Download or read book Quark hadron Duality in the t Hooft Model for Meson Weak Decays written by and published by . This book was released on 1998 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The authors compare the effects of different quark diagram topologies on the weak hadronic width of heavy-light mesons in the large N{sub c} limit. They enumerate the various topologies and show that the only one dominant (or even comparable) in powers of N{sub c} to the noninteracting spectator ''tree'' diagram is the ''annihilation'' diagram, in which the valence quark-antiquark pair annihilate weakly. They compute the amplitude for this diagram in the 't Hooft model (QCD in 1+1 spacetime dimensions with a large number of colors N{sub c}) at the hadronic level and compare to the Born term partonic level. They find that quark-hadron duality is not well satisfied, even after the application of a smearing procedure to the hadronic result. A number of interesting subtleties absent from the tree diagram case arise in the annihilation diagram case, and are described in detail.
Download or read book Explicit Quark hadron Duality in 1 1 Dimensions written by and published by . This book was released on 1998 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Explicit quark-hadron duality in the limit of heavy quark mass is studied using the 't Hooft model, where both partonic and hadronic amplitudes may be computed exactly. Results for weak decays of heavy mesons are presented for both standard spectator decays, where the duality limit is convincingly approached, and annihilation decays of the valence quark-antiquark pair, where the approach to asymptotic duality is much less precise.
Download or read book Pauli Interference in the t Hooft Model written by and published by . This book was released on 1999 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Pauli Interference in decays of heavy flavor mesons, a genuinely nonleptonic nonperturbative effect, is considered in the 't Hooft model. Analytic summation of the exclusive decay widths yields the same expression as obtained in the OPE-based approach. Threshold-related violations of local duality in PI are found to be suppressed. A novel case is identified where the OPE effect is completely saturated by a single final state.
Download or read book Quark Confinement and the Hadron Spectrum III written by Nathan Isgur and published by World Scientific. This book was released on 2000 with total page 384 pages. Available in PDF, EPUB and Kindle. Book excerpt: The confinement mechanism of the quarks in QCD is one of the most challenging and open problems in physics. Confinement is a nonperturbative phenomenon, and a definite way to handle it has not yet been found in field theory. There are lattice calculations that can produce the low-lying states of the spectrum and ?measure? many important physical quantities, but nevertheless the development of analytical techniques is of extreme importance for understanding the physics involved in confinement. In this respect it is important to test the results obtained directly from the theory (Bethe-Salpeter kernel, effective Hamiltonians, quark potential, etc.) on the spectrum, form factors and decays of bound states of quarks and gluons, and to relate them to the results of lattice theory.In this book, the question of the confinement mechanism is addressed; explanations in terms of monopoles, instantons and dyons are reviewed and the connection with duality is discussed.
Download or read book Precision Studies of Duality in the t Hooft Model written by and published by . This book was released on 2000 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The authors address numerical aspects of local quark-hadron duality using the example of the exactly solvable 't Hooft model, two-dimensional QCD with Nc?8. The primary focus of these studies is total semileptonic decay widths relevant for extracting (Vcb) and (Vub). They compare the exact channel-by-channel sum of exclusive modes to the corresponding rates obtained in the standard 1/mQ expansion arising from the Operator Product Expansion. An impressive agreement sets in unexpectedly early, immediately after the threshold for the first hadronic excitation in the final state. Yet even at higher energy release it is possible to discern the seeds of duality-violating oscillations. They find the ''Small Velocity'' sum rules to be exceptionally well saturated already by the first excited state. They also obtain a convincing degree of duality in the differential distributions and in an analogue of Re+e-(s). Finally, they discuss possible lessons for semileptonic decays of actual heavy quarks in QCD.
