2019/03/22 by Sebastian Steinbeißer, Steinbeißer, Sebastian
Physics and Astronomy · #FOS: Physical sciences #High Energy Physics - Phenomenology (hep-ph) #High-Energy Particle Collisions Research #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions #hep-ph
paper · pdf · doi:10.48550/arxiv.1903.10352
Master thesis, Technical University of Munich (2017-02-21), Supervisors: Antonio Vairo and Nora Brambilla, 137 pages, 18 figures, 9 tables. arXiv admin note: text overlap with arXiv:1111.0165, arXiv:hep-ph/0101305, arXiv:hep-ph/0108084, arXiv:hep-ph/9806303 by other authors
openalex created_date 2018/12/22 · arxiv created 2019/03/22 · openalex publication_date 2019/03/22 · arxiv updated 2019/03/26 · openalex updated_date 2026/07/28
In this work we use the low-energy EFT called potential non-relativistic QCD (pNRQCD) to calculate the partial decay width of different bb-states undergoing an electric dipole transition at next-to-next-to leading order (NNLO). Explicitly, the χb J, for J=0,1,2, and the hb are investigated by computing the processes χb J → Υ+ γ and hb → ηb + γ. Relativistic corrections of relative order v2 to the leading electric dipole operator are included. The analysis separates those contributions that account for the electromagnetic interaction terms in the pNRQCD Lagrangian, which are v2 suppressed, and those that account for quarkonium state corrections of relative order v and v2. Within the last ones, corrections come from higher order potentials ((1)/(m) and (1)/(m2) terms), and from higher order Fock states which account for the coupling of the quark-antiquark state to other low-energy degrees of freedom and thus demand non-perturbative input. Finally, the experimentally known branching fractions are used to predict the total decay with of the respective initial states.