Threshold Corrections in Precision LHC Physics: QED otimes QCD

With an eye toward LHC processes in which theoretical precisions of 1 percent are desired, we introduce the theory of the simultaneous YFS resummation of QED and QCD to compute the size of the expected resummed soft radiative threshold effects in precision studies of heavy particle production at the LHC. Our results show that both QED and QCD soft threshold effects must be controlled to be on the conservative side to achieve such precision goals.Comment: 4 pages, no figures; presented by B.F.L. Ward in DPF200

Electric fields from a horizontal electric dipole situated above a layered lunar half-space Final report

Electric fields from horizontal electric dipole situated above layered lunar half spac

Reexamining evidence-based practice in community corrections: beyond 'a confined view' of what works

This article aims to reexamine the development and scope of evidence-based practice (EBP) in community corrections by exploring three sets of issues. Firstly, we examine the relationships between the contested purposes of community supervision and their relationships to questions of evidence. Secondly, we explore the range of forms of evidence that might inform the pursuit of one purpose of supervision—the rehabilitation of offenders—making the case for a fuller engagement with “desistance” research in supporting this process. Thirdly, we examine who can and should be involved in conversations about EBP, arguing that both ex/offenders’ and practitioners’ voices need to be respected and heard in this debate

Lessons in learning gain: insights from a pilot project

‘Learning gain’ has become an increasingly prominent concept in debates about the effectiveness of higher education across OECD countries. In England, interest has been heightened by the Higher Education Funding Council for England (HEFCE)’s major research initiative on learning gain, launched in 2015, and by the new Teaching Excellence Framework which assesses learning and teaching and student outcomes. HEFCE’s novel research initiative has funded a set of experimental projects across the English higher education sector for the first time. This paper presents preliminary findings from one such project at the University of East Anglia (UEA). The project trials and evaluates three approaches to identifying and measuring learning gain using data from cohorts of students across different discipline areas during 2015–2016 and 2016–2017. It builds upon previous work carried out at UEA in developing self-efficacy assessments and applying concept inventories. Student marks provide a simple comparator as a third approach to measuring learning gain

Matrix Pencils and Entanglement Classification

In this paper, we study pure state entanglement in systems of dimension $2\otimes m\otimes n$. Two states are considered equivalent if they can be reversibly converted from one to the other with a nonzero probability using only local quantum resources and classical communication (SLOCC). We introduce a connection between entanglement manipulations in these systems and the well-studied theory of matrix pencils. All previous attempts to study general SLOCC equivalence in such systems have relied on somewhat contrived techniques which fail to reveal the elegant structure of the problem that can be seen from the matrix pencil approach. Based on this method, we report the first polynomial-time algorithm for deciding when two $2\otimes m\otimes n$ states are SLOCC equivalent. Besides recovering the previously known 26 distinct SLOCC equivalence classes in $2\otimes 3\otimes n$ systems, we also determine the hierarchy between these classes

The Hyperbolic Heisenberg and Sigma Models in (1+1)-dimensions

Hyperbolic versions of the integrable (1+1)-dimensional Heisenberg Ferromagnet and sigma models are discussed in the context of topological solutions classifiable by an integer `winding number'. Some explicit solutions are presented and the existence of certain classes of such winding solutions examined.Comment: 13 pages, 1 figure, Latex, personal style file included tensind.sty, Proof in section 3 altered, no changes to conclusion

The dispersive self-dual Einstein equations and the Toda lattice

The Boyer-Finley equation, or $SU(\infty)$-Toda equation is both a reduction of the self-dual Einstein equations and the dispersionlesslimit of the $2d$-Toda lattice equation. This suggests that there should be a dispersive version of the self-dual Einstein equation which both contains the Toda lattice equation and whose dispersionless limit is the familiar self-dual Einstein equation. Such a system is studied in this paper. The results are achieved by using a deformation, based on an associative $\star$-product, of the algebra $sdiff(\Sigma^2)$ used in the study of the undeformed, or dispersionless, equations.Comment: 11 pages, LaTeX. To appear: J. Phys.

Opening of a pseudogap in a quasi-two dimensional superconductor due to critical thermal fluctuations

We examine the role of the anisotropy of superconducting critical thermal fluctuations in the opening of a pseudogap in a quasi-two dimensional superconductor such as a cuprate-oxide high-temperature superconductor. When the anisotropy between planes and their perpendicular axis is large enough and its superconducting critical temperature T_c is high enough, the fluctuations are much developed in its critical region so that lifetime widths of quasiparticles are large and the energy dependence of the selfenergy deviates from that of Landau's normal Fermi liquids. A pseudogap opens in such a critical region because quasiparticle spectra around the chemical potential are swept away due to the large lifetime widths. The pseudogap never smoothly evolves into a superconducting gap; it starts to open at a temperature higher than T_c while the superconducting gap starts to open just at T_c. When T_c is rather low but the ratio of varepsilon_G(0)/k_BT_c, with varepsilon_G(0) the superconducting gap at T=0K and k_B the Boltzmann constant, is much larger than a value about 4 according to the mean-field theory, the pseudogap must be closing as temperature T approaches to the low T_c because thermal fluctuations become less developed as T decreases. Critical thermal fluctuations cannot cause the opening of a prominent pseudogap in an almost isotropic three dimensional superconductor, even if its T_c is high.Comment: 25 pages, 5 figures (14 subfigures

Necrotic tumor growth: an analytic approach

The present paper deals with a free boundary problem modeling the growth process of necrotic multi-layer tumors. We prove the existence of flat stationary solutions and determine the linearization of our model at such an equilibrium. Finally, we compute the solutions of the stationary linearized problem and comment on bifurcation.Comment: 14 pages, 3 figure

From 2D conformal to 4D self-dual theories: quaternionic analyticity

It is shown that self-dual theories generalize to four dimensions both the conformal and analytic aspects of two-dimensional conformal field theories. In the harmonic space language there appear several ways to extend complex analyticity (natural in two dimensions) to quaternionic analyticity (natural in four dimensions). To be analytic, conformal transformations should be realized on $CP^3$, which appears as the coset of the complexified conformal group modulo its maximal parabolic subgroup. In this language one visualizes the twistor correspondence of Penrose and Ward and consistently formulates the analyticity of Fueter.Comment: 24 pages, LaTe