  We report on a search for charged massive long-lived particles (CMLLPs),
based on 5.2 fb$^{-1}$ of data collected with the D0 detector at the Fermilab
Tevatron $p\bar{p}$ collider. CMLLPs are predicted in many theories of physics
beyond the standard model. We look for events in which one or more particles
are reconstructed as muons but have speed and ionization energy loss $dE/dx$
inconsistent with muons produced in beam collisions. We present 95% C.L. upper
limits on the production cross section for long-lived scalar taus, for
long-lived charginos in two SUSY scenarios, and for long-lived scalar top
quarks. We also present exclusion mass ranges for the chargino and scalar top
quark models.
