Prospects for Discovering Supersymmetry at the LHC

Supersymmetry is one of the best-motivated candidates for physics beyond the Standard Model that might be discovered at the LHC. There are many reasons to expect that it may appear at the TeV scale, in particular because it provides a natural cold dark matter candidate. The apparent discrepancy between the experimental measurement of g_mu - 2 and the Standard model value calculated using low-energy e+ e- data favours relatively light sparticles accessible to the LHC. A global likelihood analysis including this, other electroweak precision observables and B-decay observables suggests that the LHC might be able to discover supersymmetry with 1/fb or less of integrated luminosity. The LHC should be able to discover supersymmetry via the classic missing-energy signature, or in alternative phenomenological scenarios. The prospects for discovering supersymmetry at the LHC look very good.Comment: 8 pages, 11 figure

Charge asymmetry in W + jets production at the LHC

The charge asymmetry in W + jets production at the LHC can serve to calibrate the presence of New Physics contributions. We study the ratio {\sigma}(W^+ + n jets)/{\sigma}(W^- + n jets) in the Standard Model for n <= 4, paying particular attention to the uncertainty in the prediction from higher-order perturbative corrections and uncertainties in parton distribution functions. We show that these uncertainties are generally of order a few percent, making the experimental measurement of the charge asymmetry ratio a particularly useful diagnostic tool for New Physics contributions.Comment: 13 pages, 7 figures. Reference added. Slightly modified tex

Soft sphere model for electron correlation and scattering in the atomistic modelling of semiconductor devices

The atomistic modelling of silicon MOSFET devices becomes essential at deep sub-micron scales when it is no longer possible to represent the charged impurities by a continuous charge distribution with a determined doping density. Instead the spatial distribution and the actual number of dopants must be treated as discrete random variables. The present paper addresses the issue of modelling the dynamics of discrete carrier flow in a semiconductor device utilising a simple model of the carrier-carrier scattering and carrier-fixed impurity scattering which is suitable for efficient simulations of large ensembles of devices

Efficient hole transport model in warped bands for use in the simulation of Si/SiGe MOSFETs

An analytical geometric model for the valence band in strained and relaxed Si1-xGex is presented, which shows good agreement with a 6-band k·p analysis of the valence band. The geometric model allows us to define an effective mass tensor for the warped valence band structure. The model also has applications in the study of III-V semiconductors, and could aid in the interpretation of cyclotron resonance experiments in these bands. A warped three-band Monte Carlo simulation has been developed based on this model making use of the efficient calculation of trajectory dynamics that is made possible through the use of such a model. The calculated transport characteristics show good agreement with the available experimental data

Noncanonical quantization of gravity. II. Constraints and the physical Hilbert space

The program of quantizing the gravitational field with the help of affine field variables is continued. For completeness, a review of the selection criteria that singles out the affine fields, the alternative treatment of constraints, and the choice of the initial (before imposition of the constraints) ultralocal representation of the field operators is initially presented. As analogous examples demonstrate, the introduction and enforcement of the gravitational constraints will cause sufficient changes in the operator representations so that all vestiges of the initial ultralocal field operator representation disappear. To achieve this introduction and enforcement of the constraints, a well characterized phase space functional integral representation for the reproducing kernel of a suitably regularized physical Hilbert space is developed and extensively analyzed.Comment: LaTeX, 42 pages, no figure

Nonequilibrium hole transport in deep sub-micron well-tempered Si p-MOSFETs

Using 2D full-band MC simulations the authors study nonequilibrium transport effects and the performance potential of well tempered Si p-channel MOSFETs covering gate lengths ranging from 90nm to 25nm. By comparing MC simulations with carefully calibrated drift diffusion (DD) simulations of the same devices, they provide a quantitative estimate of the importance and the influence of nonequilibrium transport on the device performance

Orthogonal Wavelets via Filter Banks: Theory and Applications

Wavelets are used in many applications, including image processing, signal analysis and seismology. The critical problem is the representation of a signal using a small number of computable functions, such that it is represented in a concise and computationally efficient form. It is shown that wavelets are closely related to filter banks (sub band filtering) and that there is a direct analogy between multiresolution analysis in continuous time and a filter bank in discrete time. This provides a clear physical interpretation of the approximation and detail spaces of multiresolution analysis in terms of the frequency bands of a signal. Only orthogonal wavelets, which are derived from orthogonal filter banks, are discussed. Several examples and applications are considered

A case analysis of optical fibre connection

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Beyond the "common context" : the production and reading of the Bridgewater Treatises

The Bridgewater Treatises were among the most widely circulated books of science in early nineteenth-century Britain, yet little is known of their contemporary readership. Drawing on the new history of the book, this essay examines the .. "communication circuit" in which the series was produced and read, exploring some of the processes that shaped the meanings the books possessed for their original readers. In so doing, it seeks to go beyond the standard interpretation of the Bridgewater Treatises as contributing to a "common context" for debate among the social and cultural elite. Instead, the essay demonstrates the wide circulation of the series among many classes of readers and shows that consideration of the distinctive meanings with which the books were invested by readers in divergent cultural groups serves to elucidate the contested meaning of science in the period. It is argued that by thus taking seriously the agency of all those involved in the communication circuit, including readers as well as authors and publishers, this approach supersedes the increasingly unworkable analytical category of "popular science.

Introduction [BJHS special section: book history and the sciences]

The expanding interest in book history over recent years has heralded the coming together of an interdisciplinary research community drawing scholars from a variety of literary, historical and cultural studies. Moreover, with a growing body of literature, the field is becoming increasingly visible on a wider scale, not least through the existence of the Society for the History of Authorship, Readership and Publishing (SHARP), with its newly founded journal Book History. Within the history of science, however, there remains not a little scepticism concerning the practical value of such an approach. It is often dismissed as an intellectual fad or as an enterprise which is illuminating but ultimately peripheral, rather than being valued as an approach which can offer major new insights within the field. This is no doubt in part because much of the most innovative work in history of science over recent years has been carried out by historians anxious to get away from an earlier overemphasis on printed sources. Eager to correct a profoundly unsocial history of ideas, usually rooted in texts, historians have looked increasingly to both the practices and the material culture of science. In such a context, a renewed focus on the history of books sometimes seems like a retrograde step, especially given the common misidentification of ‘books’ with ‘texts’. On the contrary, however, it is just such a twin emphasis on practices and material culture which also characterizes the new book history. Indeed, to the question ‘what is book history for?’ we might answer that its object is to reintroduce social actors, engaged in a variety of practices with respect to material objects, into a history in which books have too often been understood merely as disembodied texts, the meaning of which is defined by singular, uniquely creative authors, and is transparent to readers