1,806 research outputs found
General cost analysis for scholarly communication in Germany : results of the "Houghton Report" for Germany
No full textManagement Summary: Conducted within the project “Economic Implications of New Models for Information Supply for Science and Research in Germany”, the Houghton Report for Germany provides a general cost and benefit analysis for scientific communication in Germany comparing different scenarios according to their specific costs and explicitly including the German National License Program (NLP).
Basing on the scholarly lifecycle process model outlined by Björk (2007), the study compared the following scenarios according to their accounted costs:
- Traditional subscription publishing,
- Open access publishing (Gold Open Access; refers primarily to journal publishing where access is free of charge to readers, while the authors or funding organisations pay for publication)
- Open Access self-archiving (authors deposit their work in online open access institutional or subject-based repositories, making it freely available to anyone with Internet access; further divided into (i) CGreen Open Access’ self-archiving operating in parallel with subscription publishing; and (ii) the ‘overlay services’ model in which self-archiving provides the foundation for overlay services (e.g. peer review, branding and quality control services))
- the NLP.
Within all scenarios, five core activity elements (Fund research and research communication; perform research and communicate the results; publish scientific and scholarly works; facilitate dissemination, retrieval and preservation; study publications and apply the knowledge) were modeled and priced with all their including activities.
Modelling the impacts of an increase in accessibility and efficiency resulting from more open access on returns to R&D over a 20 year period and then comparing costs and benefits, we find that the benefits of open access publishing models are likely to substantially outweigh the costs and, while smaller, the benefits of the German NLP also exceed the costs.
This analysis of the potential benefits of more open access to research findings suggests that different publishing models can make a material difference to the benefits realised, as well as the costs faced. It seems likely that more Open Access would have substantial net benefits in the longer term and, while net benefits may be lower during a transitional period, they are likely to be positive for both ‘author-pays’ Open Access publishing and the ‘over-lay journals’ alternatives (‘Gold Open Access’), and for parallel subscription publishing and self-archiving (‘Green Open Access’). The NLP returns substantial benefits and savings at a modest cost, returning one of the highest benefit/cost ratios available from unilateral national policies during a transitional period (second to that of ‘Green Open Access’ self-archiving). Whether ‘Green Open Access’ self-archiving in parallel with subscriptions is a sustainable model over the longer term is debateable, and what impact the NLP may have on the take up of Open Access alternatives is also an important consideration. So too is the potential for developments in Open Access or other scholarly publishing business models to significantly change the relative cost-benefit of the NLP over time.
The results are comparable to those of previous studies from the UK and Netherlands. Green Open Access in parallel with the traditional model yields the best benefits/cost ratio. Beside its benefits/cost ratio, the meaningfulness of the NLP is given by its enforceability. The true costs of toll access publishing (beside the buyback” of information) is the prohibition of access to research and knowledge for society
Associated Standard Model Higgs Production in ATLAS
No full textThe observation with the ATLAS detector at the LHC of a Standard Model Higgs boson produced in association with ttbar, W or Z bosons, and decaying to WW and bbbar final is reported. Events characterized by the presence of two or three leptons are analyzed to search for the Higgs boson produced in association with vector bosons. Events with two b-tagged jets are selected in association with ttbar topologies. The studies are based on the analysis of Monte Carlo signal and background data simulated in detail through the experimental apparatus
Performance of the ATLAS High Level Trigger in the 2011 and 2012 run
No full textThe ATLAS detector operated during the last 3 years in the LHC beam line, collecting more than 27 fb^-1 of proton-proton events. This allowed researchers to detect a new boson, compatible in many of its properties with the long sought Higgs Boson. One of the main ATLAS components is its complex calorimeter system. This sub-detector is able to detect many of the fundamental processes involved in the physics search. For instance, photon, electron, taus and jets candidates detection as well as missing transverse energy measurement are per- formed using calorimetric information. The calorimeter also plays a central role in the ATLAS trigger system, helping to reduce the large amount of input events (order of 20-30 millions of events per second) to a manageable rate (few hundreds of events per second) recorded for more detailed physics analysis. The trigger system is divided in three levels, the first one implemented in electronic boards and the other two with programs running on a dedicated computing cluster interfaced with the detector electronics. The presentation describes the performance of the tau, jet and missing transverse energy trigger in 2011 and 2012 together with the improvements made to cope with increased luminosity and pile-up condition
Search for H+ -> other states than tau(had)+nu in ATLAS
No full textIn this presentation the searches for a charged Higgs boson are presented, concentrating on two final states with a leptonically decaying tau and lepton/jets and the search for a charged Higgs decaying to csbar. Limits for a doubly charged Higgs from a search for anomalous production of like-sign muon pairs are also presented
Associated Standard Model Higgs boson search with ATLAS
