Prospects for observation of double parton scattering with four-muon final states at LHCb

We study the prospects for observing double parton scattering through four-muon final states, forming two opposite-sign muon pairs, in the LHCb experiment in pp collisions at 14 TeV centre of mass energy. We consider two special cases, namely double Drell-Yan and J/psi-pair production. The kinematic properties and prospects for observing these processes are discussed. We find that the production rate depends strongly on the origin of the four muons, while many kinematic properties can be used to help identify the presence of double parton scattering events.Comment: 22 pages, 12 figure

Profile of the U 5f magnetization in U/Fe multilayers

Recent calculations, concerning the magnetism of uranium in the U/Fe multilayer system have described the spatial dependence of the 5f polarization that might be expected. We have used the x-ray resonant magnetic reflectivity technique to obtain the profile of the induced uranium magnetic moment for selected U/Fe multilayer samples. This study extends the use of x-ray magnetic scattering for induced moment systems to the 5f actinide metals. The spatial dependence of the U magnetization shows that the predominant fraction of the polarization is present at the interfacial boundaries, decaying rapidly towards the center of the uranium layer, in good agreement with predictions.Comment: 7 pages, 6 figure

Total Hip Arthroplasty When Utilised in Young Adults Is a Cost-Effective Procedure:A 10-Year and Lifetime Cost-Utility Analysis

Purpose The primary aim of this study was to determine the cost-effectiveness of total hip arthroplasty (THA) in patients aged 25 years and under by calculating the cost per quality-adjusted life year (QALY) gained at 10 years post-operatively, and over the course of a lifetime. Secondary aims were to describe the change in health-related quality of life (HRQoL), Oxford hip score (OHS), and satisfaction in these patients. Methods From 2000 to 2016, 33 patients undergoing THA aged 25 and under had pre-operative and one-year post-operative EuroQol five-dimensions (EQ-5D) scores and OHS recorded prospectively. Post-operative change in EQ-5D allowed calculation of a health-utility score, which, when combined with life expectancy, gave total QALYs gained. Results The mean age was 20 years (range 13.3-24.9), with 23 females (72.7%). Mean number of QALYs gained was 21.1 (95% CI 14.1-28.2). Total lifetime cost per patient was £14641, giving a mean cost per QALY of £4183 at 10 years post-operatively, and £694 over the total remaining lifetime. Discounting total QALYs gained at a rate of 3.5% and 5% per remaining year of life expectancy increased the mean cost per QALY to £1652 and £2187, respectively. Mean pre- and post-operative EQ-5D index were 0.27 (SD 0.27) and 0.63 (SD 0.29), respectively (p=0.0001). Mean pre-operative and post-operative OHS was 37.5 (SD 7.9) and 19.7 (SD 6.94), respectively (p<0.00001). Conclusion THA remains a cost-effective intervention for patients aged 25 years and under. It is also associated with significant improvement in HRQoL, OHS, and high levels of patient satisfaction in this unique patient group

New Deterministic Algorithms for Solving Parity Games

We study parity games in which one of the two players controls only a small number $k$ of nodes and the other player controls the $n-k$ other nodes of the game. Our main result is a fixed-parameter algorithm that solves bipartite parity games in time $k^{O(\sqrt{k})}\cdot O(n^3)$, and general parity games in time $(p+k)^{O(\sqrt{k})} \cdot O(pnm)$, where $p$ is the number of distinct priorities and $m$ is the number of edges. For all games with $k = o(n)$ this improves the previously fastest algorithm by Jurdzi{\'n}ski, Paterson, and Zwick (SICOMP 2008). We also obtain novel kernelization results and an improved deterministic algorithm for graphs with small average degree

Dependency Tree Automata

Abstract. We introduce a new kind of tree automaton, a dependency tree automaton, that is suitable for deciding properties of classes of terms with binding. Two kinds of such automaton are defined, nondeterministic and alternating. We show that the nondeterministic automata have a decidable nonemptiness problem and leave as an open question whether this is true for the alternating version. The families of trees that both kinds recognise are closed under intersection and union. To illustrate the utility of the automata, we apply them to terms of simply typed lambda calculus and provide an automata-theoretic characterisation of solutions to the higher-order matching problem

The polarizability model for ferroelectricity in perovskite oxides

This article reviews the polarizability model and its applications to ferroelectric perovskite oxides. The motivation for the introduction of the model is discussed and nonlinear oxygen ion polarizability effects and their lattice dynamical implementation outlined. While a large part of this work is dedicated to results obtained within the self-consistent-phonon approximation (SPA), also nonlinear solutions of the model are handled which are of interest to the physics of relaxor ferroelectrics, domain wall motions, incommensurate phase transitions. The main emphasis is to compare the results of the model with experimental data and to predict novel phenomena.Comment: 55 pages, 35 figure