Dr Farrukh Azfar

Abstract:

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 300 exclusive final states in 927pb-1 of pp̄ collisions at s=1.96TeV reveals no such significant indication of physics beyond the standard model. © 2008 The American Physical Society.

Abstract:

We report on a search for narrow-width particles decaying to a top and antitop quark pair. The data set used in the analysis corresponds to an integrated luminosity of 680pb-1 collected with the Collider Detector at Fermilab in run II. We present 95% confidence level upper limits on the cross section times branching ratio. Assuming a specific top-color-assisted technicolor production model, the leptophobic Z′ with width ΓZ′=0.012MZ′, we exclude the mass range MZ′<725GeV/c2 at the 95% confidence level. © 2008 The American Physical Society.

Abstract:

We describe a measurement of the W boson mass mW using 200pb-1 of s=1.96TeV pp̄ collision data taken with the CDF II detector. With a sample of 63964 W→eν candidates and 51128 W→μν candidates, we measure mW=[80.413±0.034(stat)±0.034(sys)=80.413±0.048]GeV/c2. This is the single most precise mW measurement to date. When combined with other measured electroweak parameters, this result further constrains the properties of new unobserved particles coupling to W and Z bosons. © 2008 The American Physical Society.