Run 1

Improving our understanding of photon pairs

High-energy photon pairs at the LHC are famous for two things. First, as a clean decay channel of the Higgs boson. Second, for triggering some lively discussions in the scientific community in late 2015, when a modest excess above Standard Model predictions was observed by the ATLAS and CMS collaborations.

5th April 2017

Weighing in on the top quark mass

ATLAS has released a new precise measurement of the mass of the top quark, the heaviest known elementary particle.

15th June 2016

Chasing after elusive B meson decays into muons

Almost four years following the discovery of the Higgs boson, LHC experiments are now more than ever exploring the possibility of new particles and new effects beyond the Standard Model.

22nd March 2016

ATLAS presents new results at Moriond conference

This year’s 50th anniversary edition of the “Moriond Electroweak and Unified Theories” conference at La Thuile in Italy featured the presentation and discussion of first results from the LHC full-year 2015 data samples (“Run 2”) collected by the LHC experiments at unprecedented 13 TeV proton-proton collision energy.

21st March 2016

ATLAS presents new top physics results

This week, physicists from around the world are gathering at the Top 2015 workshop in Ischia, Italy to discuss the latest measurements of the top quark. As the heaviest known fundamental particle, the top quark plays a special role in the search for "new physics".

17th September 2015

Run 1 search for new massive bosons builds excitement for Run 2

The 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.

19th June 2015

A week of firsts

The annual conference, Moriond, is in its 50th edition this year, and I’ve had the pleasure of coming down to Aosta in Italy to participate in the QCD session; for the first time. It’s actually a week of firsts for me. The conference organizers described it as being in a kind of “QCD confinement”.

7th April 2015
7th April 2015

ATLAS further verifies Standard Model coupling/mass relationship of Higgs boson

The discovery of a Higgs Boson in 2012 by the ATLAS and CMS experiments marked a key milestone in the history of particle physics. It confirmed a long-standing prediction of the Standard Model, the theory that underlines our present understanding of elementary particles and their interactions.

27th March 2015

The scalar boson

The ATLAS experiment has released results confirming that the Higgs boson has spin 0 (it is a so-called “scalar”) and positive parity as predicted by the Standard Model, making it the only elementary scalar particle to be observed in nature.

26th March 2015

In search of rare Higgs boson production with top quarks

In proton-proton collisions, several processes can lead to the production of a Higgs boson. The most “frequent” process (which is about one collision in four billion!) is the fusion of two gluons, contained in the initial protons, into a Higgs boson through a “top-quark loop”. Least frequent is a mode where the Higgs boson is produced in association with a pair of top-quarks.

24th March 2015

Latest ATLAS results on the Higgs Boson

On 17 March, ATLAS presented their latest Higgs physics results at an LHC seminar at CERN from data collected during the LHC's first run. The updated results include searches for the Higgs boson in association with top quarks, measurements of the spin and parity, and improved and combined coupling measurements, all showing good compatibility with Standard Model predictions. These results are also being presented at the 50th Rencontres de Moriond ElectroWeak conference, in La Thuile, Italy, this week.

19th March 2015

Looking at the Dark side of Matter

The search continues for dark matter, a new kind of matter that doesn’t emit or absorb light. It is assumed to account for the missing amount of mass in our Universe. The total mass in our Universe can be inferred from the observation of gravitational effects of stars in galaxies, and galaxies in clusters of galaxies. However the amount of mass calculated from the observed distribution of light is much less. It is proposed that dark matter makes up the discrepancy as it does not emit light.

19th February 2015

In search of super charm

If all the experimental evidence supports a theory, why should anyone want to dream up additional particles? Yet exactly this situation arose in the late 1960s. At that time, when the complete table of the known hadrons could be explained with just three quarks, theorists were already proposing a fourth, which they whimsically called “charm”.