No full textThe observation with the ATLAS detector at the LHC of a Standard Model Higgs boson produced in association with ttbar, W or Z bosons, and decaying to WW and bbbar final is reported. Events characterized by the presence of two or three leptons are analyzed to search for the Higgs boson produced in association with vector bosons. Events with two b-tagged jets are selected in association with ttbar topologies. The studies are based on the analysis of Monte Carlo signal and background data simulated in detail through the experimental apparatus
Search for H± and H±± to other states than tau_had nu
No full textThe presented results of searches for charged Higgs bosons have been performed with the ATLAS detector. An outline of the analyses and the result of the charged Higgs to the tau_lep nu + lepton, tau_lep nu + jets and csbar final state are presented. Upper limits for these searches have been derived. Furthermore the limits for a doubly charged Higgs from a search for anomalous production of like-sign muon pairs are also presented
Performances of the ATLAS High Level Trigger in the 2011 and 2012 run
No full textThe ATLAS detector operated during the last 3 years in the LHC beam line, collecting more than 27 fb−1 of proton-proton events. This allowed researchers to detect a new boson, compatible in many of its properties with the long sought Higgs Boson. One of the main ATLAS components is its complex calorimeter system. This sub-detector is able to detect many of the fundamental processes involved in the physics search. For instance, photon, electron, taus and jets candidates detection as well as missing transverse energy measurement are per- formed using calorimetric information. The calorimeter also plays a central role in the ATLAS trigger system, helping to reduce the large amount of input events (order of 20-30 millions of events per second) to a manageable rate (few hundreds of events per second) recorded for more detailed physics analysis. The trigger system is divided in three levels, the first one implemented in electronic boards and the other two with programs running on a dedicated computing cluster interfaced with the detector electronics. The presentation describes the performance of the tau, jet and missing transverse energy trigger in 2011 and 2012 together with the improvements made to cope with increased luminosity and pile-up conditions. Abstract merged from three abstracts: https://twiki.cern.ch/twiki/pub/Atlas/TDAQSpeakersCommittee2013/CHEF_ATLAS_tau_Trigger.pdf https://twiki.cern.ch/twiki/pub/Atlas/TDAQSpeakersCommittee2013/CHEF2013_HLT_Calo.pdf https://twiki.cern.ch/twiki/pub/Atlas/TDAQSpeakersCommittee2013/CHEF2013_PT_trigger.pd
The ATLAS Trigger Menu: Design and Performance
No full textThe ATLAS trigger is a three-tiered system designed to select events of interest for the diverse ATLAS physics program such as Higgs Boson decays. At the same time the rate of events has to be reduced in order to stay within the limitations of available resources such as the output bandwidth, processing power and recording rate. At design capacity, the LHC has a bunch-crossing rate of 40 MHz whereas ATLAS detector has an average recording rate of about 300Hz. The decision to record an event is based on physics signatures found in the event such as energetic jets, leptons or large missing energy. The ATLAS trigger menu consists of several hundred trigger chains which are used during data taking. Each chain defines the selection criteria at each of the three trigger levels for a single physics signature. Additionally, the trigger menu specifies, depending on the physics purpose of the trigger, at which given rate the trigger is running. The continuously increasing luminosities together with optimisations of algorithms and selection definitions also need to be taken into consideration. We give a description of the trigger menu design for the data taking conditions of 2012 based on previous experience gained for various LHC luminosities that spanned many orders of magnitude in the years 2010 and 2011. We describe how the rates of the various triggers are determined and furthermore discuss the testing and validation of the trigger menu before being used for data taking. The trigger monitoring which can be roughly divided into online and offline monitoring. We describe the various tools used both online and offline to monitor the trigger performance and behaviour, so that quick action can be taken in case of problems
Investigation of the discovery potential of a Higgs boson in the t\bar{t}H^{o}, H^{o} \rightarrow b\bar{b} channel with the ATLAS experiment
No full textThe production of a light Standard Model Higgs boson in association with a
top-quark pair at the Large Hadron Collider (LHC) is studied in a simulation of
the multipurpose ATLAS experiment. The Higgs boson is assumed to decay into a
b\bar{b} pair, and the top-quark pair to decay semi-leptonically. The main background
process for this channel is the production of t\bar{t} events, which can be divided into
reducible and irreducible components. In the process of generating these components
separately, an overlap of events is created through the addition of b-quarks to t\bar{t}
events via parton showering in the t\bar{t}X sample. These events are already included in
the matrix-element cross-section calculation for the t\bar{t}b\bar{b} sample. A new procedure
for the overlap removal is presented in this thesis.
Two analyses are studied, where one aims at the full reconstruction of the nal state
using a cut-based approach. Recently, this way of reconstructing the t\bar{t}H^{o}(H^{o}\rightarrow b\bar{b})
process has been found to be extremely challenging. The other analysis is based
on a new method employing state-of-the-art jet reconstruction and decomposition
techniques where the t\bar{t} pair and the Higgs boson are required to have large transverse
momenta and can therefore be reconstructed as massive Higgs and top jets. A
recent phenomenological study has shown that the t\bar{t}H^{o} process can be recovered
as a promising search channel for a low mass Standard Model Higgs boson around
120 GeV using this approach. Finally, to enhance the sensitivity of the t\bar{t}H^{o} channel,
a combination of the two analyses is presented
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