Search for highly ionizing particles in e+e- collisions at s=29 GeV

The results of the analysis of data taken in the continuation of a previously reported search for highly ionizing particles at PEP are presented. Assemblies consisting of Lexan and CR-39 plastic track detectors were exposed in two runs to integrated luminosities of 30×10³⁶ cm^-2 and 150×10³⁶ cm^-2. The search was sensitive to particles with magnetic charge 20e<=g<=200e or electric charge 3<=Z<=180. A combined (95% C.L.) upper limit on the production cross section of σ<3.2×10^-38 cm² is obtained, improving our previous limits by more than an order of magnitude.