bluuebunny/crossref_metadata_2025_split huggingface dataset:
Deeply bound pionic atoms
Authors: Toki H , Hirenzaki S , Matsuoka N 
Published: November 2023

Abstract
The structure and the formation of DBPAs have been studied theoretically by two groups extensively [1-13]. We follow here the papers by Toki et al. [2,6] to describe the theoretical methods employed in the analysis. We then discuss the experimental methods using direct reactions with hadrons. We would like to mention here that the DBPA states were discovered very recently at GSI using (d, 3He) reactions on 208Pb [14], after some indications of DBPAs were observed at TRIUMF with (n, d) reactions and at the Research Center for Nuclear Physics (RCNP) with (p,2He) reactions.
Neutron properties
Authors: Willis B T M , Carlile C J 
Published: November 2023

Abstract
Neutrons have a number of properties which distinguish them from X-rays. They have a weak interaction with matter and so have high penetrating capacity: walls of furnaces, cryostats, pressure vessels and others present little obstacle to the experimentalist. The atomic scattering amplitude is not linked to the number of shell electrons and so the magnitude of the interaction is different for the different isotopes of an element. The spin of the neutron interacts with the magnetic moments of unpaired electrons, allowing the study of magnetic materials. The energy and wavelength of thermal neutrons are comparable to the thermal energy and spacing of the atoms in solids; therefore, neutron scattering is the natural method for studying excitations, such as phonons and magnons, in crystals.
Neutron detection
Authors: Willis B T M , Carlile C J 
Published: November 2023

Abstract
The neutron is a very weak probe, and so neutron scattering does not unduly disturb the properties of the sample under investigation. From the point of view of scattering theory this is a significant advantage, as it allows us to use the Born approximation (whereby the scattering process is treated by first-order perturbation theory) in describing the neutron–nucleus interaction. However, the weakness of its interaction with matter also renders neutrons difficult to detect directly. Thermal neutrons produce negligible ionization and they can only be detected by the production of secondary ionization arising after neutron absorption. The absorption process leads to the formation of a compound nucleus, which decays either by the emission of a gamma ray or by a splitting of the compound nucleus into two charged nuclei. In neither case the energy of the incident neutron can be measured directly, as the absorption reactions are strongly exothermic with the release of several MeV of energy.
Polarized neutrons and magnetic neutron diffraction
Authors: Willis B T M , Carlile C J 
Published: November 2023

Abstract
Atoms such as iron, cobalt, manganese and nickel, in the first transition series of elements, have incomplete 3d electronic shells with unpaired electrons. These unpaired electrons give rise to a resultant magnetic moment, and the interaction of this atomic moment with the magnetic moment of the neutron gives rise to magnetic neutron scattering. In this chapter, we shall be concerned with the magnetic scattering of polarized neutron beams by magnetic materials. Magnetic neutron scattering is always accompanied by nuclear neutron scattering, as described in Chapter 7.
Small-angle neutron scattering
Authors: Willis B T M , Carlile C J 
Published: November 2023

Abstract
The theory and practice of small-angle X-ray scattering (SAXS) dates back to the 1930s and is well described in the classic book of Guinier and Fournet (1955). Small-angle neutron scattering (SANS) came much later. It was not until the early 1970s, when position-sensitive detectors on cold neutron guides became available, that systematic studies began using small-angle neutron scattering, but after this relatively late start the technique rapidly became one of the most popular and productive of all neutron scattering methods. SANS has been applied to a very wide range of problems, including the study of polymer conformations and morphology, the study of biological structures, the characterization of voids and precipitates in alloys, and the study of flux-line lattices in superconducting materials. The technique of ‘contrast variation’ is largely responsible for the success of SANS, especially in the study of soft condensed matter and biological systems. There are over 30 SANS instruments in operation worldwide at both reactor and spallation sources. In spite of an apparent wealth of instruments, the demand for beam time considerably outstrips the time available.
Neutron optics
Authors: Willis B T M , Carlile C J 
Published: November 2023

