Rapid reviews and the methodological rigor of evidence synthesis: a JBI position statement

The demand for rapid reviews has exploded in recent years. A rapid review is an approach to evidence synthesis that provides timely information to decision-makers (eg, health care planners, providers, policymakers, patients) by simplifying the evidence synthesis process. A rapid review is particularly appealing for urgent decisions. JBI is a world-renowned international collaboration for evidence synthesis and implementation methodologies. The principles for JBI evidence synthesis include comprehensiveness, rigor, transparency, and a focus on applicability to clinical practice. As such, JBI has not yet endorsed a specific approach for rapid reviews. In this paper, we compare rapid reviews versus other types of evidence synthesis, provide a range of rapid evidence products, outline how to appraise the quality of rapid reviews, and present the JBI position on rapid reviews. JBI Collaborating Centers conduct rapid reviews for decision-makers in specific circumstances, such as limited time or funding constraints. A standardized approach is not used for these cases;instead, the evidence synthesis methods are tailored to the needs of the decision-maker. The urgent need to deliver timely evidence to decision-makers poses challenges to JBI's mission to produce high-quality, trustworthy evidence. However, JBI recognizes the value of rapid reviews as part of the evidence synthesis ecosystem. As such, it is recommended that rapid reviews be conducted with the same methodological rigor and transparency expected of JBI reviews. Most importantly, transparency is essential, and the rapid review should clearly report where any simplification in the steps of the evidence synthesis process has been taken

The ΛΛ and Ξ- p mass spectra produced by 2.2 GeV/c K- interactions on nuclei

The S = -2 dibaryon states ΛΛ and Ξ- p have been studied with more than double previous statistics. Earlier indications of an enhancement at MΛΛ = 2.37 GeV/c2 are not confirmed. © 1975.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

The interaction and decay of K--mesons in photographic emulsion - Part III

This paper presents Part III of the series on the interaction of K--mesons in photographic emulsions contributed by the European K-collaboration. The mean free path for K--interaction in flight (10÷80) MeV with hydrogen and with the complex nuclei in emulsion are compared with other recent experimental data. A number of Σ-hyperons are also investigated. From favourable examples of Σ+-p decay recorded in the emulsion the Σ+ mass is estimated as MΣ=2327.2±1.0 mc and from the hydrogen capture (K-+H) events the mass difference (MΣ--MΣ+) is found to be 14.6±1.1 me. Lifetime estimates are also given for the charged Σ hypersons:a) The best estimate for the Σ+ lifetime is obtained using only events in which the decay proton is emitted forward in the centre-of-mass system. Thus τ+=0.82-0.20+0.34·10-10 s. b) A representative value for the hypothetical Σ- lifetime as determined from 70 selected Σπ± decays is 0.71-0.12+0.19·10-10 s. The effective lifetime appears (as well as can be ascertained) to remain of the order of the Σ;+ lifetime, even in samples containing widely different proportions of Σ- hyperons. Although values are greater than the lifetimes previously reported in emulsion esperiments, it still appears possible that a genuine anomaly may exist. The observed numbers of secondary interactions by charged particles emitted from the K--capture stars may be accounted for on the basis of proton interactions, although some contribution from deuterons is not excluded. One definite example of a fast Σ interaction (visible energy release 129 MeV) has been found in a length of 70 cm of track registered in the emulsion. The number of single scatterings in 18 cm of Σ- and 25 cm of Σ+ hyperon track in emulsion (energy interval (5÷100) MeV) are compared with that expected for Coulomb scattering by a point nucleus. Only a slight possible indication of the nuclear interaction of the Σ--hyperon is demonstrated with the few data at present available. In K--interactions giving (Σ+π) some 45 Σp+ and 47 Σπ+ decays were also examined for possible polarization of the decay with respect to the (Σ, π) plane of production. © 1960 Società Italiana di Fisica.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

The masses of the Ξ hyperons

Using a 2.1 GeV/c K - exposure in a heavy liquid bubble chamber, the masses of the Ξ hyperons have been measured to be M(Ξ 0) = 1315.2 ± 0.9 MeV/c 2 and M(Ξ -) = 1321.12± 0.41 MeV/c 2. Their mass difference is compared to theoretical predictions. © 1972.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

The interaction of K--mesons with photographic emulsion nuclei - Part II. The emission of hyperons from K--interactions at rest

The emission of Σ-hyperons from 3 037 K- capture stars at rest in nuclear emulsion has been studied. The identification of the hyperons is discussed. Charged Σ-hyperons are emitted from (17.6±1.0)% of all K--stars while (9.6±0.6)% of them lead to the emission of both Σ-hyperons and π-mesons. The Σ-/Σ+ ratio for all stars is 0.86±0.12 while for stars in which a π-meson is also emitted it is 0.45±0.10. The difference between this latter value and the markedly different value (2.0) obtained for K--interactions at rest in a hydrogen bubble chamber is attributed to the Fermi motion of nucleons in the nucleus, and a dependence of the relative K- transition amplitudes on the energy of relative motion of the K--meson and nucleon. The branching ratio, R, of the number of Σ+ decays to π+ and proton respectively is 1.23±0.27. The stable prong distribution of the stars in which a hyperon is emitted, as well as the energy distribution of the Σ-hyperons at emission has been studied. About 16% of all identified charged Σ-hyperons had an emission energy above 60 MeV, and had to be attributed to multi-nucleon interactions of the K--meson. It is estimated that the proportion of all multi-nucleon primary capture prccesses may be as high as (30÷40)%. The interaction of a K--meson with a pair of neutrons seems to occur rarely, if at all. From the fraction of Σ+ emitting stars which also emit a π--meson it is concluded that only about 10% of the π--mesons fail to escape from the nucleus in which capture occurs. This could be understood if K--capture occurs predominantly in the peripheral region of the nucleus. From a similar study of Σ- emitting stars it is found however that the proportion of π+ or π0-mesons, or both, that are absorbed in the nucleus is much higher. Estimates are made of the mean free path in nuclear matter of Σ-hyperons and π0-mesons. Most of the one-nucleon interactions leading to Σ-hyperon production take place with protons and the transition amplitudes corresponding to the T=1 state of isotopic spin is smaller than the T=0 transition amplitude. © 1959 Nicola Zanichelli Editore.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

The interaction and decay of K- mesons in photographic emulsion - Part I. General characteristics of K--Interactions and analysis of events in which a charged π-meson is emitted

A total of 3 480 K--mesons has been observed. Of these 445 interact in flight, at a mean energy of 40 MeV and only their general characteristics have been studied. Little difference has been observed between the number of unstable charged particles (Σ±-hypersons and π±-mesons) in these interactions and those in the 3 035 interactions at rest. The 3 035 K--interactions at rest have been studied in detail. In this paper (Part I) are given the results on those interactions in which π-mesons are emitted. An estimate of the Σ-hyperon nuclear potential is based on the energy spectrum of π-mesons emitted in the K--interactions in which the only charged particles emitted are a π-meson and a Σ-hyperon. A detailed examination of the angular distribution of 2-pronged events, and of the sign ratio of the π-mesons, the prong distribution and energy release in all events has led to an estimate of the probabilities of absorption of positive and negative Σ-hyperons in the parent nucleus, and to a partition of the events between the various primary reactions. © 1959 Società Italiana di Fisica.SCOPUS: ar.jinfo:eu-repo/semantics/publishe