New particle searches

This review presents recent results on new particle searches achieved at Tevatron, Hera and LEP. After a brief outline of the searches on exotic particles, results on supersymmetric particles and Higgs bosons are detailed. Near future prospects are also given.Comment: 25 pages, 11 postscript figures, typo corrections. To appear in Proceedings of XIX Lepton-Photon Symposium, Stanford, August 199

Model-Independent Global Search for New High-pT Physics at CDF

Data collected in Run II of the Fermilab Tevatron are searched for indications of new electroweak scale physics. Rather than focusing on particular new physics scenarios, CDF data are analyzed for discrepancies with respect to the standard model prediction. A model-independent approach (Vista) considers the gross features of the data, and is sensitive to new large cross section physics. A quasi-model-independent approach (Sleuth) searches for a significant excess of events with large summed transverse momentum, and is particularly sensitive to new electroweak scale physics that appears predominantly in one final state. This global search for new physics in over three hundred exclusive final states in 927 pb^-1 of ppbar collisions at sqrt(s)=1.96 TeV reveals no such significant indication of physics beyond the standard model.Comment: 7 pages. Submitted to Physical Review Letter

Measurement of the polar-angle distribution of leptons from W boson decay as a function of the W transverse momentum in pp[over ¯] collisions at sqrt[s]=1.8 TeV

We present a measurement of the polar-angle distribution of leptons from W boson decay, as a function of the W transverse momentum. The measurement uses an 80±4 pb-1 sample of pp̅ collisions at sqrt[s]=1.8 TeV collected by the CDF detector and includes data from both the W→e+ν and W→μ+ν decay channels. We fit the W boson transverse mass distribution to a set of templates from a Monte Carlo event generator and detector simulation in several ranges of the W transverse momentum. The measurement agrees with the standard model expectation, whereby the ratio of longitudinally to transversely polarized W bosons, in the Collins-Soper W rest frame, increases with the W transverse momentum at a rate of approximately 15% per 10 GeV/c

Searches for new physics in top events at the Tevatron

During the past years the CDF and D0 detectors have collected large amounts of data obtaining a relatively pure sample of pair-produced top quarks and a well understood sample containing singly-produced top quarks. These samples have been used for the precise measurement of the top quark properties, and have set stringent limits on new physics in the top sample. This reports presents the latest results from the CDF and D0 collaborations on the search for new physics within the top sample using an integrated data sample of up to 3.6 fb-1.Comment: Proceedings for the Moriond 2009 QCD sessio

Prospects for top-prime quark discovery at the Tevatron

We show that a top-prime quark as heavy as 600 GeV can be discovered at the Tevatron, provided it is resonantly pair-produced via a vector color octet. If the top-prime originates from a vectorlike quark, then the production of a single top-prime in association with a top may also be observable, even through its decay into a Higgs boson and a top. A color octet with mass of about 1 TeV, which decays into a top-prime pair, may account for the CDF excess of semileptonic (Wj)(Wj) events.Comment: 22 pages, 6 ps figures. v2: Note added about the new D0 search for (Wb)(Wb) resonances; section 4.1 expanded; single-top constraint updated in section 2; references adde

QCD analysis of first b cross section data at 1.96 TeV

The first data on bottom quark production in p-pbar collisions at 1.96 TeV have recently been obtained by the CDF collaboration. These data probe the region of pt~0, providing a new invaluable input on the issue of the compatibility between next-to-leading-order (NLO) QCD and data. We reconsider the evaluation of the b cross section, in view of recent theoretical developments, and of the latest inputs on structure function fits. We show that the new CDF measurements are in good agreement with NLO QCD. If CDF preliminary data are confirmed, a long-standing discrepancy between NLO QCD predictions and hadron-collider data can be settled.Comment: 15 pages, 7 figures. This revision gives an expanded presentation of the results and corrects a mistake in fig 5. V3 updates some reference