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I report some recent results on direct CP violation measurements in hadronic decays collected by the upgraded Collider Detector (CDF II) at the Fermilab Tevatron: CP-violating asymmetries in the two-body non-leptonic charmless decays of $b$-hadrons, the first reconstruction in hadron collisions of the suppressed decays $B^- to D(to K^+pi^-)K^-$ and $B^- to D(to K^+pi^-)pi^-$, and the measurement of TP asymmetries in the $B^{0}_{s} to phi phi$ decays.
Charm physics has played all along a central role in particle physics, however the level of attention on it has tremendously increased in the last years because of the observation of fast $D^0-bar{D}^0$ flavour oscillations and because of very recent observed hints of CP violation. While in the past these would have been unambiguously interpreted as signs of New Physics, the revisitation of theoretical expectations, prompted by the latest experimental measurements, makes the picture not clear. This brief review covers the current status of CP-violating measurements in the $D^0-bar{D}^0$ system, both on the experimental and theoretical side.
The CDF and DO experiments at the Tevatron $pbar{p}$ collider established that extensive and detailed exploration of the $b$--quark dynamics is possible in hadron collisions, with results competitive and supplementary to those from $e^+e^-$ colliders . This provides a rich, and highly rewarding program that is currently reaching full maturity. I report a few recent world-leading results on rare decays, CP-violation in $B^0_s$ mixing, $bto s$ penguin decays, and charm physics.
We report a measurement of the CP violating asymmetry in $D^0topi^+pi^-$ decays using approximately 215,000 decays reconstructed in about $5.94$ fb$^{-1}$ of CDF data. We use the strong $D^{star +}to D^0pi^+$ decay ($D^{star}$ tag) to identify the flavor of the charmed meson at production time and exploit CP-conserving strong $cbar{c}$ pair-production in $pbar{p}$ collisions. Higher statistic samples of Cabibbo-favored $D^0to K^-pi^+$ decays with and without $D^{star}$ tag are used to highly suppress systematic uncertainties due to detector effects. The result, $Acp(D^0 to pi^{+}pi^{-}) = bigl[0.22pm0.24statpm0.11systbigr]%$, is the worlds most precise measurement to date and it is fully consistent with no CP violation.
Processes involving flavor changing neutral currents (FCNC) provide excellent signatures with which to search for evidence of new physics. They have very small branching fractions in the Standard Model since they are highly suppressed by Glashow-Ilio poulos-Maiani (GIM) mechanism. They occur only through higher order diagrams, and new particles contributions can provide a significant enhancements, which would be an uniquevocal signs of physics beyond the Standard Model. In this paper we present the most recent measurements on FCNC processes performed by CDF and D0 Collaborations, while last section is devote to the charm physics at CDF.
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