P. Auchincloss

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}

Abstract The photon structure function F2 has been measured at average Q2 values of 73,160 and 390 ( GeV c ) 2 . We compare the x dependence of the Q2 = 73 ( GeV c ) 2 data with theoretical expectations based on QCD. In addition we present results on the Q2 evolution of the structure function for the intermediate x range (0.3⩽ x ⩽0.8). The results are consistent with QCD.

collisions using semileptonic decay muons

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.

A measurement of the photon structure function F2

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 We have extracted the momentum dependence of the mean, the truncated mean and the most probable value of the energy deposited in a segmented, iron-scintillator, hadron calorimeter by high-energy muons. Data were drawn from a sample of momentum-analyzed, high-energy muons produced in charged-current neutrino interactions. The truncated mean energy deposition of high-energy muons traversing 20 calorimeter segments increases by approximately 16% per 100 GeV c increase in muon momentum over the range 25−125 GeV c ; the most probable energy deposition increases by approximately 7%. These results are important for experiments at high-energy colliders (e.g., Tevatron, SSC and LHC) which use the d E d x of high-energy muons to calibrate the response of electromagnetic and hadron calorimeters with tower geometry. The data are in qualitative agreement with GEANT3 (v3.15/308a) simulations.

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

Abstract We report on a search for the pair production of leptoquarks and colored leptons in e + e − annihilations t center-of-mass energies from 50 to 60.8 GeV, using the AMY detector at TRISTAN. No evidence for such particles is found and 95% CL mass limits are given.

A Study of the energy dependence of the mean, truncated mean, and most probable energy deposition of high-energy muons in sampling calorimeters

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.

A search for leptoquark and colored lepton pair production in e+e- annihilations at TRISTAN

Measurements of neutrino - nucleon and antineutrino - nucleon differential cross sections using the CCFR neutrino detector at Fermilab have been used to extract preliminary values of in the kinematic region 0.01 < x < 0.6 and . The new data provide the first measurements of R in the region x < 0.1. The x and dependence of R is compared with a QCD-based fit to previous data. The QCD fit, which provides an estimate of R in the small-x region where R has not been previously measured, is in good agreement with the new CCFR data.

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

We establish the existence of the top quark using a 67pb{sup {minus}1} data sample of {ital p}{ovr bar}{ital p} collisions at {radical}{ital s}=1.8TeV collected with the Collider Detector at Fermilab (CDF). Employing techniques similar to those we previously published, we observe a signal consistent with {ital tb}{ovr bar}, but inconsistent with the background prediction by 4.8{sigma}. Additional evidence for the top quark is provided by a peak in the reconstructed mass distribution. We measure the top quark mass to be 176{plus_minus}8(stat){plus_minus}10(syst)GeV/{ital c}{sup 2}, and the {ital tt}{ovr bar} production cross section to be 6.8{sub {minus}2.4}{sup +3.6}pb.We establish the existence of the top quark using a 67 pb^-1 data sample of Pbar-P collisions at Sqrt(s) = 1.8 TeV collected with the Collider Detector at Fermilab (CDF). Employing techniques similar to those we previously published, we observe a signal consistent with t-tbar decay to WW b-bbar, but inconsistent with the background prediction by 4.8 sigma. Additional evidence for the top quark is provided by a peak in the reconstructed mass distribution. We measure the top quark mass to be 176 +/-8(stat) +/- 10(sys.) GeV/c^2, and the t-tbar production cross section to be 6.8 +3.6 -2.4 pb.