4 research outputs found
Measurement of D+- and D0 production in deep inelastic scattering using a lifetime tag at HERA
The production of D-+/-- and D-0-mesons has been measured with the ZEUS detector at HERA using an integrated luminosity of 133.6 pb(-1). The measurements cover the kinematic range 5 < Q(2) < 1000 GeV2, 0.02 < y < 0.7, 1.5 < p(T)(D) < 15 GeV and |eta(D)| < 1.6. Combinatorial background to the D-meson signals is reduced by using the ZEUS microvertex detector to reconstruct displaced secondary vertices. Production cross sections are compared with the predictions of next-to-leading-order QCD, which is found to describe the data well. Measurements are extrapolated to the full kinematic phase space in order to obtain the open-charm contribution, F-2(c (c) over bar), to the proton structure function, F-2
Multi-Leptons with High Transverse Momentum at HERA
18 pages, 3 figures, revised version with small textual changesEvents with at least two high transverse momentum leptons (electrons or muons) are studied using the H1 and ZEUS detectors at HERA with an integrated luminosity of 0.94 fb^{-1}. The observed numbers of events are in general agreement with the Standard Model predictions. Seven di- and tri-lepton events are observed in e^+p collision data with a scalar sum of the lepton transverse momenta above 100 GeV while 1.94+-0.17 events are expected. Such events are not observed in e^-p collisions for which 1.19+-0.12 are predicted. Total visible and differential di-electron and di-muon photoproduction cross sections are extracted in a restricted phase space dominated by photon-photon collisions
Production of Excited Charm and Charm-Strange Mesons at HERA
The production of excited charm, D 1(2420)0 and D 2 * (2460)0, and charm-strange, D s1(2536)±, mesons in ep collisions was measured with the ZEUS detector at HERA using an integrated luminosity of 126 pb -1. Masses, widths and helicity parameters were determined. The measured yields were converted to the rates of c quarks hadronising as a given excited charm meson and to the ratios of the dominant D 2 * (2460)0 and D s1(2536) ± branching fractions. A search for the radially excited charm meson, D *(2640)±, was also performed. The results are compared with those measured previously and with theoretical expectations
Enhanced interpretation of newborn screening results without analyte cutoff values
A collaboration among 157 newborn screening programs in 47 countries has lead to the
creation of a database of 705,333 discrete analyte concentrations from 11,462 cases affected with
57 metabolic disorders, and from 631 heterozygotes for 12 conditions. This evidence was first
applied to establish disease ranges for amino acids and acylcarnitines, and clinically validate 114
cutoff target ranges.
Objective: To improve quality and performance with an evidence-based approach, multivariate
pattern recognition software has been developed to aid in the interpretation of complex analyte
profiles. The software generates tools that convert multiple clinically significant results into a
single numerical score based on overlap between normal and disease ranges, penetration within
the disease range, differences between specific conditions, and weighted correction factors.
Design: Eighty-five on-line tools target either a single condition or the differential diagnosis
between two or more conditions. Scores are expressed as a numerical value and as the percentile
rank among all cases with the condition chosen as primary target, and are compared to
interpretation guidelines. Tools are updated automatically after any new data submission (2009-
2011: 5.2 new cases added per day on average).
Main outcome measures: Retrospective evaluation of past cases suggest that these tools could
have avoided at least half of 277 false positive outcomes caused by carrier status for fatty acid
oxidation disorders, and could have prevented 88% of false negative events caused by cutoff
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values set inappropriately. In Minnesota, their prospective application has been a major
contributing factor to the sustained achievement of a false positive rate below 0.1% and a
positive predictive value above 60%.
Conclusions: Application of this computational approach to raw data could make cutoff values
for single analytes effectively obsolete. This paradigm is not limited to newborn screening and is
applicable to the interpretation of diverse multi-analyte profiles utilized in laboratory medicine.
Abstract wor