Made available in DSpace on 2022-04-28T20:18:50Z (GMT). No. of bitstreams: 0 Previous issue date: 2007-08-03; We report the first direct observation of the strange b baryon Ξb-(Ξ̄b+). We reconstruct the decay Ξb-→J/ψΞ-, with J/ψ→μ+μ-, and Ξ-→Λπ-→pπ-π- in pp̄ collisions at s=1.96TeV. Using 1.3fb-1 of data collected by the D0 detector, we observe 15.2±4.4(stat)-0.4+1.9(syst) Ξb- candidates at a mass of 5.774±0.01...
Made available in DSpace on 2022-04-28T20:19:47Z (GMT). No. of bitstreams: 0 Previous issue date: 2007-09-24; Long-lived, heavy particles are predicted in a number of models beyond the standard model of particle physics. We present the first direct search for such particles' decays, occurring up to 100 h after their production and not synchronized with an accelerator bunch crossing. We apply the analysis to the...
Made available in DSpace on 2022-04-28T20:20:42Z (GMT). No. of bitstreams: 0 Previous issue date: 2007-09-28; We present a measurement of the tt̄ pair production cross section in pp̄ collisions at s=1.96TeV utilizing approximately 425pb-1 of data collected with the D0 detector. We consider decay channels containing two high pT charged leptons (either e or μ) from leptonic decays of both top-daughter W bosons. T...
Made available in DSpace on 2022-04-28T20:21:13Z (GMT). No. of bitstreams: 0 Previous issue date: 2007-10-01; We have measured the Λb lifetime using the exclusive decay Λb→J/ψΛ, based on 1.2fb-1 of data collected with the D0 detector during 2002-2006. From 171 reconstructed Λb decays, where the J/ψ and Λ are identified via the decays J/ψ→μ+μ- and Λ→pπ, we measured the Λb lifetime to be τ(Λb)=1.218-0.115+0.130(s...
Made available in DSpace on 2022-04-28T20:32:29Z (GMT). No. of bitstreams: 0 Previous issue date: 2007-10-23; This Letter presents the first strong evidence for the resolution of the excited B mesons B1 and B2* as two separate states in fully reconstructed decays to B+(*)Ï€-. The mass of B1 is measured to be 5720.6Â.±2.4Â.±1.4Â.€‰Â.€ ‰MeV/c2 and the mass difference ÎM between B2* and B1 is 26.2Â.±3.1Â.±0. 9Â.€‰...
Made available in DSpace on 2022-04-28T20:32:56Z (GMT). No. of bitstreams: 0 Previous issue date: 2007-10-30; We report a measurement of the Λb0 lifetime using a sample corresponding to 1.3fb-1 of data collected by the D0 experiment in 2002-2006 during run II of the Fermilab Tevatron collider. The Λb0 baryon is reconstructed via the decay Λb0→μν̄Λc+X. Using 4437±329 signal candidates, we measure the Λb0 lifetim...
Made available in DSpace on 2022-04-28T20:33:49Z (GMT). No. of bitstreams: 0 Previous issue date: 2007-11-05; We report results from a search for the decay Bs0→μ+μ- using 1.3fb-1 of pp̄ collisions at s=1.96TeV collected by the D0 experiment at the Fermilab Tevatron Collider. We find two candidate events, consistent with the expected background of 1.24±0.99, and set an upper limit on the branching fraction of B(...
Made available in DSpace on 2022-04-28T20:34:58Z (GMT). No. of bitstreams: 0 Previous issue date: 2007-11-27; We present a measurement of the top quark pair production cross section in pp̄ collisions at s=1.96TeV utilizing 425pb-1 of data collected with the D0 detector at the Fermilab Tevatron Collider. We consider the final state of the top quark pair containing one high-pT electron or muon and at least four j...
Made available in DSpace on 2022-04-28T20:35:56Z (GMT). No. of bitstreams: 0 Previous issue date: 2007-12-28; We present measurements of the process pp̄→WZ+X→ℓ′ νℓ′ℓ̄ at s=1.96TeV, where ℓ and ℓ′ are electrons or muons. Using 1fb-1 of data from the D0 experiment, we observe 13 candidates with an expected background of 4.5±0.6 events and measure a cross section σ(WZ)=2.7-1.3+1.7pb. From the number of observed ev...
Made available in DSpace on 2022-04-28T20:36:24Z (GMT). No. of bitstreams: 0 Previous issue date: 2008-01-23; Science and Technology Facilities Council; We present a measurement of the muon charge asymmetry from W boson decays using 0.3fb-1 of data collected at s=1.96GeV between 2002 and 2004 with the D0 detector at the Fermilab Tevatron pp̄ Collider. We compare our findings with expectations from next-to-leadi...