Improved interpolating fields in the Schrödinger functional [Elektronische Ressource] / von Heiko Molke

Improved interpolating fields in theSchrodinger Functional¨D I S S E R T A T I O Nzur Erlangung des akademischen Gradesdoctor rerum naturalium(Dr. rer. nat.)im Fach Physikeingereicht an derMathematisch–Naturwissenschaftlichen Fakultat I¨Humboldt–Universitat zu Berlin¨vonHerrn Dipl.–Phys. Heiko Molkegeboren am 01.02.1976 in Frankfurt/OderPrasident der Humboldt-Universitat zu Berlin:¨ ¨Prof. Dr. Jurgen Mlynek¨Dekan der Mathematisch–Naturwissenschaftlichen Fakultat I:¨Prof. Dr. Michael LinscheidGutachter:1. Prof. Dr. U. Wolff2. Dr. R. Sommer3. Dr. H. Wittigeingereicht am: 16.01.2004Tag der mundlic¨ hen Prufung:¨ 26.04.2004AbstractThe general aim of this thesis is to probe several methods to extract low-energy quantities (masses, decay constants, ...) more reliably in lattice gau-ge theory. We will investigate how to suppress contributions to correlationfunctions from the first excited meson state. We will show how to constructso-called improved meson interpolating fields, as they have only small con-tributions from the first excited meson state, from a basis of interpolatingfields at the Schrodinger functional boundaries.¨The variational principle is applied to correlation matrices that are builtup from boundary-to-boundary correlation functions. It will deliver informa-tion about the lowest-lying meson states in the considered channel.