Abstract:

The observation of a state consistent with X(3872) decaying into J/ψπ+π- was reported. The X(3872) mass was measured to be 3871.3±0.7(stat)±0.4(syst)MeV/c2 from a sample of 730±90 candidates. The observed width was consistent with the detector resolution. The results were found to be converging well with the measurements by the Belle Collaboration using b± decays.

Abstract:

The decay mechanisms of Bs0 → μ +μ- and Bd0 → μ +μ- in pp̄ collisions were investigated. For discrimination of the decays from background events, four variables were used such as invariant mass of muon pair, B-candidate proper decay length, opening angle between B-hadron flight direction and B-candidate track isolation. A 'blind' analysis technique was also used for determination of optimal selection criteria for four variables. The results show that optimal set of selection criteria uses ∓80 MeV/c2 search window around B s0 mass, and I > 0.65.

Abstract:

The results of a search for the direct production of Kaluza-Klein (KK) graviton modes using the rate of events with one or two energetic jets and large ET at the Collider Detector at Fermilab (CFD) were reported. The search was based on 84±4 pb^-1 of integrated luminosity recorded with the CDF detector. The final state of large missing transverse energy and one or two high energy jets was also investigated. The calculation of graviton emission was based on the effective low-energy theory that was valid below the scale MD.

Abstract:

The search for pair production of scalar top quarks in an R-parity violating supersymmetry scenario in 106 pb-f of pp̄ collisions at √s = 1.8 TeV collected by the Collider Detector at Fermilab was discussed. It was found that in this mode each t1̃ decayed into a τ lepton and a b quark. The events with two τ's, one decaying leptonically and one decaying hadronically and two jets were searched. It was observed that a 95% confidence level lower limit was set on the t 1̄ mass at 122 GeV/c2 for Br(t1̃ → τb).

Abstract:

We present a measurement of the isolated direct photon cross section in [Formula Presented] collisions at [Formula Presented] and [Formula Presented] using data collected between 1994 and 1995 by the Collider Detector at Fermilab (CDF). The measurement is based on events where the photon converts into an electron-positron pair in the material of the inner detector, resulting in a two track event signature. To remove [Formula Presented] and [Formula Presented] events from the data we use a new background subtraction technique which takes advantage of the tracking information available in a photon conversion event. We find that the shape of the cross section as a function of photon [Formula Presented] is poorly described by next-to-leading-order QCD predictions, but agrees with previous CDF measurements. © 2004 The American Physical Society.