We present a search for anomalous production of the signature lepton + photon + b-quark + missing transverse energy (`[gamma]6ETb) produced in $p\bar{p}$ collisions at √ s = 1.96 TeV using 6.0 fb-1 of data taken with the CDF detector in Run II at the Tevatron. In addition to this signature-based search, we present a closely-related search for top pair production with an additional radiated photon, t$\bar{t}$[gamma]. We find 85 `[gamma]6ETb events versus an expectation of 99.1±9.3 events. High-statistics control samples are used to evaluate a low-energy photon [chi] 2 cut. Additionally requiring the events to contain at least three jets, have a total transverse energy of 200 GeV, and that the photon candidate passes the [chi] 2 cut, we observe 30 t$\bar{t}$[gamma] candidate events versus an expectation from non-top Standard Model (SM) sources of 13.0 ± 2.1 Assuming the difference between the observed number and the predicted non-top SM total is due to top production, we measure the tt$\bar{[gamma]}$ cross section to be 0.18 ± 0.08 pb. We also measure the ratio of the t$\bar{t}$[gamma] cross section to the t$\bar{t}$cross section to be 0.024 ± 0.009, which compares well with a SM prediction of 0.024 ± 0.013.

The authors present results of a search in 929 {+-} 56 pb{sup -1} of p{bar p} collisions at 1.96 TeV for the anomalous production of events containing a charged lepton ({ell}, either e or {mu}) and a photon ({gamma}), both with high transverse momentum, accompanied by additional signatures, X, including missing transverse energy (E{sub T}) and additional leptons and photons. They use the same selection criteria as in the previous CDF Run I search, but with an order-magnitude larger data set, a higher p{bar p} collision energy, and the CDF II detector.

The authors present results of a search at CDF in 929 ± 56 pb−1 of p{bar p} collisions at 1.96 TeV for the anomalous production of events containing a high-transverse momentum charged lepton (l, either e or?) and photon , accompanied by missing transverse energy (E{sub T}), and/or additional leptons and photons, and jets (X). They use the same selection criteria as in a previous CDF Run I search, but with an order-magnitude larger data set, a higher p{bar p} collisions energy, and the CDF II detector. They find 163 l?E{sub T} + X events, compared to an expectation of 150.6 ± 13.0 events. They observe 74 ll? + X events, compared to an expectation of 65.1 ± 7.7 events. They find no events similar to the Run II ee??E{sub T} event.

In a search for new phenomena in a signature suppressed in the standard model of elementary particles (SM), we compare the inclusive production of events containing a lepton (l), a photon ([gamma]), significant transverse momentum imbalance (E{sub T}), and a jet identified as containing a b-quark, to SM predictions. The search uses data produced in proton-antiproton collisions at √s = 1.96 TeV corresponding to 1.9 fb−1 of integrated luminosity taken with the CDF detector at the Fermilab Tevatron. We find 28 l[gamma]bE{sub T} events versus an expectation of 31.0{sub -3.5}{sup +4.1} events. If we further require events to contain at least three jets and large total transverse energy, simulations predict that the largest SM source is top-quark pair production with an additional radiated photon, t{bar t} + [gamma]. In the data we observe 16 t{bar t}[gamma] candidate events versus an expectation from non-top-quark SM sources of 11.2{sub -2.1}{sup +2.3}. Assuming the difference between the observed number and the predicted non-top-quark total is due to SM top quark production, we estimate the t{bar t} cross section to be 0.15 ± 0.08 pb.