9th January 2015

The Art of Rediscovery

When I tell people I’m a particle physicist, one of the most frequent questions I get asked is: “So, have you discovered anything?” Funnily, I’ve spent much of the past two years trying to rediscover something that’s already been seen before. In today’s world, which fetishizes the New, this may seem slightly lame, but just because we’ve discovered something, doesn’t mean we’ve fully understood it.

7th January 2015

Quenching jets in the hot dense matter produced by colliding lead ions

The Large Hadron Collider is known to collide protons, but for one month a year, beams of lead ions are circulated in the 27-km tunnel and made to collide in the centre of the experiments. The ATLAS experiment has made new precise measurements of the suppression of jets as they blast through the dense matter created by the lead ion collisions.

13th November 2014

New ATLAS precision measurements of the Higgs boson: Observation of WW decay

The Standard Model makes many different predictions regarding the production and decay properties of the Higgs boson, most of which can be tested at the Large Hadron Collider (LHC). Since the discovery, experimentalists from the ATLAS collaboration have analysed the complete dataset recorded in 2011 and 2012, have improved the calibration of the detector, and have increased substantially the sensitivity of their analyses.

7th October 2014

Searches for new physics with photons produced at vertices displaced from the collision point

Theories, such as supersymmetry, propose the existence of new types of particles to explain important questions about the universe, such as the nature of dark matter. ATLAS has performed a search for one such type – exotic heavy particles that have lifetimes long enough that they travel partway through the detector before decaying, at what is called a displaced vertex.

22nd September 2014

ATLAS finds evidence for the rare electroweak W±W± production

The Standard Model of particle physics has been extremely successful in predicting a vast variety of phenomena – so successful, that it is easy to forget that some of its predictions have not yet been verified. A very important one, related intimately to electroweak symmetry breaking, is that the gauge bosons (γ, W and Z) can interact with each other through quartic interactions.

10th September 2014

First observation of Z-boson production via weak-boson fusion

The fusion of two weak bosons is an important process that can be used to probe the electroweak sector of the Standard Model. Measurements of Higgs production via weak-boson fusion are crucial for precise extraction of the Higgs-boson couplings and have the potential to help pin down the charge conjugation and parity of the Higgs boson. A similar process, weak-boson scattering, is sensitive to alternative electroweak symmetry-breaking models and to anomalous weak-boson gauge couplings. These processes are extremely rare and the experimental observation of the production of heavy bosons via weak-boson fusion has become possible only recently with the large centre-of-mass energy and luminosity provided by the LHC. Extracting the signals from the huge backgrounds in the high pile-up conditions at the LHC is a major challenge.

10th September 2014

Higgs boson production measurements from the channels of discovery

The discovery of the Higgs boson by the ATLAS and CMS collaborations in 2012 marked a new era in particle physics because it completed the Standard Model and gave us another tool to explore territories beyond. The Standard Model predicts precisely the interactions of the Higgs boson to all other elementary particles once its mass is measured.

10th September 2014

Probing Higgs boson production properties

ATLAS has measured properties of events likely to contain a Higgs boson, in order to get a better understanding of the frequency and manner in which they are produced. The study specifically examines the fiducial and differential cross sections for Higgs bosons that decay into two photons or into two Z bosons, using proton-proton collisions recorded by ATLAS in 2012.

17th July 2014

The Higgs boson’s shadow

ATLAS physicists have studied the “shadow” of the Higgs boson far above its mass peak in an analysis of the full sample of 8 TeV proton-proton collisions delivered by the LHC in 2012. The study involves Higgs boson decays into two Z bosons, which themselves decay into four charged leptons or two charged leptons plus two neutrinos. Among other interesting properties, it provides new insight into the lifetime, or natural width, of the Higgs boson.

14th July 2014

The WW cross-section: a high flyer

The production of pairs of heavy bosons, such as two Z bosons, a Z and a W boson, or the more challenging pair of W bosons (WW), are processes that particle physicists are passionate about because they cover a rich spectrum of phenomena. The WW channel, in particular, represents a substantial experimental challenge. In the events considered for this measurement, each W boson decays into an electron or a muon plus a neutrino that remains undetected and is reconstructed through the presence of missing energy in the event.

