The order $G sb{F}m sbsp{t}{2}$ electro-weak corrections to the decay $t to bW sp+$ are calculated, arising essentially from virtual radiation of the Higgs boson. For large $m sb{t}$ these represent the dominant effect serving to shift the top lifetime from its tree level value. In practice, for $m sb{t}$ $<$ 240 $GeV$ these corrections are typically 0.1%. A comparison with recent calculations of the complete electro-weak and strong effects is made. / Several contributions to the branching ratio for the inclusive decay $ Upsilon to J/ psi X$ are calculated using perturbative Q.C.D. to lowest order in the relative quark momentum and the strong coupling $ alpha sb{s}$. In addition to the direct transition, decay to J/$ psi$ through the states $ psi sp prime$ and $ chi sb1$ is also considered. The following results are obtained: $Br( Upsilon to psi sp prime X$) = (0.26 $ pm$ 0.13) $ times$ 10$ sp{-3}$, $Br( Upsilon to chi sb1 X$) $ le$ 0.17 $ times$ 10$ sp{-3}$, and $Br( Upsilon to J/ psi X$) = (0.44 $ pm$ 0.15) $ times$ 10$ sp{-3}$. The latter may just be consistent with the experimental result (1.1 $ pm$ 0.4 $ pm$ 0.2) $ times$ 10$ sp{-3}$ where the first error is statistical and the second systematic.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.70312 |
| Date | January 1991 |
| Creators | Irwin, Blake A. |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Doctor of Philosophy (Department of Physics.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 001271582, proquestno: AAINN74754, Theses scanned by UMI/ProQuest. |
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