5,746 research outputs found
Attitudes of editors of core clinical journals about whether systematic reviews are original research: a mixed-methods study.
In 2009, not all journal editors considered systematic reviews (SRs) to be original research studies, and not all PubMed Core Clinical Journals published SRs. The aim of this study was to conduct a new analysis about editors' opinion regarding SRs as original research.
We conducted a survey and qualitative interview study of journal editors.
All editors listed as editor-in chief of 118 PubMed Core Clinical Journals.
We contacted editors via email and asked them whether they considered SRs original research, whether they published SRs in the journal and, if yes, in which section. We searched PubMed for any SRs (or meta-analyses) published in the included journals in 2017; if we did not find any, we hand-searched these journals. Editors were invited to participate in a follow-up qualitative interview study.
We received responses from 73 editors representing 72 (62%) journals. Fifty-two (80%) editors considered SRs original research, either for any type of SR (65%) or only for SRs with a meta-analysis (15%) and almost all (91%) of editors published SRs. Compared with the results of the 2009 study of Core Clinical Journals, a similar proportion of editors considered SRs to be original studies (71%), accepted SRs as original on certain condition such as presence of meta-analysis (14%) or published SRs (94%). Interviews with editors showed that they used various criteria to decide whether a SR is original research, including methodology, reproducibility, originality of idea and level of novelty.
The majority of editors of core clinical journals consider that SRs are original research. Among editors, there was no uniform approach to defining what makes a SR, or any study, original. This indicates that the concepts of originality of SRs and research are evolving and that this would be a relevant topic for further discussion
QCD
We discuss issues of QCD at the LHC including parton distributions, Monte
Carlo event generators, the available next-to-leading order calculations,
resummation, photon production, small x physics, double parton scattering, and
backgrounds to Higgs production.Comment: 115 pages, Latex, 47 figures, to appear in the Report of the ``1999
CERN Workshop on SM Physics (and more) at the LHC'', S. Catani, M. Dittmar,
D. Soper, W.J. Stirling, S. Tapprogge (convenors
The QCD/SM Working Group: Summary Report
This Report documents the results obtained by the Working Group on Quantum
ChromoDynamics and the Standard Model for the Workshop ``Physics at TeV
Colliders'', Les Houches, France, 21 May - 1 June 2001. The account of
uncertainties in Parton Distribution Functions is reviewed. Progresses in the
description of multiparton final states at Next-to-Leading Order and the
extension of calculations for precision QCD observables beyond this order are
summarized. Various issues concerning the relevance of resummation for
observables at TeV colliders is examined. Improvements to algorithms of jet
reconstruction are discussed and predictions for diphoton and photon pi-zero
production at the LHC are made for kinematic variables of interest regarding
searches for a Higgs boson decaying into two photons. Finally, several
improvements implemented in Monte-Carlo event generators are documented
Standard Model Higgs-Boson Branching Ratios with Uncertainties
We present an update of the branching ratios for Higgs-boson decays in the
Standard Model. We list results for all relevant branching ratios together with
corresponding uncertainties resulting from input parameters and missing
higher-order corrections. As sources of parametric uncertainties we include the
masses of the charm, bottom, and top quarks as well as the QCD coupling
constant. We compare our results with other predictions in the literature.Comment: 32 pages, 4 figures, contribution to LHC Higgs Cross Section Working
Group https://twiki.cern.ch/twiki/bin/view/LHCPhysics/CrossSections,
theoretical uncertainties for H->\mu\mu{} added, version to appear in
European Physical Journal
Detection of very high energy gamma-ray emission from the gravitationally-lensed blazar QSO B0218+357 with the MAGIC telescopes
Context. QSO B0218+357 is a gravitationally lensed blazar located at a
redshift of 0.944. The gravitational lensing splits the emitted radiation into
two components, spatially indistinguishable by gamma-ray instruments, but
separated by a 10-12 day delay. In July 2014, QSO B0218+357 experienced a
violent flare observed by the Fermi-LAT and followed by the MAGIC telescopes.
Aims. The spectral energy distribution of QSO B0218+357 can give information on
the energetics of z ~ 1 very high energy gamma- ray sources. Moreover the
gamma-ray emission can also be used as a probe of the extragalactic background
light at z ~ 1. Methods. MAGIC performed observations of QSO B0218+357 during
the expected arrival time of the delayed component of the emission. The MAGIC
and Fermi-LAT observations were accompanied by quasi-simultaneous optical data
from the KVA telescope and X-ray observations by Swift-XRT. We construct a
multiwavelength spectral energy distribution of QSO B0218+357 and use it to
model the source. The GeV and sub-TeV data, obtained by Fermi-LAT and MAGIC,
are used to set constraints on the extragalactic background light. Results.
Very high energy gamma-ray emission was detected from the direction of QSO
B0218+357 by the MAGIC telescopes during the expected time of arrival of the
trailing component of the flare, making it the farthest very high energy
gamma-ray sources detected to date. The observed emission spans the energy
range from 65 to 175 GeV. The combined MAGIC and Fermi-LAT spectral energy
distribution of QSO B0218+357 is consistent with current extragalactic
background light models. The broad band emission can be modeled in the
framework of a two zone external Compton scenario, where the GeV emission comes
from an emission region in the jet, located outside the broad line region.Comment: 11 pages, 6 figures, accepted for publication in A&
Investigating the peculiar emission from the new VHE gamma-ray source H1722+119
The MAGIC (Major Atmospheric Gamma-ray Imaging Cherenkov) telescopes observed
the BL Lac object H1722+119 (redshift unknown) for six consecutive nights
between 2013 May 17 and 22, for a total of 12.5 h. The observations were
triggered by high activity in the optical band measured by the KVA (Kungliga
Vetenskapsakademien) telescope. The source was for the first time detected in
the very high energy (VHE, GeV) -ray band with a statistical
significance of 5.9 . The integral flux above 150 GeV is estimated to
be per cent of the Crab Nebula flux. We used contemporaneous
high energy (HE, 100 MeV GeV) -ray observations from
Fermi-LAT (Large Area Telescope) to estimate the redshift of the source. Within
the framework of the current extragalactic background light models, we estimate
the redshift to be . Additionally, we used contemporaneous
X-ray to radio data collected by the instruments on board the Swift satellite,
the KVA, and the OVRO (Owens Valley Radio Observatory) telescope to study
multifrequency characteristics of the source. We found no significant temporal
variability of the flux in the HE and VHE bands. The flux in the optical and
radio wavebands, on the other hand, did vary with different patterns. The
spectral energy distribution (SED) of H1722+119 shows surprising behaviour in
the Hz frequency range. It can be modelled
using an inhomogeneous helical jet synchrotron self-Compton model.Comment: 12 pages, 5 figures, 2 table
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