Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - Z production cross-sections and lepton pair forward-backward asymmetries
AU - Buskulic, D.
AU - Finch, Alexander
AU - ALEPH Collaboration
PY - 1994
Y1 - 1994
N2 - Precise values of theZ resonance cross sections and lepton pair forward-backward asymmetries are measured from a sample of 1.3 millionZ decays into hadrons and charged leptons taken with the ALEPH detector at LEP. A silicon-tungsten luminosity calorimeter was installed in ALEPH in 1992, permitting the determination of the absolute luminosity to a systematic precision of 0.15% (experimental) and 0.25% (theoretical). This is combined with a better understanding of the hadronic event selection and an improved tau pair selection. Including the ALEPH results of the past three years one obtains σh0 =(41.60±0.16) nb, andRl=20.69±0.09. The corresponding number of light neutrino species isNv =2.983±0.034. The lepton pair forward-backward asymmetry is used to derive the ratio of vector to axial-vector couplings of leptons:gV2(MZ2)/gA2(MZ2)=0.0058 ±0.0011. An application of these results to constrain one model with extraZ bosons is presented.
AB - Precise values of theZ resonance cross sections and lepton pair forward-backward asymmetries are measured from a sample of 1.3 millionZ decays into hadrons and charged leptons taken with the ALEPH detector at LEP. A silicon-tungsten luminosity calorimeter was installed in ALEPH in 1992, permitting the determination of the absolute luminosity to a systematic precision of 0.15% (experimental) and 0.25% (theoretical). This is combined with a better understanding of the hadronic event selection and an improved tau pair selection. Including the ALEPH results of the past three years one obtains σh0 =(41.60±0.16) nb, andRl=20.69±0.09. The corresponding number of light neutrino species isNv =2.983±0.034. The lepton pair forward-backward asymmetry is used to derive the ratio of vector to axial-vector couplings of leptons:gV2(MZ2)/gA2(MZ2)=0.0058 ±0.0011. An application of these results to constrain one model with extraZ bosons is presented.
U2 - 10.1007/BF01574159
DO - 10.1007/BF01574159
M3 - Journal article
VL - 62
SP - 539
EP - 550
JO - Zeitschrift für Physik C Particles and Fields
JF - Zeitschrift für Physik C Particles and Fields
SN - 0170-9739
IS - 4
ER -