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Determination of the effective number of light strongly interacting fermions frome + e − data

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Zeitschrift für Physik C Particles and Fields

Abstract

Both the topology of hadronic final states ine + e − collisions and the evolution of event shape distributions with center of mass energy depend on the total numberN of light fermion species which couple to gluons. From an analysis ofe + e − data between\(\sqrt s = 14\) GeV and\(\sqrt s = 91\) GeV I determineN=6.3±1.1. This result is compatible with both the Standard Model expectation of 5 and with the existence of a light gluino, in which caseN would be about 8.

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  1. PPE Division, CERN, CH-1211, Geneva 23, Switzerland

    Thomas Hebbeker

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  1. Thomas Hebbeker
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Hebbeker, T. Determination of the effective number of light strongly interacting fermions frome + e − data. Z. Phys. C - Particles and Fields 60, 63–69 (1993). https://doi.org/10.1007/BF01650431

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  • DOI: https://doi.org/10.1007/BF01650431

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