Search for New Particles Leading to Z+jets Final States in $p\bar{p}$ Collisions at $\sqrt{s}=1.96$ TeV

We present the results of a search for new particles that lead to a \Z boson plus jets in $p\bar{p}$ collisions at $\sqrt{s}=1.96$ TeV using the Collider Detector at Fermilab (CDF II). A data sample with a luminosity of 1.06 \ifb
collected using \Z boson decays to $ee$ and $\mu \mu$ is used. We describe a completely data-based method to predict the dominant background from standard-model \Z+jet events. This method can be similarly applied to other analyses requiring background predictions in multi-jet environments, as shown when validating the method by predicting the background from $W$+jets in \ttbar production. No significant excess above the background prediction is observed, and a limit is set using a fourth generation quark model to quantify the acceptance. Assuming $BR(b^{\mathrm{\prime }}\to b\mathbb{Z})=100$ and using a leading-order calculation of the $b^{\mathrm{\prime }}$ cross section, $b^{\mathrm{\prime }}$ quark masses below 268 $\text{gev}\mathrm{/}{c}^2$ are excluded at 95% confidence level.