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 a measurement of the single top quark production cross section in 2.2 fb −1 of pp collision data collected by the Collider Detector at Fermilab at √ s = 1.96 TeV. Candidate events are classified as signal-like by three parallel analyses which use likelihood, matrix element, and neural network discriminants. These results are combined in order to improve the sensitivity. We observe a signal consistent with the standard model prediction, but inconsistent with the backgroundonly model by 3.7 standard deviations with a median expected sensitivity of 4.9 standard deviations. We measure a cross section of 2.2 +0.7 −0.6 (stat + sys) pb, extract the CKM matrix element value |V tb | = 0.88 +0.13 −0.12 (stat + sys) ± 0.07(theory), and set the limit |V tb | > 0.66 at the 95% C.L.

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 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 present a search for new particles which produce narrow two-jet (dijet) resonances using protonantiproton collision data corresponding to an integrated luminosity of 1:13 fb À1 collected with the CDF II detector. The measured dijet mass spectrum is found to be consistent with next-to-leading-order perturbative QCD predictions, and no significant evidence of new particles is found. We set upper limits at the 95% confidence level on cross sections times the branching fraction for the production of new particles decaying into dijets with both jets having a rapidity magnitude jyj < 1. These limits are used to determine the mass exclusions for the excited quark, axigluon, flavor-universal coloron, E 6 diquark, coloroctet techni-, W 0 , and Z 0 .