Sökning: "low-energy QCD"

Visar resultat 1 - 5 av 6 uppsatser innehållade orden low-energy QCD.

1. 1. The last unknown leading order low-energy constant of chiral perturbation theory

   Master-uppsats, Uppsala universitet/Kärnfysik

   Författare :Magnus Bertilsson; [2024]
   Nyckelord :QCD; Form factors; Vector form factors; Chiral perturbation theory; Hadrons; Hadron physics; hyperon decay; semileptonic decay;

   Sammanfattning : .... LÄS MER

3. 2. Studies of the axial-vector transition form factors of the process Ω− → W−Ξ0 in chiral perturbation theory

   Master-uppsats, Uppsala universitet/Kärnfysik

   Författare :Hélène De Munck; [2023]
   Nyckelord :Transition form Factors; Next-to-next-to-leading order; chiral perturbation theory; axial-vector; Ω− → W−Ξ0;

   Sammanfattning : This work is included in a broader research of the hadron theory group of Uppsala University and its collaborators tackling the quest for an understanding of the quark distribution inside hadrons by joining threedifferent approaches of QCD namely chiral perturbation theory, dispersion theory and lattice QCD. This thesis contributes by computing in chiral perturbation theory, the quark-masses dependence of form factors. LÄS MER

4. 3. On the vector transition form factors in the Ω- → Ξ0 W- decay

   Master-uppsats, Uppsala universitet/Kärnfysik

   Författare :Magnus Bertilsson; [2023]
   Nyckelord :QCD; Form factors; Vector form factors; Chiral perturbation theory; One-loop diagrams; Hadrons; Hadron physics; Hyperon decay; Hadron structure;

   Sammanfattning : To learn more about the structure of hadrons we study form factors. In the semi-leptonic decay Ω- → Ξ0W- two types of form factors arise namely the vector and axial-vector transition form factors. LÄS MER

5. 4. Fitting the pion and kaon mass and decay constant to lattice data

   Kandidat-uppsats, Lunds universitet/Teoretisk partikelfysik - Geonomgår omorganisation

   Författare :Hector Tiblom; [2021]
   Nyckelord :chiral perturbation theory; lattice QCD; pion mass; kaon mass; decay constant; low-energy QCD; Physics and Astronomy;

   Sammanfattning : We use lattice QCD data to perform a fit of the pion and kaon mass and decay constant to next-to-next-to-leading order (NNLO) in three-flavor Chiral Perturbation Theory (ChPT). To improve our fits, we make use of finite volume corrections at both one- and two-loop order. This turns out to provide a small but noticeable improvement of our fits. LÄS MER

7. 5. Chiral Perturbation Theory for Neutron-Antineutron Oscillations

   Master-uppsats, Lunds universitet/Institutionen för astronomi och teoretisk fysik - Genomgår omorganisation

   Författare :Erik Kofoed; [2016]
   Nyckelord :Neutron-antineutron Oscillations; Baryon Number Violation; Chiral Perturbation Theory; Effective Field Theory; Spurions; Physics and Astronomy;

   Sammanfattning : This thesis treats neutron-antineutron oscillations in the framework of chiral perturbation theory. An effective Lagrangian, using mesons and nucleons as degrees of freedom, is constructed to capture the low-energy behavior of the effective six-quark operators, which is the set of higher dimensional operators that can induce neutron to antineutron transitions at the quark level. LÄS MER