Measurement of the diffractive cross section in deep inelastic scattering using ZEUS 1994 data
European Physical Journal C 6:1 (1999) 43-66
Abstract:
The DIS diffractive cross section, dσdiffγ*p→XN/dMx, has been measured in the mass range Mx < 15 GeV for γ*p c.m. energies 60 < W < 200 GeV and photon virtualities Q2 = 7 to 140 GeV2. For fixed Q2 and Mx, the diffractive cross section rises rapidly with W, dσdiffγ*p→X N (Mx, W, Q2)/dMx ∝ Wadiff with adiff = 0.507 ± 0.034 (stat) +0.155-0.046 (syst) corresponding to a t-averaged pomeron trajectory of ̄αℙ = 1.127 ± 0.009 (stat) +0.039-0.012 (syst) which is larger than ̄αℙ observed in hadron-hadron scattering. The W dependence of the diffractive cross section is found to be the same as that of the total cross section for scattering of virtual photons on protons. The data are consistent with the assumption that the diffractive structure function FD(3)2 factorizes according to cursive greek chiℙFD(3)2(cursive greek chiℙ, β, Q2) = (cursive greek chi0//cursive greek chiℙ)nFD(2)2(β, Q2). They are also consistent with QCD based models which incorporate factorization breaking. The rise of cursive greek chiℙFD(3)2 with decreasing cursive greek chiℙ and the weak dependence of FD(2)2 on Q2 suggest a substantial contribution from partonic interactions.Measurement of the high-mass drell-yan cross section and limits on quark-electron compositeness scales
Physical Review Letters 82:24 (1999) 4769-4774
Abstract:
We present a measurement of the Drell-Yan cross section at high dielectron invariant mass using 120 pb-1 of data collected in pp collisions at √ s = 1.8 TeV by the D0 Collaboration during 1992-1996. No deviation from standard model expectations is observed. We use the data to set limits on the quark-electron compositeness scale. The 95% confidence level lower limits on the compositeness scale vary between 3.3 and 6.1 TeV depending on the assumed form of the effective contact interaction. © 1999 The American Physical Society.Measurement of the top quark pair production cross section in the all-jets decay channel
Physical Review Letters 83:10 (1999) 1908-1913
Abstract:
We present a measurement of t¯t production in p¯p collisions at √s = 1.8TeV from 110pb-1 of data collected in the all-jets decay channel with the D0 detector at Fermilab. A neural network analysis yields a cross section of 7.1 ± 2.8(stat) ± 1.5(syst)pb at a top quark mass (mt) of 172.1GeV/c2. Using previous D0 measurements from dilepton and single lepton channels, the combined D0 result for the t¯t production cross section is 5.9 ± 1.2(stat) ± 1.1(syst)pb for mt = 172.1GeV/c2. © 1999 The American Physical Society.Measurement of the top quark mass in the dilepton channel
Physical Review D Particles Fields Gravitation and Cosmology 60:5 (1999)
Abstract:
We report a measurement of the top quark mass using six candidate events for the process (Formula presented), observed in the D0 experiment at the Fermilab (Formula presented) collider. Using maximum likelihood fits to the dynamics of the decays, we measure a mass for the top quark of (Formula presented). We combine this result with our previous measurement in the (Formula presented) channel to obtain (Formula presented) as the best value of the mass of the top quark measured by D0. © 1999 The American Physical Society.Search for charged higgs bosons in decays of top quark pairs
Physical Review Letters 82:25 (1999) 4975-4980