Abstract
Neutron optics refers to phenomena which arise from the interference between the incident and the scattered neutron waves. This is in contrast to the topics in earlier chapters of this book, where we have been concerned with interference between the scattered waves alone. The wave Halban and Preiswerk (1936) and by Mitchell and Powers (1936) using ‘white’ neutrons from a radium–beryllium source, and more convincingly by Zeilinger et al. (1988) using monochromatic neutrons from a reactor source. The subject of neutron optics itself began with the work of Fermi and Zinn (1946), who demonstrated the mirror reflection of a collimated beam of thermal neutrons. Since then nearly all the classical optical phenomena of reflection, refraction and interference have been shown to occur with neutrons.
Introduction
Authors: Dendy R O 
Published: November 2023

Abstract
The solid, liquid, and gaseous states of matter which occur at the surface of our planet are not typical of matter in the universe at large. Most of the visible matter in the universe exists as plasma, whereas lightning and the aurora are the only natural manifestations of the plasma state on Earth. In a plasma, the energy of the particles is so great that the electric forces which bind the atomic nucleus to its electrons are overcome. One might think of the resulting assembly of positively and negatively charged particles as a gas, but the waves that occur in it have much in common with waves in electrically conducting solids, and its bulk behavior is best described using terminology and equations developed for fluids: hence the fact that plasma is referred to as the fourth state of matter. For these reasons, when studying plasma physics, one often needs to rearrange and reapply concepts already acquired elsewhere, rather than deal with topics that are unfamiliar.
Early Developments
Authors: Luchini P , Motz H 
Published: November 2023

Abstract
An undulator is a device for generating electromagnetic radiation in a narrow spectral interval at frequencies ranging from radio or millimetre waves to X-rays. This is achieved by letting an electron beam with energy ranging from 1 MeV, say, to 1000 MeV pass through an array of magnets. If the device is placed into an optical resonator with mirrors at both ends, coherent radiation may be produced. By analogy with conventional lasers, it is then called a Free-electron Laser (FEL) (this term was introduced by Madey 1971a, b), although its manner of functioning is rather different from that of atomic or molecular lasing media.
Small-Signal, Small-Gain Free-Electron Laser
Authors: Luchini P , Motz H 
Published: November 2023

Abstract
When an electromagnetic wave of approximately the same frequency as the spontaneous undulator emission is driven through the undulator simultaneously with the electron beam, an interaction between the beam and the wave takes place which can lead to a noticeable exchange of energy. In this case the undulator becomes a coherent electromagnetic amplifier capable of working from microwaves to visible and shorter than visible wavelengths, and takes on the name of Free-Electron Laser (FEL).
Rare Earth Magnetism
Authors: Jensen Jens , Mackintosh Allan R 
Published: November 2023

Abstract
The aim of the authors in this monograph has been to present a general review of the magnetic properties of the rare earth metals, and a comprehensive, unified, and coherent account of the magnetic structures and excitations. These both reflect the nature of the fundamental interactions, and determine many of the characteristic properties of the metals. The authors have tried to concentrate on the essential principles and their applications to typical examples, generally restricting the discussion to the pure elements and considering alloys and compounds only when they are necessary to illuminate particular topics. Both authors have been involved for some time in the effort that has been made in Denmark to study, both theoretically and experimentally, the magnetic structures and especially the excitations in the rare earths. This account of the subject represents the results of their experience, and it is has been written in the hope that it will be useful not only to those who have a special interest in rare earth magnetism, but also to a wider audience who wish to learn something about the techniques and achievements of modern research in magnetism.
Magnetic Scattering Of Neutrons
Authors: Jensen Jens , Mackintosh Allan R 
Published: November 2023

