About the fine-tuning price of LEP

Abstract

Following Chankowski, Ellis and Pokorski we quantify the amount of fine-tuning of input parameters of the Minimal Supersymmetric Standard Model that is needed to respect the lower limits on sparticle and Higgs masses imposed by negative searches so far, direct or indirect. By including the one loop radiative corrections to the effective potential, the amount of fine-tuning is reduced with respect to the results of CEP by a factor of 2--5, strongly increasing as tanβapproaches 1. A further reduction factor may come from a more appropriate, less restrictive, definition of the fine-tuning parameter itself.