W and Z Cross Sections at the Tevatron

The CDF and D0 experiments at the Tevatron have used p-pbar collisions at sqrt(s)=1.96 TeV to measure the cross section of W and Z boson production using several leptonic final states. An indirect measurement of the total W width has been extracted, and the lepton charge asymmetry in Drell-Yan production has been studied up to invariant masses of 600 GeV/c^2.Comment: 4 pages, 6 figures, proceedings of Moriond QCD 2003, Les Arcs 22-29 march 2003, to be published by World Scientific (ed. T.T.Vanh

Recent Results of the CMS Experiment

The CMS collaboration has recently produced results of a number of searches for new physics processes using data collected during the 2011 run of the Large Hadron Collider. Up to 5 inverse femtobarns of proton-proton collisions at 7 TeV centre-of-mass energy have been used to search for the standard model Higgs boson in five different decay modes, divided in 42 independent sub-channels. The combination of the results has allowed CMS to set 95% confidence-level limits on the Higgs boson mass, constraining it to lay in the region 114.4600 GeV. An excess of events with a local significance of 3.1 standard deviations is observed for M(H)=124 GeV; the global significance of observing such an effect anywhere in the search range 110-600 GeV is estimated to be 1.5 standard deviations. A number of signatures of supersymmetric particles have also been investigated, significantly restricting the parameter space of natural low-scale theories. A search for the rare decays of neutral bottom mesons to muon pairs, Bs to mu mu and Bd to mu mu, has achieved the tightest limits to date, and is approaching the sensitivity to measure the standard model branching ratios. As it happens, though, the highly informative results extracted from 2011 data produce more questions than answers; this doubles expectations for the 2012 run of LHC, which will conclusively answer several of them.Comment: 33 pages, 20 figures. Contribution to the Proceedings of the 50th International Winter Meeting on Nuclear Physics, Bormio (Italy) 23-27 January 201

Observation of Z Decays to b Quark Pairs at the Tevatron Collider

A search for Z boson decays to pairs of b-quark jets has been performed in the full dataset collected with the CDF detector at the Tevatron proton-antiproton collider. After the selection of a pure sample of bb events by means of the identification of secondary vertices from b-quark decays, we have used two kinematic variables to further discriminate the electroweak bb production from QCD processes, and sought evidence for the Z decay in the dijet invariant mass distribution. An absolute background prediction allows the extraction of an excess of events inconsistent with the background predictions by 3.23 sigma but in good agreement with the amount and characteristics of the expected signal. We then fit the mass distribution with an unbinned likelihood technique, and obtain a Z -> bb signal amounting to 91+-30+-19 events.Comment: 12 pages, 8 .eps figure

Charmless and Penguin Decays at CDF

Penguin transitions play a key role in the search of New Physics hints in the heavy flavor sector. During the last decade CDF has been exploring this opportunity with a rich study of two--body charmless decays of neutral B mesons into charged final--state particles. After briefly introducing the aspects of this physics peculiar to the hadron collision environment, I report on two interesting results: the first polarization measurement of the B^0_s --> phi phi decay and the update of the B^0(_s) --> h^+h'^- decays analysis.Comment: 7 pages, 3 figures. Proceedings of CKM2010, the 6th International Workshop on the CKM Unitarity Triangle, University of Warwick, UK, 6-10 September 201

Measurements of the masses, lifetimes and decay modes of hadrons at Tevatron

The Tevatron provides 1.96 TeV ppbar collisions and allows for collection of rich b-hadron samples to the two experiments CDF and D0. The study of heavy flavor properties represents a fruitful opportunity to investigate the flavor sector of the Standard Model (SM) and to look for hints of New Physics (NP). Here we report the first measurement of polarization amplitudes in B^0_s charmless decays, world leading results on b-hadron lifetimes, and measurements of several other properties of b-hadrons.Comment: 4 pages, 2 figures, contribution submitted to 45th Rencontres de Moriond, QCD and High Energy Interactions, La Thuile, March 13-20, 201

Recent heavy flavor results from the Tevatron

The CDF and D0 experiments at the Tevatron ppbar collider have pioneered and established the role of flavor physics in hadron collisions. A broad program is now at its full maturity. We report on three new results sensitive to physics beyond the standard model, obtained using the whole CDF dataset: a measurement of the difference of CP asymmetries in $K^+K^-$ and $\pi^+\pi^-$ decays of $D^0$ mesons, new bounds on the $B^0_s$ mixing phase and on the decay width difference of $B^0_s$ mass-eigenstates, and an update of the summer 2011 search for $B^0_(s)$ mesons decaying into pairs of muons. Finally, the D0 confirmation of the observation of a new hadron, the $\chi_b(3P)$ state, is briefly mentioned.Comment: 4 pages, 2 figures, contribution submitted to 47th Rencontres de Moriond, QCD and High Energy Interactions, La Thuile, March 10-17, 201