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arXiv · hep-ex/0210043

Search for Nearly Mass-Degenerate Charginos and Neutralinos at LEP

The OPAL collaboration
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Abstract

A search was performed for charginos with masses close to the mass of the lightest neutralino in e+e- collisions at centre-of-mass energies of 189-209 GeV recorded by the OPAL detector at LEP. Events were selected if they had an observed high-energy photon from initial state radiation, reducing the dominant background from two-photon scattering to a negligible level. No significant excess over Standard Model expectations has been observed in the analysed data set corresponding to an integrated luminosity of 570pb-1. Upper limits were derived on the chargino pair-productin cross-section, and lower limits on the chargino mass were derived in the context of the Minimal Supersymmetric Extension of the Standard Model for the gravity and anomaly mediated Supersymmetry breaking scenarios.

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The OPAL collaboration. 2002-10-17. Search for Nearly Mass-Degenerate Charginos and Neutralinos at LEP. https://doi.org/10.1140/epjc%2Fs2003-01237-x

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