%0 Thesis
%A Fuchs, Elina
%T Interference effects in new physics processes at the LHC
%N DESY-THESIS-2015-037
%@ 1435-8085
%I Universität Hamburg
%V Dissertation
%C Hamburg
%M PUBDB-2015-03479
%M DESY-THESIS-2015-037
%B DESY-THESIS
%P 188
%D 2015
%Z Dissertation, Universität Hamburg, 2015
%X Interference effects between nearly mass-degenerate particles are ad-dressed in this thesis, comprising higher-order calculations, a model-independent method to calculate interference terms efficiently and aphenomenological application to current Higgs searches at the LHC.Predictions of cross sections and decay widths can be severelyaffected by interference terms between quasi-degenerate states arising inmodels beyond the Standard Model. We formulate a generalisation ofthe narrow-width approximation (NWA) which allows for a consistenttreatment of such effects by factorising the interference term into on-shellmatrix elements of the production and decay parts, optionally furtherapproximated as simple interference weight factors, incorporating one-loop and real corrections in a UV- and IR-finite way. We apply thegeneralised NWA to interfering MSSM Higgs bosons in the processχ 04 → χ 01 Φ → χ 01 τ + τ − , Φ = h, H and achieve an agreement of betterthan 1
%F PUB:(DE-HGF)3 ; PUB:(DE-HGF)11
%9 BookDissertation / PhD Thesis
%R 10.3204/DESY-THESIS-2015-037
%U https://bib-pubdb1.desy.de/record/224288