Physics Analysis Expert PAX: First Applications

PAX (Physics Analysis Expert) is a novel, C++ based toolkit designed to assist teams in particle physics data analysis issues. The core of PAX are event interpretation containers, holding relevant information about and possible interpretations of a physics event. Providing this new level of abstraction beyond the results of the detector reconstruction programs, PAX facilitates the buildup and use of modern analysis factories. Class structure and user command syntax of PAX are set up to support expert teams as well as newcomers in preparing for the challenges expected to arise in the data analysis at future hadron colliders.Comment: Talk from the 2003 Computing in High Energy and Nuclear Physics (CHEP03), La Jolla, Ca, USA, March 2003, 7 pages, LaTeX, 10 eps figures. PSN THLT00

Measurement of the t(t)over-bar production cross section in p(p)over-barcollisions at root s=1.96 TeV using kinematic fitting of b-tagged lepton plus jet events

We report a measurement of the t (t) over bar production cross section using the CDF II detector at the Fermilab Tevatron. The data consist of events with an energetic electron or muon, missing transverse energy, and three or more hadronic jets, at least one of which is identified as a b-quark jet by reconstructing a secondary vertex. The background fraction is determined from a fit of the transverse energy of the leading jet. Using 162 +/- 10 pb(-1) of data, the total cross section is found to be 6.0 +/- 1.6(stat.)+/- 1.2(syst.) pb, which is consistent with the standard model prediction

Measurement of the mass difference m(D-s(+))-m(D+) at CDF II

We present a measurement of the mass difference m(D-s(+))-m(D+), where both the D-s(+) and D+ are reconstructed in the phipi(+) decay channel. This measurement uses 11.6 pb(-1) of data collected by CDF II using the new displaced-track trigger. The mass difference is found to be m(D-s(+))-m(D+)=99.41+/-0.38(stat)+/-0.21(syst) MeV/c(2)

Search for the flavor-changing neutral current decay D-0 -\u3emu(+)mu(-) in p(p)over-bar collisions at root s=1.96 TeV

We report on a search for the flavor-changing neutral current decay D-0--\u3emu(+)mu(-) in p (p) over bar collisions at roots=1.96 TeV using 65 pb(-1) of data collected by the CDF II experiment at the Fermilab Tevatron Collider. A displaced-track trigger selects long-lived D-0 candidates in the D-0--\u3emu(+)mu(-) search channel, the kinematically similar D-0--\u3epi(+)pi(-) channel used for normalization, the Cabibbo-favored D-0--\u3eK(-)pi(+) channel used to optimize the selection criteria in an unbiased manner, and their charge conjugates. Finding no signal events in the D-0--\u3emu(+)mu(-) search window, we set an upper limit on the branching fraction B(D-0--\u3emu(+)mu(-))less than or equal to2.5x10(-6) (3.3x10(-6)) at the 90% (95%) confidence level

Measurement of prompt charm meson production cross sections in p(p)over-bar collisions at root s=1.96 TeV

We report on measurements of differential cross sections d sigma/d p_t for prompt charm meson production in p anti-p collisions at s**(1/2) = 1.96 TeV using 5.8 +/- 0.3 pb-1 of data from the CDF II detector at the Fermilab Tevatron. The data are collected with a new trigger that is sensitive to the long lifetime of hadrons containing heavy flavor. The charm meson cross sections are measured in the central rapidity region |y| \leq 1 in four fully reconstructed decay modes: D0 --> K- pi+, D*+ -> D0 pi+, D+ --> K- pi+ pi+, D+_s--> phi pi+, and their charge conjugates. The measured cross sections are compared to theoretical calculations.Comment: Minor changes of the text and reference for the publicatio