Search for New Particles Leading to Z+jets Final States in pp Collisions at √s=1.96 TeV

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We present the results of a search for new particles that lead to a boson plus jets in pp collisions at √s=1.96 TeV using the Collider Detector at Fermilab (CDF II). A data sample with a luminosity of 1.06 collected using boson decays to ee and μμ is used. We describe a completely data-based method to predict the dominant background from standard-model +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 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' → b) = 100% and using a leading-order calculation of the b' cross section, b' quark masses below 268 /c² are excluded at 95% confidence level.