|   | 
Details
   web
Records
Author Hansen, M.T.; Romero-Lopez, F.; Sharpe, S.R.
Title Decay amplitudes to three hadrons from finite-volume matrix elements Type Journal Article
Year 2021 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 04 Issue 4 Pages 113 - 44pp
Keywords Lattice QCD; Kaon Physics
Abstract We derive relations between finite-volume matrix elements and infinite-volume decay amplitudes, for processes with three spinless, degenerate and either identical or non-identical particles in the final state. This generalizes the Lellouch-Luscher relation for two-particle decays and provides a strategy for extracting three-hadron decay amplitudes using lattice QCD. Unlike for two particles, even in the simplest approximation, one must solve integral equations to obtain the physical decay amplitude, a consequence of the nontrivial finite-state interactions. We first derive the result in a simplified theory with three identical particles, and then present the generalizations needed to study phenomenologically relevant three-pion decays. The specific processes we discuss are the CP-violating K -> 3 pi weak decay, the isospin-breaking eta -> 3 pi QCD transition, and the electromagnetic gamma (*) -> 3 pi amplitudes that enter the calculation of the hadronic vacuum polarization contribution to muonic g – 2.
Address [Hansen, Maxwell T.] Univ Edinburgh, Sch Phys & Astron, Higgs Ctr Theoret Phys, Edinburgh EH9 3FD, Midlothian, Scotland, Email: maxwell.hansen@ed.ac.uk;
Corporate Author Thesis
Publisher (up) Springer Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1029-8479 ISBN Medium
Area Expedition Conference
Notes WOS:000640574400001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4789
Permanent link to this record
 

 
Author Pich, A.; Rodriguez-Sanchez, A.
Title SU(3) analysis of four-quark operators: K -> pi pi and vacuum matrix elements Type Journal Article
Year 2021 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 06 Issue 6 Pages 005 - 43pp
Keywords Chiral Lagrangians; CP violation; Effective Field Theories; Kaon Physics
Abstract Hadronic matrix elements of local four-quark operators play a central role in non-leptonic kaon decays, while vacuum matrix elements involving the same kind of operators appear in inclusive dispersion relations, such as those relevant in tau -decay analyses. Using an SU(3)(L) circle times SU(3)(R) decomposition of the operators, we derive generic relations between these matrix elements, extending well-known results that link observables in the two different sectors. Two relevant phenomenological applications are presented. First, we determine the electroweak-penguin contribution to the kaon CP-violating ratio epsilon '/epsilon, using the measured hadronic spectral functions in tau decay. Second, we fit our SU(3) dynamical parameters to the most recent lattice data on K -> pi pi matrix elements. The comparison of this numerical fit with results from previous analytical approaches provides an interesting anatomy of the Delta I = 1/2 enhancement, confirming old suggestions about its underlying dynamical origin.
Address [Pich, A.] Univ Valencia, CSIC, IFIC, Dept Fis Teor, Edifici Inst Paterna,Apt Correus 22085, E-46071 Valencia, Spain, Email: Antonio.Pich@ific.uv.es;
Corporate Author Thesis
Publisher (up) Springer Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1029-8479 ISBN Medium
Area Expedition Conference
Notes WOS:000762295200001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5148
Permanent link to this record