Abstract
The scattering of low-energy neutrons provides an extremely powerful experimental technique for studying the properties of solids. The neutron has a number of special characteristics, on which its utility as a tool for examining magnetic materials depends. Because it is a neutral particle, it can penetrate deeply into most crystals, interacting through its magnetic moment with the electronic moments strongly enough to be measurably scattered, but without disturbing the magnetic system too severely. As a consequence, the great majority of neutrons participate in at most one scattering event, and they sense the properties of the unperturbed crystal. Thermal neutrons, with energies of the order of 25 meV, corresponding to wavelengths of the order of 2 Å, match both the interatomic spacings and the energies and momenta of the magnetic excitations, and are generated with adequate intensity by research reactors. Cold neutrons, with energies around 5 meV and wavelengths about 4Å, which are emitted from cooled moderators in reactors, may be even more ideally suited for studying the spatial arrangement and the dynamics of the magnetic moments.
Spin Waves In Periodic Structures
Authors: Jensen Jens , Mackintosh Allan R 
Published: November 2023

Abstract
Because of the modification of the translational symmetry, the spin waves in modulated magnetic structures display certain interesting aspects which are not shared by the simple ferromagnetic structure. However, this same feature makes their experimental study considerably more difficult, and the results which have been obtained on such systems are still relatively sparse. This chapter is correspondingly short, and in its two sections we distinguish between structures incommensurable with the lattice periodicity, when the translational symmetry in the direction of the wave-vector is, in principle, destroyed, and commensurable structures, in which this symmetry is only modified, though possibly quite drastically.
Calculational Methods for Quantum Electrodynamics
Authors: Pike frs E R , Sarkar Sarben 
Published: November 2023

Abstract
In the previous chapters we have developed the general structure of quantum electrodynamics. It is now necessary to give detailed rules for calculating processes of interest. Our use of the path integral for this purpose is mainly due to Feynman. The method that we will present is perturbation theory and also is widely applicable to theories other than quantum electrodynamics.
Par Tially Attractive Chains: Experimental Results
Authors: Cloizeaux Jacques des , Jannink Gerard 
Published: November 2023

Abstract
The behaviour of polymer solutions at various temperatures shows the existence of a demixtion phenomenon similar to that observed with binary mixtures of small molecules. Moreover, specific properties have been noted, characterizing the polymer state in poor solvent, and the progressive collapse of chains in dilute solutions when the temperature is lowered.
The Ubiquitous Photon
Authors: Gastmans R , Wu Tai Tsun 
Published: November 2023

Abstract
The authors' aim in this book is to give a pedagogical introduction to the helicity method, illustrated by many examples, and to summarize some ten years of research on the subject. Only some degree of familiarity with Feynman diagrams and Dirac algebra is required from the reader. The book also provides an extensive list of helicity amplitudes and cross-sections for many of the most important QED and QCD processes at high energies, some being new and not available in the literature previously.
Introduction
Authors: Gastmans R , Wu Tai Tsun 
Published: November 2023

Abstract
With energy galore, one can explore proton’s core more and more. Of all fundamental interactions in nature, the electromagnetic interactions between charged particles were the first to be studied extensively. The development of renormalized perturbation theory by Tomonaga, Schwinger, Feynman and Dyson [1] in the late 1940’s made quantum electrodynamics (QED) into an extremely successful theory which yielded many very precise predictions which were repeatedly confirmed by experiment, two prominent examples being the Lamb shift [2] and the anomalous magnetic moments of the electron and the muon [3]. QED, a relativistic quantum field theory based on an Abelian gauge symmetry, became the prototype field theory for all other interactions.
Helicity states
Authors: Gastmans R , Wu Tai Tsun 
Published: November 2023

