Tier-2 Computing and Storage for the LHC (GridPP-3)
Lead Research Organisation:
University of Edinburgh
Department Name: Sch of Physics and Astronomy
Abstract
'The Grid' is the next leap in computer interconnectivity. The Internet and the World Wide Web are increasingly an integral part of people's lives, helping the world share information and transfer data quickly and easily. In the same way as we now share files and facts over the global network of computers, in the future the Grid will let us share other things, such as processing power and storage space. The Grid is a practical solution to the problems of storing and processing the large quantities of data that will be produced by industry and the scientific communities over the next decade. Particle physicists are waiting for 2007 when a new particle accelerator opens in the world's largest particle physics laboratory, CERN. The Large Hadron Collider (LHC) will be the most powerful instrument ever built to investigate fundamental physics. Once this is fully functional the amount of data being produced will be massive. All this will be too much for one institution to handle so they need to share resources i.e. to use distributed computing. The Grid is built on the same Internet infrastructure as the web, but uses different tools. Middleware is one of these tools. In a stand alone computer the resources allocated to each job are managed by the operating system e.g. Windows, Linux, Unix, Mac OS X. Middleware is like the operating system of a Grid, allowing users to access resources without searching for them manually. GridPP has developed middleware for the Grid, in collaboration with other international projects. Due to GridPP's open source policy, the middleware can evolve and be improved by the people who use it. Distributed computing has been available to scientists for some time but, in general, the use of different sites has to be negotiated by each scientist individually. They need a separate account on each system and jobs have to be submitted and results collected back by hand. Current distributed computing means the user has a lot of work to do to get their results. This is where the idea of Grid computing comes in. Middleware lets users simply submit jobs to the Grid without having to know where the data is or where the jobs will run. The software can run the job where the data is, or move the data to where there is CPU power available. Using the Grid and middleware, all the user has to do is submit a job and pick up the results. Acting as the gatekeeper and matchmaker for the Grid, middleware monitors the Grid, decides where to send computing jobs, manages users, data and storage. It will check the identity of the user through the use of digital certificates. A digital certificate is a file stored securely on a user's computer which allows the Grid to correctly identify a user. The certificates are given to a user by the Certification Authority, with numerous steps to ensure the person applying is who they say they are. The middleware automatically extracts the users' identity from their digital certificate and uses this to log them in. This means users don't have to remember user names and passwords to log onto the Grid, they're automatically logged on using their Grid certificate. After this seamless identification process the middleware will find the most convenient and efficient places for the job to be run and organise efficient access to the relevant scientific data. It deals with authentication to the different sites being used, runs the jobs, keeps track of progress, lets the user know when the work is complete and transfers the result back.
Organisations
People |
ORCID iD |
Philip Clark (Principal Investigator) | |
Peter Clarke (Co-Investigator) |
Publications
Aad G
(2015)
Two-particle Bose-Einstein correlations in pp collisions at [Formula: see text] 0.9 and 7 TeV measured with the ATLAS detector.
in The European physical journal. C, Particles and fields
Aad G
(2015)
Search for the b b ¯ $$ b\overline{b} $$ decay of the Standard Model Higgs boson in associated (W/Z)H production with the ATLAS detector
in Journal of High Energy Physics
Aad G
(2015)
Search for new phenomena in events with a photon and missing transverse momentum in p p collisions at s = 8 TeV with the ATLAS detector
in Physical Review D
Aad G
(2015)
Searches for heavy long-lived charged particles with the ATLAS detector in proton-proton collisions at s = 8 $$ \sqrt{s}=8 $$ TeV
in Journal of High Energy Physics
Aad G
(2014)
Search for direct production of charginos and neutralinos in events with three leptons and missing transverse momentum in $ \sqrt{s} $ = 8 TeV pp collisions with the ATLAS detector
in Journal of High Energy Physics
Aad G
(2015)
Search for production of vector-like quark pairs and of four top quarks in the lepton-plus-jets final state in pp collisions at s = 8 $$ \sqrt{s}=8 $$ TeV with the ATLAS detector
in Journal of High Energy Physics
Aad G
(2015)
A search for t t ¯ $$ t\overline{t} $$ resonances using lepton-plus-jets events in proton-proton collisions at s = 8 $$ \sqrt{s}=8 $$ TeV with the ATLAS detector
in Journal of High Energy Physics
Aad G
(2016)
A search for prompt lepton-jets in pp collisions at s = 8 $$ \sqrt{\mathrm{s}}=8 $$ TeV with the ATLAS detector
in Journal of High Energy Physics
Aad G
(2014)
Flavor tagged time-dependent angular analysis of the B s 0 ? J / ? ? decay and extraction of ? G s and the weak phase ? s in ATLAS
in Physical Review D
Aad G
(2015)
Study of (W/Z)H production and Higgs boson couplings using H? W W * decays with the ATLAS detector
in Journal of High Energy Physics
Aad G
(2015)
Search for direct pair production of a chargino and a neutralino decaying to the 125 GeV Higgs boson in [Formula: see text] TeV [Formula: see text] collisions with the ATLAS detector.
