Search for New Particles at LEP

TL;DR

This paper reviews LEP's 1999 search results for Higgs and supersymmetric particles, setting new mass limits and constraints, with no signals observed, enhancing understanding of particle physics beyond the Standard Model.

Contribution

It provides the most recent limits on Higgs and supersymmetric particles from LEP, including comprehensive parameter scans and combined data analysis.

Findings

No signal observed for Higgs or supersymmetric particles.

Lower mass limit of 102.6 GeV for the Standard Model Higgs.

Constraints on charged Higgs and supersymmetric partners.

Abstract

The latest preliminary results of the searches for Higgs bosons and Supersymmetric particles at LEP are reviewed. The results include the data-taking in 1999 up to center-of-mass energies of 196 GeV. The combination of the results from the four LEP experiments leads to a significant increase of the detection sensitivity. No indication of a signal has been observed. In the Standard Model (SM) a lower limit of 102.6 GeV on the mass of the Higgs boson is set at 95% CL. In extended models, stringent limits are also set on the HZZ coupling. Interpretations in the Minimal extension of the Supersymmetric Standard Model (MSSM) are given and the importance of general MSSM parameter scans is emphasized. In general scans, the limit on the mass of the lightest scalar Higgs boson is about 7 GeV lower in comparison with benchmark results. The data also constrains charged Higgs bosons of a general two-doublet model and Supersymmetric partners of the SM particles.