Abstract
A deep emotion comes from true devotion to the right notion of spin in motion. In the following chapters, we shall only work in the high energy limit, which means that we shall neglect the fermion masses. Later on, in Chapter 7, we shall present the modifications to the helicity method which are necessary when the finiteness of the fermion mass has to be considered. For massless fermions, helicity states are Lorentz invariant notions. It is the aim of this book to show how much easier it is to calculate first the helicity amplitudes for a given process and to add their squared absolute values to obtain the cross section rather than following the procedures of Chapter 2. Of course, in Chapter 2, we only treated simple examples, for which the summation of |M|2 over the polarization states was not such a tremendous amount of work. However, when a process is described by n Feynman diagrams, it amounts to writing down n(n + 1)/2 traces. In the case of e+e- →e+e- γ, γ, we have 40 Feynman diagrams, and, if we include Z-exchange, this number increases to n = 80.
Single Bremsstrahlung in QCD
Authors: Gastmans R , Wu Tai Tsun 
Published: November 2023

Abstract
Color is a complication for gluon radiation:Its nicest implication is jet fragmentation. We now want to apply the helicity amplitude method for the calculation of QCD processes. Compared to QED calculations, there are three major sources of complications:There is a complication due to the appearance in the Feynman diagrams of color matrices or SU(3) structure constants. We shall see that a good choice for the polarization vectors of the gluons has the net result that one or more Feynman diagrams can be made to vanish. In this way, the helicity amplitude method reduces the amount of color algebra one has to perform to obtain cross section formulae.
Finite Mass Effects
Authors: Gastmans R , Wu Tai Tsun 
Published: November 2023

Abstract
The mere neglect of a mass effect is quite suspect and often not correct. In the previous chapters, we developed a general formalism for calculating multiple bremsstrahlung in gauge theories at high energies. By considering the limit of vanishing fermion masses, we were able to obtain simple expressions for the various helicity amplitudes. For high energy processes, the massless fermion limit is a good approximation unless nearly collinear particle configurations are encountered. In these kinematical situations, finite mass corrections have to be introduced for a correct description of the process.
Summary of QED formulae
Authors: Gastmans R , Wu Tai Tsun 
Published: November 2023

Abstract
All the following formulae are presented in the centre-of-mass system, with total energy denoted by 2E. Unless otherwise stated, we take the positive The indication m = 0 in the section headings implies that, throughout the section, we neglect the effects of a finite electron and/or muon mass. Consequently, the formulae are not valid in certain kinematical configurations. For a discussion of the ranges of validity of the approximation, we refer to Section 3. 4. Alternatively, the indication m ≠0 implies that the formulae in the section are valid to leading order in the fermion masses.
Beamstrahlung
Authors: Gastmans R , Wu Tai Tsun 
Published: November 2023

Abstract
Photons mediate,but electrons radiate:The loss of counting rate makes people fulminate. In this book, the helicity method is applied to a variety of processes. These processes are conveniently described in terms of Feynman diagrams, and as a result all formulae obtained so far, including those of Chapters 9 and 10, are each proportional to powers of the relevant coupling constants. Such applications of the helicity method are by now completely understood, although the calculations remain to be worked out for processes involving more particles, and further simplifications can be achieved in some cases.
Outlook
Authors: Gastmans R , Wu Tai Tsun 
Published: November 2023

Abstract
The use of helicity is not an eccentricity:It is pure simplicity which brings felicity. The ubiquity of the photon is a well-known fact in particle physics. Photons are necessarily present whenever charged particles take part in a process. The same is true for gluons when strongly interacting particles collide or decay. Photons and gluons being the carriers of the electromagneticforce and the strong force, they play a fundamental role in particle physics and their ubiquity only underscores this fact. It is therefore essential to study carefully the processes in which they take part. To understand their behaviour is to understand two fundamental forces in nature and the helicity method is a key ingredient in this exploration.We hope that, by now, the reader is convinced that the helicity method is an efficient way for obtaining cross section formulae in the high-energy limit. Nevertheless, we learn from the examples studied in the previous chapters that the final result of the calculation is often much simpler than the intermediate formulae which had to be worked out. This is because the starting point of the calculation usually consists of many Feynman diagrams. As a result, we strongly suspect that there is still room for improvement in the helicity method.
Statistical Physics of Fracture and Breakdown in Disordered Systems
Authors: Chakrabarti Bikas K , Gilles Benguigui L 
Published: November 2023

