R. Carey

Measurement of bottom quark production in 1.8 TeV

We present a measurement of the [ital b]-quark cross section in 1.8 TeV [ital p]-[ital [bar p]] collisions recorded with the Collider Detector at Fermilab using muonic [ital b]-quark decays. In the central rapidity region ([vert bar][ital y][sup [ital b]][vert bar][lt]1.0), the cross section is 295[plus minus]21[plus minus]75 nb (59[plus minus]14[plus minus]15 nb) for [ital p][sub [ital T]][sup [ital b]][gt]21 GeV/[ital c] (29 GeV/[ital c]). Comparisons are made to previous measurements and next-to-leading order QCD calculations.

p\bar{p}

We present a measurement of jet shapes in [ital [bar p]p] collisions at [radical][ital s] =1.8 TeV at the Fermilab Tevatron using the Collider Detector at Fermilab (CDF). Qualitative agreement is seen with the predictions of recent next-to-leading [[ital O]([alpha][sub [ital s]][sup 3])] calculations and with leading logarithm QCD based Monte Carlo simulations. The dependence of the jet shape on transverse energy is studied.

collisions using semileptonic decay muons

An analysis of {ital W}- and {ital Z}-boson production using data from the Collider Detector at Fermilab at {radical}{ital s} =1.8 TeV yields {sigma}({ital W}{r arrow}{ital ev})/{sigma}({ital Z}{r arrow}{ital ee})=10.2{plus minus}0.8(stat){plus minus}0.4(syst). The width of the {ital W} boson, {Gamma}({ital W}), and a limit on the top-quark mass independent of decay mode are extracted from this measurement.

Measurement of jet shapes in p-barp collisions at sqrt s =1.8 TeV.

We present the dijet invariant-mass distribution in the region between 60 and 500 GeV, measured in 1.8-TeV {ital {bar p}p} collisions in the Collider Detector at Fermilab. Jets are restricted to the pseudorapidity interval {vert bar}{eta}{vert bar}{lt}0.7. Data are compared with QCD calculations; axigluons are excluded with 95% confidence in the region 120{lt}{ital M}{sub {ital A}}{lt}210 GeV for axigluon width {Gamma}{sub {ital A}}={ital N}{alpha}{sub s}{ital M}{sub {ital A}}/6, with {ital N}=5.

Measurement of the ratio sigma (W-->e nu )/ sigma (Z-->ee) in p-barp collisions at sqrt s =1.8 TeV.

Abstract Two large electromagnetic calorimeters have been built for the Collider Detector at Fermilab (CDF). These have been designed for use in the small angle regions in both the proton and the antiproton beam directions. Each calorimeter consists of 30 sampling layers of proportional tube chambers with cathode pad readout separated by lead sheets for a total thickness of 25.5 radiation lengths. Each proportional tube chamber is constructed using a novel technique in which the insulating side of the cathode pad board is bonded to the proportional tube walls using resistive epoxy. The measured energy response of the calorimeter is linear up to 160 GeV, and the measured energy resolution, σ E E , is approximately 25% √E + 0.5% . The position resolution for single electrons varies between 1 and 4 mm depending on location in the calorimeter. The calorimeter offers good e π discrimination, where typically the pion misidentification probability ƒ π → e for an electron identification efficiency ϵ90%.

Two-jet invariant-mass distribution at sqrt s =1.8 TeV.

The production rate of charged {ital D}{sup *} mesons in jets has been measured in 1.8-TeV {ital {bar p}p} collisions at the Fermilab Tevatron with the Collider Detector at Fermilab. In a sample of approximately 32 300 jets with a mean transverse energy of 47 GeV obtained from an exposure of 21.1 nb{sup {minus}1}, a signal corresponding to 25.0{plus minus}7.5(stat){plus minus}2.0(syst) {ital D}{sup *{plus minus}}{r arrow}K{sup {minus plus}}{pi}{sup {plus minus}}{pi}{sup {plus minus}} events is seen above background. This corresponds to a ratio {ital N}({ital D}{sup *+}+D{sup *{minus}})/N(jet) =0.10{plus minus}0.03{plus minus}0.03 for {ital D}{sup *} mesons with fractional momentum {ital z} greater than 0.1.

An electromagnetic calorimeter for the small angle regions of the collider detector at Fermilab

Color coherence effects in [ital p[bar p]] collisions are observed and studied with CDF, the Collider Detector at the Fermilab Tevatron collider. We demonstrate these effects by measuring spatial correlations between soft and leading jets in multijet events. Variables sensitive to interference are identified by comparing the data to the predictions of various shower Monte Carlo programs that are substantially different with respect to the implementation of coherence.

Measurement of D /emph> production in jets from p̅p collisions at √s =1.8 TeV

Color coherence effects in [ital p[bar p]] collisions are observed and studied with CDF, the Collider Detector at the Fermilab Tevatron collider. We demonstrate these effects by measuring spatial correlations between soft and leading jets in multijet events. Variables sensitive to interference are identified by comparing the data to the predictions of various shower Monte Carlo programs that are substantially different with respect to the implementation of coherence.

Evidence for color coherence in [ital p[bar p]] collisions at [radical][ital s] =1. 8 TeV

We report the full reconstruction of χ c mesons through the decay chain χ c → J/ψ γ, J/ψ→μ + m - , using data obtained at the Collider Detector at Fermilab in 2.6±0.2 pb -1 of pp collisions at √s=1.8 TeV. This exclusive χ c sample is used to measure the χ c -meson production cross section times branching fractions. We obtain σ×B=3.2±0.4(stat) -1.1 +1.2 (syst) nb for χ c mesons decaying to J/ψ with p T >6.0 GeV/c and pseudorapidity |η|<0.5

Evidence for color coherence in pp-bar collisions at sqrt s =1.8 TeV.

We present a measurement of the [ital b]-quark cross section in 1.8 TeV [ital p]-[ital [bar p]] collisions recorded with the Collider Detector at Fermilab using muonic [ital b]-quark decays. In the central rapidity region ([vert bar][ital y][sup [ital b]][vert bar][lt]1.0), the cross section is 295[plus minus]21[plus minus]75 nb (59[plus minus]14[plus minus]15 nb) for [ital p][sub [ital T]][sup [ital b]][gt]21 GeV/[ital c] (29 GeV/[ital c]). Comparisons are made to previous measurements and next-to-leading order QCD calculations.