Search for narrow high-mass resonances in radiative decays of the Z<sup>0</sup>

We search for new resonances, Y, with mass M<sub>Y</sub>, in the range from 30 to 89 GeV, produced via the reaction e+e− → Z<sup>0</sup> →γY, where Y subsequently decays into e+e−, μ+μ− or hadrons. We use 5.5.pb<sup>−1</sup> of data collected in the energy range 8...

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Detalles Bibliográficos
Autores principales: Dova, María Teresa, L3 Collaboration
Formato: Articulo
Lenguaje:Inglés
Publicado: 1991
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Acceso en línea:http://sedici.unlp.edu.ar/handle/10915/81642
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Sumario:We search for new resonances, Y, with mass M<sub>Y</sub>, in the range from 30 to 89 GeV, produced via the reaction e+e− → Z<sup>0</sup> →γY, where Y subsequently decays into e+e−, μ+μ− or hadrons. We use 5.5.pb<sup>−1</sup> of data collected in the energy range 88.2 ≤ √s ≤ 94.2 GeV, near the Z<sup>0</sup> peak. We obtain the following upper limits, at the 95% confidence level, on the product of the branching ratios: BR(Z<sup>0</sup> → γY) × BR(Y → e+e−) < 2.8 × 10<sup>−4</sup> for 30 < M<sub>Y</sub> < 89, BR(Z<sup>0</sup> →γY × BR(Y → μ+μ−) < 2.3 × 10<sup>−4</sup> for 30 < M<sub>Y</sub> < 89, BR(Z<sup>0</sup>→ γY) × BR(Y → hadrons) < 4.7 × 10<sup>−4</sup> for 30 < M<sub>Y</sub> < 86. These limits are valid for resonances with widths smaller than our mass resolution.