Multipion States in Lattice QCD and the Charged-pion Condensate PDF Download
Are you looking for read ebook online? Search for your book and save it on your Kindle device, PC, phones or tablets. Download Multipion States in Lattice QCD and the Charged-pion Condensate PDF full book. Access full book title Multipion States in Lattice QCD and the Charged-pion Condensate by . Download full books in PDF and EPUB format.
Author: Publisher: ISBN: Category : Languages : en Pages : 14507
Book Description
The ground-state energies of systems containing up to 12 pi+'s in a spatial volume V~(2.5 fm)3 are computed in dynamical, mixed-action lattice QCD at a lattice spacing of ~0.125 fm for four different values of the light-quark masses. Clean signals are seen for each ground-state, allowing for a precise extraction of both the pi+pi+ scattering length and pi+pi+pi+ interaction from a correlated analysis of systems containing different numbers of pi+'s. This extraction of the pi+pi+ scattering length is consistent with that from the pi+pi+ system alone. The large number of systems studied here significantly strengthens the arguments presented in our earlier work and unambiguously demonstrates the presence of a low energy pi+pi+pi+ interaction. The equation of state of a pi+ gas is investigated using our numerical results and the density dependence of the isospin chemical potential for these systems agrees well with the theoretical expectations of leading order chiral perturbation theory.
Author: Publisher: ISBN: Category : Languages : en Pages : 14507
Book Description
The ground-state energies of systems containing up to 12 pi+'s in a spatial volume V~(2.5 fm)3 are computed in dynamical, mixed-action lattice QCD at a lattice spacing of ~0.125 fm for four different values of the light-quark masses. Clean signals are seen for each ground-state, allowing for a precise extraction of both the pi+pi+ scattering length and pi+pi+pi+ interaction from a correlated analysis of systems containing different numbers of pi+'s. This extraction of the pi+pi+ scattering length is consistent with that from the pi+pi+ system alone. The large number of systems studied here significantly strengthens the arguments presented in our earlier work and unambiguously demonstrates the presence of a low energy pi+pi+pi+ interaction. The equation of state of a pi+ gas is investigated using our numerical results and the density dependence of the isospin chemical potential for these systems agrees well with the theoretical expectations of leading order chiral perturbation theory.
Author: Publisher: ISBN: Category : Languages : en Pages : 54514
Book Description
Doi: http://dx.doi.org/10.1103/PhysRevD.78.054514 Kaon condensation may play an important role in the structure of hadronic matter at densities greater than that of nuclear matter, as exist in the interior of neutron stars. We present the results of the first lattice QCD calculation of kaon condensation obtained by studying systems containing up to twelve charged kaons. Surprisingly, the equation of state of the condensate is remarkably well reproduced by leading order chiral perturbation theory. We determine the three-kaon interaction from the multi-kaon systems and update our results for pion condensates.
