Sökning: "Lattice QCD"

Hittade 5 avhandlingar innehållade orden Lattice QCD.

  1. 1. Multi-Meson Dynamics in Chiral Perturbation Theory

    Författare :Mattias Sjö; Partikel- och kärnfysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Spridningsamplituder; Effektiv Fältteori; Spontant symmetribrott; Ickelinjära sigmamodellen; Kirala Lagrangianer; Hadronspektroskopi; Strukturer och Interaktioner; Gitter-QCD; Scattering amplitudes; Effective Field Theories; Spontaneous Symmetry Breaking; Nonlinear sigma model; Chiral Lagrangians; Hadronic Spectroscopy; Structure and Interactions; Lattice QCD;

    Sammanfattning : This thesis concerns scattering of light mesons in the case where the number of external particles exceeds four (that is, three or more particles in the initial or final state), calculated using chiral perturbation theory.This is both of theoretical interest in the study of scattering amplitudes, and relevant for systems of three or more pions simulated using lattice quantum chromodynamics. LÄS MER

  3. 2. From exotic superconductivity to QCD and back again searching things in common

    Författare :Egor Babaev; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Theoretical physics; Chrial symmetry; Pseudogap; vortices; knots; solitons; Teoretisk fysik; Physics; Fysik;

    Sammanfattning : This thesis is devoted largely to two new features which Particle Physics and Condensed Matter theory have in common. The first part of the thesis is a discussion of formation of phases precursory to the chiral phase transition in relativistic models with four-fermion interactions, considered as toy models for QCD. LÄS MER

  4. 3. Higher Order Calculations for Low Energy Precision Physics

    Författare :Nils Hermansson Truedsson; Teoretisk partikelfysik - Geonomgår omorganisation; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Effective Field Theory; Chiral Perturbation Theory; The Muon Anomalous Magnetic Moment; Lattice Gauge Theory; Finite Volume Effects; Fysicumarkivet A:2019:Hermansson; Effektiv fältteori; Kiral störningsräkning; Myonens anomala magnetiska moment; Gitter-gaugeteori; Ändlig-volymkorrektioner;

    Sammanfattning : This thesis concerns higher order calculations needed for precision physics in the low energy region of particlephysics. Of the four papers it contains, the first two introduce calculations at order p8 in the power countingof chiral perturbation theory, which is an effective field theory of QCD at low energies. LÄS MER

  5. 4. Twisted Loops and Models for Form-factors and the Muon g-2

    Författare :Johan Relefors; Teoretisk partikelfysik - Geonomgår omorganisation; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Chiral perturbation theory; Twisted boundary conditions; Phenomenological models; Muon g-2; Fysicumarkivet A:2016:Relefors;

    Sammanfattning : In this thesis we use effective field thory methods and models for low energy QCD in two different contexts. One is direct calculation of contributions to the anomalous magnetic moment of the muon, muon g-2. The other is estimates of systematic sources of uncertainty in lattice QCD simulations. The work is presented in five papers. LÄS MER

  7. 5. Meson Properties in Partially Quenched Effective Field Theory

    Författare :Niclas Danielsson; Matematisk fysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; statistical physics; gravitation; relativity; quantum mechanics; classical mechanics; Mathematical and general theoretical physics; Fysik; Chiral Perturbation Theory; masses; decay constants; Physics; electromagnetic interactions; Strong interactions; pseudoscalar mesons; thermodynamics; Matematisk och allmän teoretisk fysik; klassisk mekanik; kvantmekanik; relativitet; statistisk fysik; termodynamik;

    Sammanfattning : Mass corrections and decay constants for light mesons have been calculated in Partially Quenched Chiral Perturbation Theory. The calculations of the charged meson masses have been performed to third order, first for degenerate quark masses, and then, in a second project, for the general case. LÄS MER