Naturalness Implications of LEP Results

Abstract

We analyse the fine-tuning constraints arising from absence of superpartners at LEP, without strong universality assumptions. We show that such constraints do not imply that charginos or neutralinos should have been seen at LEP, contrary to the usual arguments. They do however imply relatively light gluinos $(m_{\tilde g} \lsim 350 GeV)$ and/or a relation between the soft-breaking SU(3) gaugino mass and Higgs soft mass $m_{H_U}$. The LEP limit on the Higgs mass is significant, especially at low $\tan \beta$, and we investigate to what extent this provides evidence for both a lighter gluino and correlations between soft masses.