Abstract
This work has been achieved within the ALEPH experiment installed on the electron-positron collider LEP at CERN, in order to determine the number of light neutrino species, a free parameter of the Standard model. To perform the measurements, a method based on single photon final states is chosen, where neutrino-antineutrino pair is undetected. The cross-section of such a process is almost proportional to the number of neutrino species. Such events are selected according to criteria which reject background not coming from electron-positron interactions. Other background contributions have been estimated using detailed simulations. The signal-background separation is improved by a maximum of likelihood method. From the signal cross-section, a number of neutrino species of 2.65 {+-} 2*(0.20) is derived.
Citation Formats
El Fellous, R.
Single photon cross-section measurements with the ALEPH detector: determination of the number of neutrinos; Mesure de la section efficace de photons uniques avec le detecteur Aleph: determination du nombre de neutrinos.
France: N. p.,
1992.
Web.
El Fellous, R.
Single photon cross-section measurements with the ALEPH detector: determination of the number of neutrinos; Mesure de la section efficace de photons uniques avec le detecteur Aleph: determination du nombre de neutrinos.
France.
El Fellous, R.
1992.
"Single photon cross-section measurements with the ALEPH detector: determination of the number of neutrinos; Mesure de la section efficace de photons uniques avec le detecteur Aleph: determination du nombre de neutrinos."
France.
@misc{etde_10127389,
title = {Single photon cross-section measurements with the ALEPH detector: determination of the number of neutrinos; Mesure de la section efficace de photons uniques avec le detecteur Aleph: determination du nombre de neutrinos}
author = {El Fellous, R}
abstractNote = {This work has been achieved within the ALEPH experiment installed on the electron-positron collider LEP at CERN, in order to determine the number of light neutrino species, a free parameter of the Standard model. To perform the measurements, a method based on single photon final states is chosen, where neutrino-antineutrino pair is undetected. The cross-section of such a process is almost proportional to the number of neutrino species. Such events are selected according to criteria which reject background not coming from electron-positron interactions. Other background contributions have been estimated using detailed simulations. The signal-background separation is improved by a maximum of likelihood method. From the signal cross-section, a number of neutrino species of 2.65 {+-} 2*(0.20) is derived.}
place = {France}
year = {1992}
month = {Oct}
}
title = {Single photon cross-section measurements with the ALEPH detector: determination of the number of neutrinos; Mesure de la section efficace de photons uniques avec le detecteur Aleph: determination du nombre de neutrinos}
author = {El Fellous, R}
abstractNote = {This work has been achieved within the ALEPH experiment installed on the electron-positron collider LEP at CERN, in order to determine the number of light neutrino species, a free parameter of the Standard model. To perform the measurements, a method based on single photon final states is chosen, where neutrino-antineutrino pair is undetected. The cross-section of such a process is almost proportional to the number of neutrino species. Such events are selected according to criteria which reject background not coming from electron-positron interactions. Other background contributions have been estimated using detailed simulations. The signal-background separation is improved by a maximum of likelihood method. From the signal cross-section, a number of neutrino species of 2.65 {+-} 2*(0.20) is derived.}
place = {France}
year = {1992}
month = {Oct}
}