Large expert-curated database for benchmarking document similarity detection in biomedical literature search

Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency–Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research

Electroweak parameters of the z0 resonance and the standard model

Contains fulltext : 124399.pdf (publisher's version ) (Open Access

The reaction e+ e- ---> gamma gamma (gamma) at Z0 energies

The total and differential cross-sections for the reaction e+e- → γγ(γ) are measured at centre of mass energies around 91 GeV using an integrated luminosity of 4.7 pb-1. The aggreement with QED prediction is good. Consequently there is no evidence for non-standard channels which would have the same experimental signature. The lower limits on the QED cuttoff parameters are Λ+ > 113 GeV and Λ- > 95 GeV. An upper limit on the effective coupling between a possible excited electron and the gamma is derived. At 95% confidence level the branching ratios for Z0 decay into π0γ, ηψ and γγγ are below 1.5 × 10-4, 2.8 × 10-4 and 1.4 × 10-4 respectively.0info:eu-repo/semantics/publishe

Search for the t and b′ quarks in hadronic decays of the Z0 boson

[Abstract

MEASUREMENT OF THE AVERAGE LIFETIME OF B-HADRONS

The average lifetime of B hadrons produced in hadronic Z0 decays has been measured with the DELPHI detector at LEP. The measurement is based on the analysis of the impact parameter distribution of high p(t) muons and hadrons. The resulting mean B lifetimes are tau(B) = (1.30 +/- 0.10 +/- 0.08) ps and tau(B) = (1.27 +/- 0.04 +/- 0.12) ps respectively, giving a combined value of tau(B) = (1.28 +/- 0.10) ps. The hadronic sample was also used to measure the partial Z0 width GAMMA(bbBAR)/GAMMA(h) and gave a value of 0.222(-0.031)+0.033 +/- 0.017

STUDY OF ORIENTATION OF 3-JET EVENTS IN Z(0) HADRONIC DECAYS USING THE DELPHI DETECTOR

The study of the orientation of three-jet events from e+ e- –> Z0 –> multi-hadrons is presented, in particular the polar angle distributions of the thrust axis and of the normal to the three-jet plane, and the azimuthal correlations between the hadron plane and the one defined by the beam and thrust axes. The data are compared with results at lower energy and with QCD predictions. Good agreement with QCD predictions is observed. The scalar gluon theory is excluded by the data

ENERGY ENERGY CORRELATIONS IN HADRONIC FINAL-STATES FROM Z0 DECAYS

We have studied the energy-energy angular correlations in hadronic final states from Z0 decay using the DELPHI detector at LEP. From a comparison with Monte Carlo calculations based on the exact second order QCD matrix element and string fragmentation we find that Lambda-MS(5) = 104(-20)+25(stat.)-20(+25)(syst.)-00(+30)(theor.) MeV, which corresponds to alpha-s(91 GeV) = 0.106 +/- 0.003(stat.) +/- 0.003(syst.)-0.000(+0.003)(theor.). The theoretical error stems from different choices for the renormalization scale of alpha-s. In the Monte Carlo simulation the scale of alphA-s as well as the fragmentation parameters have been optimized to described reasonably well as aspects of multihadron production