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.

The COMPASS Collaboration at CERN has measured the transverse spin azimuthal asymmetry of\ud charged hadrons produced in semi-inclusive deep inelastic scattering using a 160 GeV μ+ beam and a\ud transversely polarised NH3 target. The Sivers asymmetry of the proton has been extracted in the Bjorken\ud x range 0.003 < x < 0.7. The new measurements have small statistical and systematic uncertainties of\ud a few percent and confirm with considerably better accuracy the previous COMPASS measurement. The\ud Sivers asymmetry is found to be compatible with zero for negative hadrons and positive for positive\ud hadrons, a clear indication of a spin–orbit coupling of quarks in a transversely polarised proton. As\ud compared to measurements at lower energy, a smaller Sivers asymmetry for positive hadrons is found\ud in the region x > 0.03. The asymmetry is different from zero and positive also in the low x region,\ud where sea-quarks dominate. The kinematic dependence of the asymmetry has also been investigated and\ud results are given for various intervals of hadron and virtual photon fractional energy. In contrast to the\ud case of the Collins asymmetry, the results on the Sivers asymmetry suggest a strong dependence on the\ud four-momentum transfer to the nucleon, in agreement with the most recent calculations

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