Topological search for the production of neutralinos and scalar particles

doi:10.1016/0370-2693(96)00502-3

Physics Letters B

Volume 377, Issue 4, 13 June 1996, Pages 273-288

https://doi.org/10.1016/0370-2693(96)00502-3 Get rights and content

Abstract

A search for scalar particles and neutralinos such as those predicted by supersymmetric models has been performed using a data sample of 4.4 million hadronic Z⁰ decays recorded by the OPAL detector at the e⁺e⁻ collider LEP. The production of such particles typically leads to event topologies consisting of an acoplanar pair of jets, or of a mono-jet, accompanied by sizeable missing energy owing to neutrinos and other undetectable neutral particles. Limits are obtained, at the 95% confidence level, on the masses and production rates of scalar particles produced in association with the Z⁰. Limits are also placed on neutralino production, for which an additional possible signature is also studied, events containing a single observed photon. Within the Minimal Supersymmetric Standard Model, the mass of the lightest neutralino is found to be larger than 12.5 GeV/c² at 95% C.L., provided that tan β is larger than 1.5.

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¹: And at TRIUMF, Vancouver, Canada V6T 2A3

²: And Royal Society University Research Fellow

³: And Institute of Nuclear Research, Debrecen, Hungary

⁴: And Depart of Experimental Physics, Lajos Kossuth University, Debrecen, Hungary

⁵: And Ludwig-Maximilians-Universität, München, Germany

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Topological search for the production of neutralinos and scalar particles

Abstract

Z. Physics at LEP1, CERN 89-08

Nucl. Phys. B

Phys. Lett. B

Phys. Lett. B

Nucl. Phys. B

Phys. Lett. B

Phys. Rev. Lett.

Phys. Lett. B

Phys. Rev. D

Nucl. Phys. B

Phys. Lett. B

Phys. Lett. B

Phys. Lett. B

Phys. Rev. D

Nucl. Phys. B

Phys. Rev. Lett.

Nucl. Instrum. Methods A

Phys. Lett. B

Z. Phys. C

KEK Report 91-11

Nucl. Phys. B

Z. Phys. C

Z. Phys. C

Z. Phys. C

Z. Phys. C

Phys. Rev. D

Phys. Rep.

Phys. Lett. B

Phys. Rev. D

Phys. Rev. Lett.

Elementary Particle Theory

Phys. Lett.

Phys. Rev. Lett.

Phys. Rev. Lett.