Author: Y. KuramashiPublisher:
ISBN:
Category :
Languages : en
Pages : 17
Book Description
Lattice QCD Calculation in Full Pion Scattering Lengths
Author: Y. KuramashiLattice QCD Calculation of Hadron Scattering Lengths
Author: Y. KuramashiPion Kaon Scattering in Full QCD with Domain Wall Valence Quarks
Author: Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
We calculate the [pi]K+ scattering length at pion masses of m{sub [pi]} H"290, 350, 490 and 600 MeV in fully-dynamical lattice QCD with domain-wall valence quarks and rooted staggered sea quarks. The lattice data, analyzed at next-to-leading order in chiral perturbation theory, allows an extraction of the full piK scattering amplitude at threshold. Extrapolating to the physical point gives m{sub [pi]} [alpha]{sub 3/2} = -0.0574 ± 0.0016{sub -0.0058}{sup +0.0024} and m{sub [pi]} [alpha]{sub 1/2} = 0.1725 ± 0.0017{sub -0.0156}{sup +0.0023} for the I = 3/2 and I = 1/2 scattering lengths, respectively, where the first error is statistical and the second error is an estimate of the systematic error due to truncation of the chiral expansion.
Lattice QCD Calculation of Flavor Singlet Matrix Elements and N - N Scattering Lengths
Author: Yoshinobu KuramashiLattice QCD at the Physical Point
Author: Thibaut MétivetPublisher:
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.
New Developments in Lattice QCD
Author: Masanori OkawaHadronic Interactions from Lattice QCD.
Author: Konstantinos OrginosPublisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
In this talk I discuss a few recent results on lattice calculations of scattering lengths in hadronic processes. In particular, I present the scattering length of the pion-pion scattering in the I=2 channel and the nucleon-nucleon {sup 1}S{sub 0} channel and {sup 3}S{sub 1}-{sup 3}D{sub 1} coupled channels.
Chiral Dynamics 2006
Author: Mohammad W. AhmedPublisher: World Scientific
ISBN: 9812790802
Category : Science
Languages : en
Pages : 477
Book Description
Chiral Dynamics 2006 is the 5th International Workshop which examines the implications and the development of an approximate low-energy solution to the QCD Lagrangian based upon Chiral Symmetry. Advances in theory and experiment are presented in 20 plenary session papers along with more than one-hundred papers, including summaries, from the three working groups. Sample Chapter(s). Part 1.1: Opening Remarks: Experimental Tests of Chiral Symmetry Breaking (311 KB). Contents: Some Recent Developments in Chiral Perturbation Theory (U-G Meiner); Recent Results from HAPPEX (R Michaels); Kaon Physics: Recent Experimental Progress (M Moulson); Recent KTeV Results on Radiative Kaon Decays (M C Ronquest); Partially Quenched CHPT Results to Two Loops (J Bijnens); Finite Volume Effects: Lattice Meets CHPT (G Schierholz); Quark Mass Dependence of LECs in the Two-Flavour Sector (M Schmid); Leading Chiral Logarithms from Unitarity, Analyticity and the Roy Equations (A Fuhrer); Power Counting in Nuclear Chiral Effective Field Theory (U van Kolck); The Challenge of Calculating Baryon-Baryon Scattering from Lattice QCD (S R Beane); Few-Body Studies at KVI (J G Messchendorp); Compton Scattering on HE-3 (D Choudhury); Lattice Discretization Errors in Chiral Effective Field Theories (B C Tiburzi); Uncertainty Bands for Chiral Extrapolations (B U Musch); and other papers. Readership: Graduate students and academics in nuclear physics.
Modern Perspectives in Lattice QCD: Quantum Field Theory and High Performance Computing
Author: Laurent LellouchPublisher: Oxford University Press
ISBN: 0199691606
Category : Mathematics
Languages : en
Pages : 756
Book Description
The aim of the book is to familiarize the new generation of PhD students and postdoctoral fellows with the principles and methods of modern lattice field theory, which aims to resolve fundamental, non-perturbative questions about QCD without uncontrolled approximations.
Author: