Neutral-current four-fermion production in e<sup>+</sup>e<sup>−</sup> interactions at LEP
Neutral-current four-fermion production, e<sup>+</sup>e<sup>-</sup> → f ̄f f' ̄ f', is studied in 0.7 fb<sup>−1</sup> of data collected with the L3 detector at LEP at centre-of-mass energies √s = 183–209 GeV. Four final states are considered: q ̄qν ̄ν, q...
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| Autores principales: | , |
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| Formato: | Articulo |
| Lenguaje: | Inglés |
| Publicado: |
2005
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| Materias: | |
| Acceso en línea: | http://sedici.unlp.edu.ar/handle/10915/79452 |
| Aporte de: |
| Sumario: | Neutral-current four-fermion production, e<sup>+</sup>e<sup>-</sup> → f ̄f f' ̄ f', is studied in 0.7 fb<sup>−1</sup> of data collected with the L3 detector at LEP at centre-of-mass energies √s = 183–209 GeV. Four final states are considered: q ̄qν ̄ν, q ̄qℓ<sup>+</sup>ℓ<sup>-</sup>, ℓ<sup>+</sup>ℓ<sup>-</sup>ℓ'<sup>+</sup>ℓ'<sup>-</sup> and ℓ<sup>+</sup>ℓ<sup>-</sup>ν ̄ν, where ℓ denotes either an electron or a muon. Their cross sections are measured and found to agree with the Standard Model predictions. In addition, the e<sup>+</sup>e<sup>-</sup> → Zγ <sup>∗</sup> → f ̄f f' ̄ f' process is studied and its total cross section at the average centre- of-mass energy (√s) = 196.6 GeV is found to be 0.29 ± 0.05 ± 0.03 pb, where the first uncertainty is statistical and the second systematic, in agreement with the Standard Model prediction of 0.22 pb. Finally, the mass spectra of the qq ̄ℓ<sup>+</sup>ℓ<sup>-</sup> final states are analysed to search for the possible production of a new neutral heavy particle, for which no evidence is found. |
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