in The European physical journal. C, Particles and fields
Aad G
(2014)
Search for Higgs boson decays to a photon and a Z boson in pp collisions at s = 7 and 8 TeV with the ATLAS detector
in Physics Letters B
Aad G
(2015)
Search for the X b and other hidden-beauty states in the p + p - ? ( 1 S ) channel at ATLAS
in Physics Letters B
Aad G
(2014)
Search for supersymmetry at $\sqrt{s}$ = 8 TeV in final states with jets and two same-sign leptons or three leptons with the ATLAS detector
in Journal of High Energy Physics
Aad G
(2015)
Search for the Standard Model Higgs boson produced in association with top quarks and decaying into [Formula: see text] in [Formula: see text] collisions at [Formula: see text] with the ATLAS detector.
in The European physical journal. C, Particles and fields
Aad G
(2015)
Search for a new resonance decaying to a W or Z boson and a Higgs boson in the [Formula: see text] final states with the ATLAS detector.
in The European physical journal. C, Particles and fields
Aad G
(2014)
Search for Invisible Decays of a Higgs Boson Produced in Association with a Z Boson in ATLAS
in Physical Review Letters
Aad G
(2014)
Search for direct pair production of the top squark in all-hadronic final states in proton-proton collisions at s $$ \sqrt{s} $$ = 8 TeV with the ATLAS detector
in Journal of High Energy Physics
Aad G
(2015)
Search for invisible decays of the Higgs boson produced in association with a hadronically decaying vector boson in pp collisions at [Formula: see text] TeV with the ATLAS detector.
in The European physical journal. C, Particles and fields
Aad G
(2015)
Search for lepton-flavour-violating H ? µt decays of the Higgs boson with the ATLAS detector
in Journal of High Energy Physics
Aad G
(2015)
Search for Higgs boson pair production in the [Formula: see text] final state from pp collisions at [Formula: see text] TeVwith the ATLAS detector.
in The European physical journal. C, Particles and fields
Aad G
(2015)
Measurement of the inclusive jet cross-section in proton-proton collisions at s = 7 $$ \sqrt{s}=7 $$ TeV using 4.5 fb-1 of data with the ATLAS detector
in Journal of High Energy Physics
Aad G
(2015)
Search for Higgs and Z Boson Decays to J/?? and ?(nS)? with the ATLAS Detector.
in Physical review letters
Aad G
(2014)
Measurement of the underlying event in jet events from 7 $$\text {TeV}$$ TeV proton-proton collisions with the ATLAS detector
in The European Physical Journal C
Aad G
(2016)
Search for flavour-changing neutral current top-quark decays to [Formula: see text] in [Formula: see text] collision data collected with the ATLAS detector at [Formula: see text] TeV.
in The European physical journal. C, Particles and fields
Aad G
(2015)
Measurements of the top quark branching ratios into channels with leptons and quarks with the ATLAS detector
in Physical Review D
Aad G
(2015)
ATLAS Run 1 searches for direct pair production of third-generation squarks at the Large Hadron Collider.
in The European physical journal. C, Particles and fields
Aad G
(2014)
Observation of an excited Bc(±) meson state with the ATLAS detector.
in Physical review letters
Aad G
(2015)
Search for a CP-odd Higgs boson decaying to Zh in pp collisions at s = 8 TeV with the ATLAS detector
in Physics Letters B
Aad G
(2015)
Search for high-mass diphoton resonances in p p collisions at s = 8 TeV with the ATLAS detector
in Physical Review D
Aad G
(2014)
Search for supersymmetry in events with four or more leptons in s = 8 TeV p p collisions with the ATLAS detector
in Physical Review D
Aad G
(2014)
Search for the lepton flavor violating decay Z ? e µ in p p collisions at s = 8 TeV with the ATLAS detector
in Physical Review D
Aad G
(2015)
Summary of the searches for squarks and gluinos using s = 8 $$ \sqrt{s}=8 $$ TeV pp collisions with the ATLAS experiment at the LHC
in Journal of High Energy Physics
Aad G
(2015)
Measurement of charged-particle spectra in Pb+Pb collisions at s N N = 2.76 $$ \sqrt{s_{\mathrm{NN}}}=2.76 $$ TeV with the ATLAS detector at the LHC
in Journal of High Energy Physics
Aad G
(2015)
Measurements of the Nuclear Modification Factor for Jets in Pb+Pb Collisions at v(s)NN]=2.76 TeV with the ATLAS detector.
in Physical review letters
Aad G
(2014)
Search for dark matter in events with a Z boson and missing transverse momentum in p p collisions at s = 8 TeV with the ATLAS detector
in Physical Review D