Scattering amplitudes with the multi-loop numerical unitarity method

Abstract: In this thesis, we develop and apply the D-dimensional numerical unitarity method for the computation of multi-loop scattering amplitudes, which are the key building blocks for precise theoretical predictions for the ongoing physics program of the Large Hadron Collider experiment at CERN. We formulate a framework for consistently implementing dimensional regularization in numerical approaches, which in particular can be applied for efficient numerical evaluations of dimensionally-regularized helicity amplitudes with external fermions. We present the next-to-leading order QCD predictions for the production of W boson in association with a pair of bottom quarks and light jets at the Large Hadron Collider, which is an irreducible background to the the studies of decays of the Higgs boson to a pair of bottom quarks. We include all the effects of the non-vanishing bottom-quark mass. To obtain the one-loop matrix elements required for the process, we implement an extension of the numerical unitarity method to massive particles in the loop. We present the first benchmark values and analytic form of all two-loop five-parton helicity amplitudes in QCD in the leading-color approximation. The analytic expressions are reconstructed from exact numerical evaluations with the numerical unitarity method. Our results provide all two-loop amplitudes required for the calculation of next-to-next-to-leading order QCD corrections to the production of three jets at hadron colliders in the leading-color approximation

Object Details

• Location: Deutsche Nationalbibliothek Frankfurt am Main
• Extent: Online-Ressource
• Language: Englisch
• Notes: Universität Freiburg, Dissertation, 2019

Classification and Topics

• Keyword: Quantenchromodynamik

Contributors, Places and Time

• Event: Veröffentlichung
• (where): Freiburg
• (who): Universität
• (when): 2019
• Creator: Sotnikov, Vasily
• Contributor: Ita, Harald ; Albert-Ludwigs-Universität Freiburg. Fakultät für Mathematik und Physik

Further information

• DOI: 10.6094/UNIFR/151540
• URN: urn:nbn:de:bsz:25-freidok-1515406
• Rights: Der Zugriff auf das Objekt ist unbeschränkt möglich.
• Last update: 25.03.2025, 1:57 PM CET