2000/10/27 by P. Urban, Urban, P.
Physics and Astronomy · #FOS: Physical sciences #High Energy Physics - Phenomenology (hep-ph) #Particle Detector Development and Performance #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions #hep-ph
paper · pdf · doi:10.48550/arxiv.hep-ph/0010318
PhD thesis, 70 pages, 22 figures
openalex publication_date 2000/10/27 · arxiv created 2001/04/25 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Perturbative and nonperturbative QCD corrections to semileptonic B decay rates are calculated and given in analytical and numerical forms. We present the analytic expression for the double distribution in hadronic mass and electron energy in B to X(u) e nue decays through one loop order of QCD. We then study the leading twist corrections to that quantity within the formalism of HQET and employ it in a proposed method of measuring Vub with an accuracy of 10%. Our other point of interest is the polarisation of the tau lepton in B to X(c) tau nutau processes. Analytic formulae are given for the one-loop QCD correction to the longitudinal polarisation. The resulting moments of distributions are discussed, incorporating the HQET corrections found by Falk et al. The polarisation receives only a very small perturbative correction. It can be used in extracting the quark masses. Experimental considerations led us to the calculation of corrections to the polarisation of tau with respect to the momentum of the virtual W boson. Analytical results for the O(1/mb2) terms have been combined with numerically evaluated perturbative contributions to give the corrected polarisation.