Download or read book Quark Confinement And The Hadron Spectrum Iii Jun 98 Usa written by Nathan Isgur and published by World Scientific. This book was released on 2000-06-27 with total page 384 pages. Available in PDF, EPUB and Kindle. Book excerpt: The confinement mechanism of the quarks in QCD is one of the most challenging and open problems in physics. Confinement is a nonperturbative phenomenon, and a definite way to handle it has not yet been found in field theory. There are lattice calculations that can produce the low-lying states of the spectrum and “measure” many important physical quantities, but nevertheless the development of analytical techniques is of extreme importance for understanding the physics involved in confinement. In this respect it is important to test the results obtained directly from the theory (Bethe-Salpeter kernel, effective Hamiltonians, quark potential, etc.) on the spectrum, form factors and decays of bound states of quarks and gluons, and to relate them to the results of lattice theory.In this book, the question of the confinement mechanism is addressed; explanations in terms of monopoles, instantons and dyons are reviewed and the connection with duality is discussed.
Download or read book Properties Of Hadron In Matter Proceedings Of The Aptctp Workshop On Astro hadron Physics In Honor Of Pro written by Gerald E Brown and published by World Scientific. This book was released on 1999-03-12 with total page 656 pages. Available in PDF, EPUB and Kindle. Book excerpt: This proceedings volume discusses recent developments in the physics of strongly interacting systems, with emphasis on matter under extreme conditions that are possibly encountered in astrophysical phenomena and relativistic heavy-ion collisions.
Download or read book Heavy Flavour Physics Theory and Experimental Results in Heavy Quark Physics written by C.T.H Davies and published by CRC Press. This book was released on 2019-03-29 with total page 414 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides a thorough introduction to the phenomenology of heavy flavour physics, those working on the B-factories, LHCb, BTeV, HERA and the Tevatron. It explains how heavy quark theory could be implemented on the lattice, and discusses the status of CP-violation in the neutral kaon system.
Download or read book Heavy Quark Physics written by Aneesh V. Manohar and published by Cambridge University Press. This book was released on 2023-07-31 with total page 205 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Quark Model and High Energy Collisions written by Vladimir Vladislavovich Anisovich and published by World Scientific. This book was released on 2004 with total page 547 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is an updated version of the book published in 1985. QCD-motivated, it gives a detailed description of hadron structure and soft interactions in the additive quark model, where hadrons are regarded as composite systems of dressed quarks.In the past decade it has become clear that nonperturbative QCD, responsible for soft hadronic processes, may differ rather drastically from perturbative QCD. The understanding of nonperturbative QCD requires a detailed investigation of the experiments and the theoretical approaches. Bearing this in mind, the book has been rewritten paying special attention to the interplay of soft hadronic collisions and the quark model. It is at the crossroads of these domains that peculiar features of strong QCD reveal themselves.The book discusses constituent quarks, diquarks, the massive effective gluons and the problem of scalar isoscalar mesons. The quark-gluonium classification of meson states is also given. Experimentally observed properties of hadrons are presented together with the corresponding theoretical interpretation in the framework of the composite hadron structure.The text includes a large theoretical part, which shows how to treat composite systems (including relativistic ones) with a technique based on spectral integration. This technique provides the possibility of handling hadrons as weakly bound systems of quarks and, at the same time, takes into account confinement.Attention is focused on the composite structure revealing itself in high energy hadron collisions. Fields of applicability of the additive quark model are discussed, as is colour screening in hadronic collisions at high and superhigh energies. Along with a detailed presentation of hadron-hadron collisions, a description of hadron-nucleus collisions is given.
Download or read book The Quark Confinement Model of Hadrons written by G.V Efimov and published by CRC Press. This book was released on 1993-01-01 with total page 196 pages. Available in PDF, EPUB and Kindle. Book excerpt: Filling the gap in the literature on low-energy quark models, The Quark Confinement Model of Hadrons investigates confinement effects in the low-energy regions of particle physics using the methods of nonlocal quantum field theory. It also elucidates their role in describing microscopic quantities that characterize hadron-hadron interactions. The authors present a quark confinement model to describe the low-energy physics of light hadrons. Hadrons are treated as collective colorless excitations of quark-gluon interactions while the quark confinement is to be provided by averaging over gluon backgrounds. The model is shown to reproduce the low-energy relations of chiral theory in the case of null momenta and, in addition, allow the researcher to obtain more sophisticated hadron characteristics, such as slope parameters and form factors. Presenting a unified view on a number of low-energy phenomena, The Quark Confinement Model of Hadrons enables an understanding of problems related to the treatment of large distances within quantum chromodynamics.
