  A search is performed for heavy metastable particles that decay into jet
pairs with a macroscopic lifetime (ctau ~ 1 cm) in ppbar collisions at sqrt{s}
= 1.96 TeV using data from the CDF II detector at Fermilab corresponding to an
integrated luminosity of 3.2 fb^-1. To estimate the standard model background a
data-driven approach is used. Probability-density functions are constructed to
model secondary vertices from known processes. No statistically significant
excess is observed above the background. Limits on the production cross section
in a hidden valley benchmark phenomenology are set for various Higgs boson
masses as well as metastable particle masses and lifetimes.
