488 research outputs found

    Gauge Theories in Particle Physics: A Practical Introduction, Fourth Edition - 2 Volume set

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    The fourth edition of this well-established, highly regarded two-volume set continues to provide a fundamental introduction to advanced particle physics while incorporating substantial new experimental results, especially in the areas of CP violation and neutrino oscillations. It offers an accessible and practical introduction to the three gauge theories included in the Standard Model of particle physics: quantum electrodynamics (QED), quantum chromodynamics (QCD), and the Glashow-Salam-Weinberg (GSW) electroweak theory. In the first volume, a new chapter on Lorentz transformations and discrete symmetries presents a simple treatment of Lorentz transformations of Dirac spinors. Along with updating experimental results, this edition also introduces Majorana fermions at an early stage, making the material suitable for a first course in relativistic quantum mechanics. Covering much of the experimental progress made in the last ten years, the second volume remains focused on the two non-Abelian quantum gauge field theories of the Standard Model: QCD and the GSW electroweak theory. A new chapter on CP violation and oscillation phenomena describes CP violation in B-meson decays as well as the main experiments that have led to our current knowledge of mass-squared differences and mixing angles for neutrinos. Exploring a new era in particle physics, this edition discusses the exciting discovery of a boson with properties consistent with those of the Standard Model Higgs boson. It also updates many other topics, including jet algorithms, lattice QCD, effective Lagrangians, and three-generation quark mixing and the CKM matrix. This revised and updated edition provides a self-contained pedagogical treatment of the subject, from relativistic quantum mechanics to the frontiers of the Standard Model. For each theory, the authors discuss the main conceptual points, detail many practical calculations of physical quantities from first principles, and compare these quantitative predictions with experimental results, helping readers improve both their calculation skills and physical insight

    Gauge Theories in Particle Physics: A Practical Introduction, Volume 2: Non-Abelian Gauge Theories

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    Volume 2 of this revised and updated edition provides an accessible and practical introduction to the two non-Abelian quantum gauge field theories of the Standard Model of particle physics: quantum chromodynamics (QCD) and the Glashow-Salam-Weinberg (GSW) electroweak theory.This volume covers much of the experimental progress made in the last ten

    Gauge Theories in Particle Physics: A Practical Introduction, Volume 1

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    Volume 1 of this revised and updated edition provides an accessible and practical introduction to the first gauge theory included in the Standard Model of particle physics: quantum electrodynamics (QED).The book includes self-contained presentations of electromagnetism as a gauge theory as well as relativistic quantum mechanics. It provides a uniq

    A regulatory governance perspective on health technology assessment (HTA) in France: the contextual mediation of common functional pressures

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    The new regulatory governance perspective has introduced several insights to the study of health technology assessment (HTA): it has broadened the scope for the analysis of HTA; it has provided a more sophisticated account of national diversity and the potential for cross-border policy learning; and, it has dissolved the distinction between HTA assessment and appraisal processes. In this paper, we undertake a qualitative study of the French process for HTA with a view to introducing a fourth insight: that the emergence and continuing function of national agencies for HTA follows a broadly evolutionary pattern in which contextual factors play an important mediating role. We demonstrate that the French process for HTA is characterised by distinctive institutions, processes and evidential requirements. Consistent with the mediating role of this divergent policy context, we argue that even initiatives for the harmonisation of national approaches to HTA are likely to meet with divergent national policy responses

    Electromagnetic navigation in total knee arthroplasty—a single center, randomized, single-blind study comparing the results with conventional techniques

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    We report on the results of a randomized study (n = 200) to compare total knee arthroplasty performed using conventional instrumentation or electromagnetic computer assisted surgical technique. 92% of navigated and 85% of conventional knees were implanted within ± 3° from neutral mechanical alignment; there was no statistically significant difference between these proportions. There was also no difference in femoral or tibial rotation assessed by CT scan. At 1 year follow up there was no statistical difference between the two groups in American Knee Society Score, Oxford Knee Scores, patient satisfaction, quality of life, hospital length of stay, complication rates or other adverse events. Tourniquet time in the navigated group was longer. Proving value for navigation in total knee arthroplasty surgery remains a challenge

    Spin-dependent Parton Distributions from Polarized Structure Function Data

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    In the past year, polarized deep inelastic scattering experiments at CERN and SLAC have obtained structure function measurements off proton, neutron and deuteron targets at a level of precision never before achieved. The measurements can be used to test the Bjorken and Ellis-Jaffe sum rules, and also to obtain information on the parton distributions in polarized nucleons. We perform a global leading-order QCD fit to the proton deep inelastic data in order to extract the spin-dependent parton distributions. By using parametric forms which are consistent with theoretical expectations at large and small xx, we find that the quark distributions are now rather well constrained. We assume that there is no significant intrinsic polarization of the strange quark sea. The data are then consistent with a modest amount of the proton's spin carried by the gluon, although the shape of the gluon distribution is not well constrained, and several qualitatively different shapes are suggested. The spin-dependent distributions we obtain can be used as input to phenomenological studies for future polarized hadron-hadron and lepton-hadron colliders.Comment: 23 pages, DTP/94/3

    Double π0\pi^0 Photoproduction off the Proton at Threshold

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    The reaction γp→π0π0p\gamma p \to \pi^0 \pi^0 p has been measured using the TAPS BaF2_2 calorimeter at the tagged photon facility of the Mainz Microtron accelerator. Chiral perturbation theory (ChPT) predicts that close to threshold this channel is significantly enhanced compared to double pion final states with charged pions. In contrast to other reaction channels, the lower order tree terms are strongly suppressed in 2π0\pi^0 photoproduction. The consequence is the dominance of pion loops in the 2π0\pi^0 channel close to threshold - a result that opens new prospects for the test of ChPT and in particular its inherent loop terms. The present measurement is the first which is sensitive enough for a conclusive comparison with the ChPT calculation and is in agreement with its prediction. The data also show good agreement with a calculation in the unitary chiral approach.Comment: Submitted to PL
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