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 have measured the W -boson mass MW using data corresponding to 2.2 fb −1 of integrated luminosity collected in pp collisions at √ s = 1.96 TeV with the CDF II detector at the Fermilab Tevatron collider. Samples consisting of 470 126 W → eν candidates and 624 708 W → µν candidates yield the measurement MW = 80 387 ± 12stat ± 15syst = 80 387 ± 19 MeV/c 2 . This is the most precise measurement of the W -boson mass to date and significantly exceeds the precision of all previous measurements combined. PACS numbers: 13.38.Be, 14.70.Fm, 12.15.Ji, 13.85.Qk The mass of the W boson, M W , is an important parameter of the standard model (SM) of particle physics. Precise measurements of M W and of other electroweak observables significantly constrain the mass of the as-yet * Deceased † With visitors from

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.

We combine searches by the CDF and D0 Collaborations for the associated production of a Higgs boson with a W or Z boson and subsequent decay of the Higgs boson to a bottom-antibottom quark pair. The data, originating from Fermilab Tevatron pp collisions at √ s = 1.96 TeV, correspond to integrated luminosities of up to 9.7 fb −1 . The searches are conducted for a Higgs boson with mass in the range 100-150 GeV/c 2 . We observe an excess of events in the data compared with the background predictions, which is most significant in the mass range between 120 and 135 GeV/c 2 . The largest local significance is 3.3 standard deviations, corresponding to a global significance of 3.1 standard deviations. We interpret this as evidence for the presence of a new particle consistent with the standard model Higgs boson, which is produced in association with a weak vector boson and decays to a bottom-antibottom quark pair.

We report the observation of electroweak single top quark production in 3.2 fb −1 of pp collision data collected by the Collider Detector at Fermilab at √ s = 1.96 TeV. Candidate events in the W +jets topology with a leptonically decaying W boson are classified as signal-like by four parallel analyses based on likelihood functions, matrix elements, neural networks, and boosted decision trees. These results are combined using a super discriminant analysis based on genetically evolved neural networks in order to improve the sensitivity. This combined result is further combined with that of a search for a single top quark signal in an orthogonal sample of events with missing transverse energy plus jets and no charged lepton. We observe a signal consistent with the standard model prediction but inconsistent with the background-only model by 5.0 standard deviations, with a median expected sensitivity in excess of 5.9 standard deviations. We measure a production cross section of 2.3 +0.6 −0.5 (stat + sys) pb, extract the CKM matrix element value |V tb | = 0.91 +0.11 −0.11 (stat + sys) ± 0.07(theory), and set a lower limit |V tb | > 0.71 at the 95% confidence level, assuming mt = 175 GeV/c 2 .