ATLAS control room

A summer evening in the ATLAS control room

4th August 2015The sun has already set over Geneva when I finally walk out from the ATLAS control room. We have been waiting for beams to be injected into the machine since the early hours of the afternoon, but without much success so far. Just a regular day for the most ambitious particle accelerator mankind has ever built, but a pretty boring afternoon for our entire shift crew.

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ATLAS Overview Week in Marrakech in 2013

From ATLAS Around the World: Brief history of Morocco in ATLAS

31st July 2015In 1996, Morocco officially became a member of the ATLAS collaboration. The eagerly awaited day had finally arrived, and the first Arabic and African country signed a collaborative agreement with CERN to participate in the great scientific adventure of particle physics.

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Average ATLAS charged-particle multiplicity

Physics and Performance With 13 TeV Proton Collisions

30th July 2015 – After a shutdown of more than two years, Run 2 of the Large Hadron Collider (LHC) has restarted with proton–proton collisions at a centre-of-mass energy of 13 TeV. This new phase will allow the LHC experiments to explore nature and probe the physical laws governing it at scales never reached before.

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This new result at 13 TeV (red circle) is compared to previous results from ATLAS

Top quarks in Run 2 are spot on

27th July 2015With a precision of just under 14% − currently dominated by our ability to understand how many proton-proton collisions have occurred at ATLAS (i.e. luminosity) − this measurement is able to confirm that quantum chromodynamics, the theory of the strong interaction, still seems to be going strong! 

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Murrough Landon and Manuel discussing results from the beam splashes

From ATLAS Around the World: Triggers (and dark) matter

27th July 2015To the best of our knowledge, it took the Universe about 13.798 billion years to allow funny looking condensates of mostly oxygen, carbon and hydrogen to ponder on their own existence. Some particularly curious specimens became scientists, founded CERN, dug several rings into the ground near Geneva, Switzerland, built the Large Hadron Collider, and also installed a handful of large detectors along the way.

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Lepton transverse momentum distribution from the W→ μν selection

Of mesons and bosons

24th July 2015ATLAS is ready for detailed physics studies. The experiment used early data collected from the LHC’s Run 2 to calibrate its detectors. Measurements of the production and leptonic decay of certain particle resonances have shown that the detectors and software are working as expected. 

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Inclusive-jet cross sections as a function of the jet pT

First measurements set the stage for early searches of new physics

24th July 2015Jets are collimated sprays of hadrons generated from quarks and gluons, produced either directly in the proton-proton collision or as a part of the decay of W bosons, Z bosons, Higgs bosons, top quarks or new particles yet to be discovered. In fact, all W, Z and Higgs bosons decay most often to quarks which form jets. 

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Two-particle correlations

ATLAS measurements of the ridge in proton-proton collisions at 13TeV

24th July 2015Previous studies of two-particle angular correlations in proton-proton, proton-lead, and lead-lead collisions at the LHC have provided important insight on the physics of the particle production process. On 24 July, Atlas presented new preliminary measurements of two-particle correlations...

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The average charged-particle multiplicity as a function of the centre-of-mass energy

Early Run 2 results test event generator energy extrapolation

22nd July 2015On 23 July 2015, ATLAS presented its first measurements of soft strong interaction processes using charged particles produced in proton–proton collisions at 13 TeV centre-of-mass energy delivered by the Large Hadron Collider at CERN. These measurements were performed with a dataset collected beginning of June under special low-luminosity conditions.

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EPS-HEP 2015

First Run 2 Results to be Presented at EPS

20th July 2015 – The first results using the record-breaking Run 2 data will be presented at the European Physical Society conference on High Energy Physics (EPS-HEP) in Vienna, 22-29 July. It will be an exciting opportunity to see how these first few weeks of data-taking have progressed.

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Musical Dimensions

9th July 2015 – CERN will be back at the Montreux Jazz Festival for its third annual workshop: 'The Physics of Music and The Music of Physics' on 9 July at 15:00 in Petit Palais. Live events from the ATLAS experiment mapped into music will feature as part of the event. Run 2 of the LHC began this spring, bringing with it hopes and promise of new physics and discovery. One of many key items on the LHC shopping list is the existence of new spatial dimensions, a potential means to harmonise gravity in our theoretical understanding of nature.

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Music of the 'LHC'

4th July 2015 – The ATLAS & CMS experiments celebrate the second anniversary of the discovery of the Higgs boson. Here, are some images of the path from the LHC's startup to the Nobel Prize, featuring a musical composition by Roger Zare, performed by the Donald Sinta Quartet, called 'LHC'. Happy Discovery Day!

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Workers assembling the ATLAS SemiConductor Tracker

From ATLAS Around the World: Working with Silicon in Japan

3rd July 2015I joined the ATLAS experiment in 2012 after graduating from the University of Tokyo, however my previous experience was completely different from collider physics. During my Master’s course, I focused on the behaviour of a kind of silicon detector operated in Geiger mode. At that time, the experiments at CERN looked like a “castle” to me.

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ATLAS Awards Long Shutdown 1 Achievements

25th June 2015 – The ATLAS Outstanding Achievement Awards 2015 were presented on 18 June to 26 physicists and engineers, in 11 groups, for their excellent work carried out during Long Shutdown 1 (LS1).

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From ATLAS Around the World: Faster and Faster!

24th June 2015 – Faster and Faster! This is how it gets as soon as LS1 ends and the first collisions of LHC Run 2 approaches. As you might have noticed, at particle physics experiments we LOVE acronyms! LS1 stands for the first Long Shutdown of the Large Hadron Collider.

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Projecting pARTicles in Cuba

22nd June 2015 – From Ars Electronica-style festivals to artists in residence programmes at scientific organisations, "art meets science" is a term that just keeps on trending. ATLAS visiting artist Agnes Chavez has taken a fresh look at the merging of the disciplines, adding a new one to the mix: "Art meets Science meets Education".

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Display of one of the events selected as a candidate W’ event decaying to WZ.

Run I search for new massive bosons builds excitement for Run II

19th June 2015The ATLAS experiment is now taking data from 13 TeV proton-proton collisions. The increased collision energy and rate in these Run 2 collisions will allow physicists to carry out stronger tests of many theoretical conjectures, including several theories that predict more massive versions of force-carrying particles like the W and Z bosons.

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Impressions from the Control Room

17th June 2015 – As final preparations were made for the start of the Large Hadron Collider's (LHC) Run 2, the ATLAS Control Room was the centre of activity. Here are images from the three days that were landmark events...

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ATLAS Proton-Proton Collision at 13 TeV

Setting Off To New Energy Horizons

4th June 2015After a shutdown of more than two years, Run 2 of the Large Hadron Collider (LHC) is restarting at a centre-of-mass energy of 13 TeV for proton–proton collisions and increased luminosity. This new phase will allow the LHC experiments to explore nature and probe the physical laws governing it at scales never reached before.

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ATLAS Begins Recording Physics Data at 13 TeV

3rd June 2015 – Today ATLAS and other particle physics experiments at CERN's Large Hadron Collider (LHC) began recording physics data from 13 TeV proton collisions, which allow for precision studies of the Higgs boson and other Standard Model particles, as well as the search for new particles with higher masses. The new data will bring a deeper understanding of nature.

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