Dr Farrukh Azfar

Abstract:

We present results of searches for diphoton resonances produced both inclusively and also in association with a vector boson (W or Z) using 100 pb-1 of pp̄ collisions using the CDF detector. We set upper limits on the product of cross section times branching ratio for both pp̄→γγ+X and pp̄→γγ+ W/Z. Comparing the inclusive production to the expectations from heavy sgoldstinos we derive limits on the supersymmetry-breaking scale √F in the TeV range, depending on the sgoldstino mass and the choice of other parameters. Also, using a NLO prediction for the associated production of a Higgs boson with a W or Z boson, we set an upper limit on the branching ratio for H → γγ. Finally, we set a lower limit on the mass of a "bosophilic" Higgs boson (e.g., one which couples only to γ, W, and Z bosons with standard model couplings) of 82 GeV/c2 at 95% confidence level. ©2001 The American Physical Society.

Abstract:

Double diffraction differential cross sections in pp collisions at √s = 1800 and 630 GeV were measured. Results were compared with data at √s = 200 and 900 GeV and with predictions based on Regge theory and factorization. A factorization breakdown comparable in magnitude to that observed in single diffraction dissociation was found. The data are in agreement with the renormalized gap probability model.

Abstract:

An overview is given on the measurements of dσ/dM and improvement of the existing measurements of AFB. All the measurements have been taken by the Collider Detector at Fermilab (CDF). The measurements of e+e- pairs with invariant masses between 40 and 500 eV/c2 complement measurements in e+e- machines, that currently extend to 200 GeV/c2.

Abstract:

The first measurement of the true top quark PT distributon was carried out. An attempt was also made to compute a 95% confidence level upper limit on the fraction of top quarks that are produced with 225 > PT > 425 GeV/c. It was found that R4 > 0.16 at 95% C.L.

Abstract:

We report on a search for the supersymmetric partner of the top quark (top squark) produced in tt̄ events using 110 pb-1 of pp̄ collisions at √s = 1.8 TeV recorded with the Collider Detector at Fermilab. In the case of a light top squark, the decay of the top quark into a top squark plus the lightest supersymmetric particle (LSP) could have a significant branching ratio. The observed events are consistent with standard model tt̄ production and decay. Hence, we set limits on the branching ratio of the top quark decaying into a top squark plus LSP, excluding branching ratios above 45% for a LSP mass up to 40 GeV/c2.