Limits on the production of massive stable charged particles

We present improved limits on the production of massive stable charged particles in $\overline{p}p$ collisions using the Collider Detector at Fermilab based on an integrated luminosity of 3.54 ${\mathrm{pb}}^{-1\mathrm{}}$. Both unit and fractionally charged particles are considered. Cross-section upper limits are determined for masses from 50 to 500 GeV/${\mathit{c}}^2$. Theoretical cross sections are used to set bounds on the mass of fermionic color triplets, sextets, octets, and decuplets as well as scalar triplets.