Abstract
In this thesis the B{sup 0}- anti B{sup 0} mixing parameter {chi} is measured. The data have been collected using the DELPHI detector at the electron-positron accelerator LEP at CERN in Geneva. At the LEP energy of about 91 GeV the Z{sup 0} particle is produced. About 15 percent of the time the Z{sup 0} decays into a b anti b-pair, which makes LEP an ideal environment to study the properties of the heavy b quark. In this thesis, the signal for the measurement of {chi} consists of events in which there are two leptons in the final state. If both leptons directly originate from a b quark decay (b{yields}l), then their charge reflects the one of the b quark. Events with leptons of the same sign indicate the presence of B{sup 0}- anti B{sup 0} mixing. The neural network variable achieves a better separation between the signal and the background than the transverse moemntum. Using data recorded by DELPHI in 1992, one obtains for the mixing parameter {chi}=8.6%{+-}2.3%(stat){+-}0.6%(sys). (orig./WL).
Citation Formats
Los, M E.
A measurement of the B{sup 0} anti B{sup 0} mixing parameter at LEP using a neural network.
Netherlands: N. p.,
1995.
Web.
Los, M E.
A measurement of the B{sup 0} anti B{sup 0} mixing parameter at LEP using a neural network.
Netherlands.
Los, M E.
1995.
"A measurement of the B{sup 0} anti B{sup 0} mixing parameter at LEP using a neural network."
Netherlands.
@misc{etde_406898,
title = {A measurement of the B{sup 0} anti B{sup 0} mixing parameter at LEP using a neural network}
author = {Los, M E}
abstractNote = {In this thesis the B{sup 0}- anti B{sup 0} mixing parameter {chi} is measured. The data have been collected using the DELPHI detector at the electron-positron accelerator LEP at CERN in Geneva. At the LEP energy of about 91 GeV the Z{sup 0} particle is produced. About 15 percent of the time the Z{sup 0} decays into a b anti b-pair, which makes LEP an ideal environment to study the properties of the heavy b quark. In this thesis, the signal for the measurement of {chi} consists of events in which there are two leptons in the final state. If both leptons directly originate from a b quark decay (b{yields}l), then their charge reflects the one of the b quark. Events with leptons of the same sign indicate the presence of B{sup 0}- anti B{sup 0} mixing. The neural network variable achieves a better separation between the signal and the background than the transverse moemntum. Using data recorded by DELPHI in 1992, one obtains for the mixing parameter {chi}=8.6%{+-}2.3%(stat){+-}0.6%(sys). (orig./WL).}
place = {Netherlands}
year = {1995}
month = {Nov}
}
title = {A measurement of the B{sup 0} anti B{sup 0} mixing parameter at LEP using a neural network}
author = {Los, M E}
abstractNote = {In this thesis the B{sup 0}- anti B{sup 0} mixing parameter {chi} is measured. The data have been collected using the DELPHI detector at the electron-positron accelerator LEP at CERN in Geneva. At the LEP energy of about 91 GeV the Z{sup 0} particle is produced. About 15 percent of the time the Z{sup 0} decays into a b anti b-pair, which makes LEP an ideal environment to study the properties of the heavy b quark. In this thesis, the signal for the measurement of {chi} consists of events in which there are two leptons in the final state. If both leptons directly originate from a b quark decay (b{yields}l), then their charge reflects the one of the b quark. Events with leptons of the same sign indicate the presence of B{sup 0}- anti B{sup 0} mixing. The neural network variable achieves a better separation between the signal and the background than the transverse moemntum. Using data recorded by DELPHI in 1992, one obtains for the mixing parameter {chi}=8.6%{+-}2.3%(stat){+-}0.6%(sys). (orig./WL).}
place = {Netherlands}
year = {1995}
month = {Nov}
}