Jet Physics at the Tevatron

Results are presented from analyses of jet data produced in pbarp collisions at $\sqrt{s}$ = 1960 GeV collected with the DZero and CDF detectors during 2002--03 at the Fermilab Tevatron Collider. Preliminary measurements of the inclusive jet cross section, the dijet mass spectrum, and jet structure are presented.Comment: Invited talk at the XXIII Physics in Collisions Conference (PIC03), Zeuthen, Germany, June 2003, 10 pages, LaTeX, 18 eps figures. SAAT0

Charge Asymmetries in Semileptonic B Decays

I present measurements made by the D0 collaboration of the time-integrated flavor-specific semileptonic charge asymmetry in the decays of the Bs and Bd mesons that have undergone flavor mixing, asls and asld, using 10.4 fb^-1 of proton-antiproton collisions collected by the D0 detector during Run II at the Fermilab Tevatron Collider. The results are asls = [-1.12 \pm 0.74 (stat) \pm 0.17 (syst) ]% and asld = [0.68 \pm 0.45 (stat.) \pm 0.14 (syst.)]% which are the two most precise published results and are in agreement with standard model predictions. These results are combined with the like-sign dimuon charge asymmetry, aslb, and recent preliminary results from the LHCb and BaBar experiments to obtain new world averages.Comment: 7 pages, 5 figures. To appear in Proc. 14th Int. Conf. on B-Physics at Hadron Machines (Beauty 2013), Bologna, Italy, April 8-12, 201

McRunjob: A High Energy Physics Workflow Planner for Grid Production Processing

McRunjob is a powerful grid workflow manager used to manage the generation of large numbers of production processing jobs in High Energy Physics. In use at both the DZero and CMS experiments, McRunjob has been used to manage large Monte Carlo production processing since 1999 and is being extended to uses in regular production processing for analysis and reconstruction. Described at CHEP 2001, McRunjob converts core metadata into jobs submittable in a variety of environments. The powerful core metadata description language includes methods for converting the metadata into persistent forms, job descriptions, multi-step workflows, and data provenance information. The language features allow for structure in the metadata by including full expressions, namespaces, functional dependencies, site specific parameters in a grid environment, and ontological definitions. It also has simple control structures for parallelization of large jobs. McRunjob features a modular design which allows for easy expansion to new job description languages or new application level tasks.Comment: CHEP 2003 serial number TUCT00

Combined search for the Higgs boson with the D0 experiment

We perform a combination of searches for standard model Higgs boson production in $p\bar{p}$ collisions recorded by the D0 detector at the Fermilab Tevatron Collider at a center of mass energy of $\sqrt{s}=1.96$ TeV. The different production and decay channels have been analyzed separately, with integrated luminosities of up to 9.7 fb$^{-1}$ and for Higgs boson masses $90\leq M_H \leq 200$ GeV. We combine these final states to achieve optimal sensitivity to the production of the Higgs boson. We also interpret the combination in terms of models with a fourth generation of fermions, and models with suppressed Higgs boson couplings to fermions. The result excludes a standard model Higgs boson at 95% C.L. in the ranges $90 M_HM_

Search for ZH to llbb production in 4.2 fb^-1 of ppbar collisions at sqrt(s) = 1.96 TeV

We present a search for the standard model Higgs boson produced in association with a Z boson in 4.2 fb^-1 of p-pbar collisions, collected with the D0 detector at the Fermilab Tevatron at sqrt(s) = 1.96 TeV. Selected events contain one reconstructed Z to llbb candidate and at least two jets, including at least one b-tagged jet. In the absence of an excess over the background expected from other standard model processes, limits on the ZH cross section multiplied by the branching ratios are set. The limit at M_H = 115 GeV is a factor of 5.9 larger than the standard model prediction

Search for the standard model Higgs boson in ZH -> l+ l- bbbar production with the D0 detector in 9.7 fb-1 of ppbar collisions at sqrt(s)=1.96 TeV

We present a search for the standard model (SM) Higgs boson produced in association with a Z boson in 9.7 fb-1 of ppbar collisions collected with the D0 detector at the Fermilab Tevatron Collider at sqrt(s) = 1.96 TeV. Selected events contain one reconstructed Z-> e+e- or Z-> mu+mu- candidate and at least two jets, including at least one jet identified as likely to contain a b quark. To validate the search procedure, we also measure the cross section for ZZ production in the same final state. It is found to be consistent with its SM prediction. We set upper limits on the ZH production cross section times branching ratio for H->bbbar at the 95% C.L. for Higgs boson masses 9

Observation of a narrow mass state decaying into Upsilon(1S) + gamma in ppbar collisions at sqrt(s) = 1.96 TeV

Using data corresponding to an integrated luminosity of 1.3 fb^-1, we observe a narrow mass state decaying into Upsilon(1S)+gamma, where the Upsilon(1S) meson is detected by its decay into a pair of oppositely charged muons, and the photon is identified through its conversion into an electron-positron pair. The significance of this observation is 5.6 standard deviations. The mass of the state is centered at 10.551 \pm 0.014 (stat.) \pm 0.017 (syst.) GeV/c^2, which is consistent with that of the state recently observed by the ATLAS Collaboration

Search for a fourth generation t' quark in ppbar collisions at sqrt{s}=1.96 TeV

We present a search for pair production of a fourth generation t' quark and its antiparticle, followed by their decays to a W boson and a jet, based on an integrated luminosity of 5.3/fb of proton-antiproton collisions at sqrt{s}=1.96 TeV collected by the D0 Collaboration at the Fermilab Tevatron Collider. We set upper limits on the t't'bar production cross section that exclude at the 95% C.L. a t' quark that decays exclusively to W+jet with a mass below 285 GeV. We observe a small excess in the muon+jets channel which reduces the mass range excluded compared to the expected limit of 320 GeV in the absence of a signal