Download or read book Confined Quarks and Quark hadron Duality in Meson Physics written by V. V. Anisovič and published by . This book was released on 1994 with total page 60 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Acta Physica Polonica written by and published by . This book was released on 1998 with total page 796 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Meson Decays in a Quark Model written by and published by . This book was released on 1997 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A recent model of hadron states is extended to include meson decays. The authors find that the overall success of the model is quite good. Possible improvements to the model are suggested.
Download or read book Quark Hadron Duality and Scaling in Reduced QCD written by and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We introduce a generalization of 1+1 dimensional large N{sub c} QCD, which we refer to as ''reduced'' QCD, or rQCD. In this model gluons and quark momenta live in 1+1 dimensions only, but the quark spin and all other particles (leptons, and the photon) live in the full 1 + 3 dimensions. The bound states of quarks and antiquarks are identical to those originally described by 't Hooft (except that there are new transversely polarized states previously excluded), so the model is exactly soluble. However, significant differences arise when the model is applied to electromagnetic interactions. After reviewing the strongly interacting sector of the theory, we discuss deep inelastic scattering (DIS) in this model, and show that the new states with transverse polarization give the Callan-Gross relation and remove the pathological features of the original 1+1 dimensional description. We conclude that rQCD gives a satisfactory description of the phenomenology and provides a deep understanding of both duality and DIS.
Download or read book The Quark Structure of Hadrons written by Claude Amsler and published by Springer. This book was released on 2018-10-30 with total page 277 pages. Available in PDF, EPUB and Kindle. Book excerpt: Novel forms of matter, such as states made of gluons (glueballs), multiquark mesons or baryons and hybrid mesons are predicted by low energy QCD, for which several candidates have recently been identified. Searching for such exotic states of matter and studying their production and decay properties in detail has become a flourishing field at the experimental facilities now available or being built - e.g. BESIII in Beijing, BELLE II at SuperKEKB, GlueX at Jefferson Lab, PANDA at FAIR, J-PARC and in the upgraded LHC experiments, in particular LHCb. A modern primer in the field is required so as to both revive and update the teaching of a new generation of researchers in the field of QCD. These lectures on hadron spectroscopy are intended for Master and PhD students and have been originally developed for a course delivered at the Stefan Meyer Institute of the Austrian Academy of Sciences. They are phenomenologically oriented and intended as complementary material for basic courses in particle and nuclear physics. The book describes the spectra of light and heavy mesons and baryons, and introduces the fundamental properties based on symmetries. Further, it derives multiplet structures, mixing angle, decay coupling constants, magnetic moments of baryons, and predictions for multiquark states and compares these with suitable experimental data. Basic methods of calculating decay angular distributions and determining masses and widths of resonances are also presented. The appendices provide students and newcomers to the field with the necessary background information, and include a set of problems and solutions.
Download or read book Charming New Physics in Beautiful Processes written by Matthew John Kirk and published by Springer. This book was released on 2019-05-17 with total page 225 pages. Available in PDF, EPUB and Kindle. Book excerpt: This PhD thesis is dedicated to a subfield of elementary particle physics called “Flavour Physics”. The Standard Model of Particle Physics (SM) has been confirmed by thousands of experimental measurements with a high precision. But the SM leaves important questions open, like what is the nature of dark matter or what is the origin of the matter-antimatter asymmetry in the Universe. By comparing high precision Standard Model calculations with extremely precise measurements, one can find the first glimpses of the physics beyond the SM – currently we see the first hints of a potential breakdown of the SM in flavour observables. This can then be compared with purely theoretical considerations about new physics models, known as model building. Both precision calculations and model building are extremely specialised fields and this outstanding thesis contributes significantly to both topics within the field of Flavour Physics and sheds new light on the observed anomalies.