Author: Publisher: ISBN: Category : Languages : en Pages : 5
Book Description
We simulate lattice QCD at a finite chemical potential [mu]{sub I} for isospin (I3) at zero and finite temperatures. At some [mu]{sub I} = [mu]c QCD has a second order transition with mean-field critical exponents to a state where (I3) is broken spontaneously by a charged pion condensate. Heating the system with [mu]{sub I}> [mu]{sub c} we find there is some temperature at which this condensate evaporates. This transition appears to be second order and mean-field at lower [mu]{sub I} values, and first order for [mu]{sub I} sufficiently large. We are determining the dependence of the finite temperature crossover T{sub c} on [mu]{sub I} for [mu]{sub I}
Author: Thibaut Métivet Publisher: ISBN: Category : Languages : en Pages : 0
Book Description
The formalism of Quantum Chromodynamics on the lattice (or Lattice QCD) allows to perform ab-initio non-perturbative studies of strong-interaction driven processes, as it provides both a covariant regularisation of the theory of QCD and a natural framework for numerical computations. In this work, after a review of the main features of QCD and a step-by-step presentation of our discretization of QCD on a lattice, we undertake detailed studies of two problems of hadronic physics: the phenomenon of resonant scattering and the structure of the nucleon. The lattice calculations are performed with the Budapest-Marseille-Wuppertal Collaboration's 2+1-flavour gauge configurations, which give access to a wide range of lattice spacings, volumes and quarks masses, thereby allowing to study the sensibility of our results on these parameters, and to perform a complete continuum extrapolation. These configurations include dynamical quarks, and use a clover-improved Wilson QCD action. To investigate the scattering of particles on the lattice, we set up a Lüscher analysis for the emblematic case of pion-pion scattering in the channel of the rho meson resonance. We analyse our data with a variational generalized eigenvalue method, and give an in-depth calculation of the scattering phase-shifts and the corresponding resonance parameters, with a full control of the systematic errors. Our results provide an important step for lattice studies of scattering states, as they are the first to be performed at the physical pion mass, where one can see the actual decay of the rho into two pions. The obtained rho meson parameters are in good agreement with the experimental values, and consistent with a weak pion mass dependence of the coupling between the rho and two pions. As for our probe of the structure of the nucleon, we present a complete extraction of the electroweak isovector form factors, with a comprehensive study of the electric charge squared radius and of the axial charge. Our analysis also feature data at the physical pion mass, which turns out to be crucial in order to perform safe extrapolations to the physical point, as the chiral perturbation theory predicts violent variations of these quantities near the massless-quarks point. Our calculation includes source and sink projections onto the nucleon state, as well as a combined fit method between the two-point and three-point correlation functions to control the contamination of our data by excited states. Although one would need more data to perform a high-accuracy determination of the nucleon radius and axial charge at the physical point with a relevant estimation of the systematic errors, the results we obtain are in good agreement with the experiment and suggest that the excited-state effects are under control. Our analysis also highlights that gauge configurations ensembles near the physical pion mass and with large volumes must be used in order to extract accurate information about the nucleon structure from lattice calculations.
Author: Fred Jegerlehner Publisher: Springer Science & Business Media ISBN: 3540726330 Category : Science Languages : en Pages : 433
Book Description
This book reviews the present state of knowledge of the anomalous magnetic moment a=(g-2)/2 of the muon. The muon anomalous magnetic moment is one of the most precisely measured quantities in elementary particle physics and provides one of the most stringent tests of relativistic quantum field theory as a fundamental theoretical framework. It allows for an extremely precise check of the standard model of elementary particles and of its limitations.
Author: Palash B. Pal Publisher: Taylor & Francis ISBN: 1482216981 Category : Science Languages : en Pages : 818
Book Description
For graduate students unfamiliar with particle physics, An Introductory Course of Particle Physics teaches the basic techniques and fundamental theories related to the subject. It gives students the competence to work out various properties of fundamental particles, such as scattering cross-section and lifetime. The book also gives a lucid summary of the main ideas involved. In giving students a taste of fundamental interactions among elementary particles, the author does not assume any prior knowledge of quantum field theory. He presents a brief introduction that supplies students with the necessary tools without seriously getting into the nitty-gritty of quantum field theory, and then explores advanced topics in detail. The book then discusses group theory, and in this case the author assumes that students are familiar with the basic definitions and properties of a group, and even SU(2) and its representations. With this foundation established, he goes on to discuss representations of continuous groups bigger than SU(2) in detail. The material is presented at a level that M.Sc. and Ph.D. students can understand, with exercises throughout the text at points at which performing the exercises would be most beneficial. Anyone teaching a one-semester course will probably have to choose from the topics covered, because this text also contains advanced material that might not be covered within a semester due to lack of time. Thus it provides the teaching tool with the flexibility to customize the course to suit your needs.
Author: 
Author: 
Author: 
Author: 
Author: 
Author: Thibaut Métivet
Author: 
Author: 
Author: Istvan Montvay
Author: Fred Jegerlehner
Author: Palash B. Pal