Abstract
Under extreme conditions the mechanical or electrical properties of solids tend to be destabilized and failure or breakdown occurs. In practice these instabilities in the solid often nucleate or spread from disorders in the structure of the solid. This book investigates the modelling of such failure and breakdown processes. The basic principles are illuminated with a large number of computer simulations and laboratory simulations or `table top' experiments. Three particular case studies of failure are presented: electrical failures like fuse and dielectric breakdown; mechanical fracture; and earthquakes as an example of dynamic failure.
Electrical Breakdown in Disordered Solids
Authors: Chakrabarti Bikas K , Gilles Benguigui L 
Published: November 2023

Abstract
In this chapter we shall begin with the problems associated with failures in disordered solids under the influence of an electric field, because this kind of failure is simpler than the mechanical failure or fracture. However, all the cases of failure present some common features, so that the study of electric failures will provide a convenient framework for introducing several important concepts.
Entangled polymer dynamics
Authors: Rubinstein Michael , Colby Ralph H 
Published: November 2023

Abstract
The Edwards tube model of polymer entanglements was already discussed in Section 7.3.1. The topological constraints imposed by neighbouring chains on a given chain restrict its motion to a tube-like region (see Fig. 7.10) called the confining tube. The motion of the chain along the contour of the tube (the primitive path) is unhindered by topological interactions. Displacement of monomers in the direction perpendicular to the primitive path is restricted by surrounding chains to an average distance a, called the tube diameter.
The development of an evidence-based approach to tackling health inequalities in Britain
Authors: Kelly Michael P 
Published: November 2023

Abstract
In Britain there has been a profound shift in the way that health inequalities have been defined and tackled, politically and scientifically, over the last three decades. The approach has altered from being an interesting academic problem of somewhat worthy concern, to becoming highly politicized and then demonized and, most recently, to being one of the key targets for an evidence-based approach to policy.
What Works for Children
Authors: Liabo Kristin , Frost Sarah , McNeish Diana , Sheldon, Trevor , Roberts Helen 
Published: November 2023

Abstract
Following the UK Government’s guidance that services be based on the best evidence of what works (Department of Health 1998), various initiatives tasked with getting research into practice have emerged in health and social care (CEBSS 2003; NICE 2005; Research in Practice 2005). Research evidence indicates that interventions in early childhood can make a difference to inequalities and other important outcomes in later life (Roberts 1997, 2000; Hertzman and Power 2004), and Government programmes have increasingly paid attention to this (Glass 1999, 2001).
The National Institute for Health and Clinical Excellence
Authors: Littlejohns Peter 
Published: November 2023

Abstract
The National Institute for Clinical Excellence (NICE) was established in 1999 to provide guidance to the National Health Service (NHS) on the clinical and cost effectiveness of health care interventions. During its first 6 years NICE produced 87 appraisals (with 54 in development), 37 clinical guidelines (with 42 in development), and 112 interventional procedures (with 61 in development). On 1 April 2005 the National Institute for Health and Clinical Excellence (also to be called NICE) was established by the transfer of the functions of the Health Development Agency to the National Institute for Clinical Excellence.
Evidence, policy, and practice: developing collaborative approaches in Scotland
Authors: Wimbush Erica , Harper Helen , Wight Daniel , Gruer Laurence , Lowther Matthew , Gordon, Jackie , Fraser Shirley 
Published: November 2023

Abstract
Over the last century the health of the people of Scotland has dramatically improved. The eradication of infectious diseases, the improvement in living conditions and nutrition, and the creation of the National Health Service (NHS) have all contributed to significant reductions in infant mortality rates and the opportunity of a disease-free life for most people. However, the rate of improvement in life expectancy since the mid-twentieth century has been slower in Scotland than in other parts of the UK and Europe (Leon et al. 2002).