Precision determination of the electroweak mixing angle and test of neutral current universality from the tau polarization measurements at OPAL
| dc.contributor.author | Graham, Kevin | |
| dc.contributor.supervisor | Roney, J. Michael | |
| dc.date.accessioned | 2018-08-16T23:07:27Z | |
| dc.date.available | 2018-08-16T23:07:27Z | |
| dc.date.copyright | 2001 | en_US |
| dc.date.issued | 2018-08-16 | |
| dc.degree.department | Department of Physics and Astronomy | |
| dc.degree.level | Doctor of Philosophy Ph.D. | en_US |
| dc.description.abstract | Measurements of the Ƭ lepton polarization and forward-backward polarization asymmetry near the Z° resonance using the OPAL detector are described. The measurements are based on analyses of [special characters omitted] decays from a sample of 144, 810 [special characters omitted] candidates corresponding to an integrated luminosity of 151 pb-1. Assuming that the Ƭ lepton decays according to V-A theory, the average Ƭ polarization near [special characters omitted] is measured to be [special characters omitted] = (-14.10 ± 0.73 ± 0.55)% and the Ƭ polarization forward-backward asymmetry to be [special characters omitted] = (-10.55 ± 0.76 ± 0.25)%, where the first error is statistical and the second systematic. Taking into account the small effects of the photon propagator, photon-Z° interference and photonic radiative corrections, these results can be expressed in terms of the lepton neutral current asymmetry parameters: AƬ = 0.1466 ± 0.0076 ± 0.0057, Ae = 0.1464 ± 0.0108 ± 0.0036. These measurements are consistent with the hypothesis of lepton universality and combine to give [special characters omitted] = 0.1455 ± 0.0073. Within the context of the standard model this combined result corresponds to sin [special characters omitted] = 0.23172 ± 0.00092. Combining these results with those from the other OPAL neutral current measurements yields a value of sin [special characters omitted] = 0.23211 ± 0.00068. | en_US |
| dc.description.scholarlevel | Graduate | en_US |
| dc.identifier.uri | http://hdl.handle.net/1828/9928 | |
| dc.language | English | eng |
| dc.language.iso | en | en_US |
| dc.rights | Available to the World Wide Web | en_US |
| dc.subject | Heavy particles (Nuclear physics) | en_US |
| dc.subject | Kaons | en_US |
| dc.subject | Radioactive decay | en_US |
| dc.title | Precision determination of the electroweak mixing angle and test of neutral current universality from the tau polarization measurements at OPAL | en_US |
| dc.type | Thesis | en_US |