures, Revte

### Renormalizability of Effective Scalar Field Theory

We present a comprehensive discussion of the consistency of the effective
quantum field theory of a single $Z_2$ symmetric scalar field. The theory is
constructed from a bare Euclidean action which at a scale much greater than the
particle's mass is constrained only by the most basic requirements; stability,
finiteness, analyticity, naturalness, and global symmetry. We prove to all
orders in perturbation theory the boundedness, convergence, and universality of
the theory at low energy scales, and thus that the theory is perturbatively
renormalizable in the sense that to a certain precision over a range of such
scales it depends only on a finite number of parameters. We then demonstrate
that the effective theory has a well defined unitary and causal analytic
S--matrix at all energy scales. We also show that redundant terms in the
Lagrangian may be systematically eliminated by field redefinitions without
changing the S--matrix, and discuss the extent to which effective field theory
and analytic S--matrix theory are actually equivalent. All this is achieved by
a systematic exploitation of Wilson's exact renormalization group flow
equation, as used by Polchinski in his original proof of the renormalizability
of conventional $\varphi^4$-theory.Comment: 80 pages, TeX, OUTP-93-23P, CERN-TH.7067/93. Many minor revisions,
and several new paragraph

### Operator Relations for SU(3) Breaking Contributions to K and K* Distribution Amplitudes

We derive constraints on the asymmetry a1 of the momentum fractions carried
by quark and antiquark in K and K* mesons in leading twist. These constraints
follow from exact operator identities and relate a1 to SU(3) breaking
quark-antiquark-gluon matrix elements which we determine from QCD sum rules.
Comparing our results to determinations of a1 from QCD sum rules based on
correlation functions of quark currents, we find that, for a1^\parallel(K*) the
central values agree well and come with moderate errors, whereas for a1(K) and
a1^\perp(K*) the results from operator relations are consistent with those from
quark current sum rules, but come with larger uncertainties. The consistency of
results confirms that the QCD sum rule method is indeed suitable for the
calculation of a1. We conclude that the presently most accurate predictions for
a1 come from the direct determination from QCD sum rules based on correlation
functions of quark currents and are given by: a1(K) = 0.06\pm 0.03,
a1^\parallel(K*) = 0.03\pm 0.02, a1^\perp(K*) = 0.04\pm 0.03.Comment: 21 page

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