We present a new measurement of the inclusive forward-backward tt production asymmetry and its rapidity and mass dependence. The measurements are performed with data corresponding to an integrated luminosity of 5.3 fb −1 of pp collisions at √ s = 1.96 TeV, recorded with the CDF II Detector at the Fermilab Tevatron. Significant inclusive asymmetries are observed in both the laboratory frame and the tt rest frame, and in both cases are found to be consistent with CP conservation under interchange of t andt. In the tt rest frame, the asymmetry is observed to increase with the tt rapidity difference, ∆y, and with the invariant mass M tt of the tt system. Fully corrected parton-level asymmetries are derived in two regions of each variable, and the asymmetry is found to be most significant at large ∆y and M tt . For M tt ≥ 450 GeV/c 2 , the parton-level asymmetry in the tt rest frame is A tt = 0.475 ± 0.114 compared to a next-to-leading order QCD prediction of 0.088 ± 0.013.

We report on a search for new particles in the diphoton channel using a data sample of pp collisions at √ s = 1.96 TeV collected by the CDF II detector at the Fermilab Tevatron, with an integrated luminosity of 5.4 fb −1 . The diphoton invariant mass spectrum of the data agrees well with the standard model expectation. We set upper limits on the production cross section times branching ratio for the Randall-Sundrum graviton, as a function of diphoton mass. We subsequently derive lower limits on the graviton mass of 459 GeV/c 2 and 963 GeV/c 2 , at the 95% confidence level, for coupling parameters (k/M P l ) of 0.01 and 0.1 respectively.

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We report a study of the invariant mass distribution of jet pairs produced in association with a W boson using data collected with the CDF detector which correspond to an integrated luminosity of 4.3 fb −1 . The observed distribution has an excess in the 120-160 GeV/c 2 mass range which is not described by current theoretical predictions within the statistical and systematic uncertainties. In this letter we report studies of the properties of this excess.