8th July 2014

Are quarks fundamental particles?

From decades of discoveries made at particle colliders, we know that protons are composed of quarks bound together by gluons. We also know that there are six kinds of quarks, each one with its associated antiparticle. But are quarks fundamental? ATLAS searched for signs that quarks may have substructure in its most recent data, collected from the LHC’s proton-proton collisions in 2012.

6th July 2014

Hunting for the top squark

Completion of the analysis of 2012 data recorded by the ATLAS detector at the LHC’s collision energy of 8 TeV has significantly improved our capability of finding a supersymmetric partner of the top quark – also known as the top squark or the stop.

5th July 2014

A new state of beauty and charm

ATLAS has observed a particle state of mass and decay properties consistent with expectations for an excited state of the Bc meson. The discovery follows analysis of the full 7 TeV and 8 TeV proton-proton collision data sets from the LHC’s first run.

5th July 2014

The production of W bosons in association with jets

The production of a W boson in association with “jets” of particles initiated by quarks or gluons (“W+jets” events) is an important signature to test quantum chromodynamics, the theory of strong interactions. A new measurement reported by ATLAS focuses on studying the properties of the jets in a large data sample of W+jets events.

5th July 2014

Counting collisions with ALFA

Data from a special run of the LHC using dedicated beam optics at 7 TeV have been analysed to measure the total cross-section of proton-proton collisions in ATLAS. Using the Absolute Luminosity For ATLAS (ALFA), a Roman Pot sub-detector located 240 metres from the collision point, ATLAS has determined the cross-section with unprecedented precision to be σtot (pp → X) = 95.4 ± 1.4 millibarn.

5th July 2014

Precise measurement of the Higgs boson mass

The ATLAS Collaboration has analyzed its full Run 1 data sample of seven and eight TeV (tera electron Volts) proton-proton collisions delivered by the Large Hadron Collider (LHC), to produce an accurate measurement of the Higgs boson mass. The Higgs boson resonance appears as a narrow peak in the mass spectra of its decays to two photons or to four charged leptons, as shown in the two figures below.

3rd July 2014

New evidence for top quark pairs produced with W or Z bosons

Evidence for the production of a W or Z boson together with a top quark pair, referred to as tt̄W and tt̄Z processes, has been found in the ATLAS analysis of the 8 TeV data from the LHC’s first run.

3rd July 2014

Measuring top production in the LHC

Using the full data sample from the LHC’s first run of proton-proton collisions, ATLAS has measured the production rate of top and anti-top quarks.

3rd July 2014

Higgs Mass to String Balls

ATLAS presented new results at the Large Hadron Collider Physics (LHCP) Conference in Columbia University, New York, 2 to 7 June. Many new searches and improved measurements were presented, among which were an updated Higgs boson mass measurement, a search for double Higgs boson production and new searches for Supersymmetry and exotic phenomena.

6th June 2014

No matter how hard you try... Standard is standard

The past two days of the Recontres de Moriond 2014 Electroweak conference have been very intense with many new experimental results, many insightful theoretical talks and many lively discussions. Since the topics cover neutrino experiments, astrophysical observations and Standard Model precision measurements, giving a summary is not an easy task. But I will try.

22nd March 2014

The Penguin Domination

This week features the 2014 Moriond Electroweak conference at La Thuile, Italy. More than a 100 particle physicists gather from all around the world. Started 50 years ago, this conference is still very valued, year after year, due to the high quality of the talks. The Moriond winter conference is one of the most exciting conferences, as all the particle physics experiments present their brand new results, but it is also appealing because of the mountains and the great Italian food.

18th March 2014

Higgs into fermions

The ATLAS experiment released preliminary results on 26 Nov 2013 that show evidence, with a significance of 4.1 standard deviations that the Higgs boson decays to two taus, which are fermions. This is exciting news. But what makes this measurement important?

26th November 2013
26th November 2013

So where is all the SUSY?

Supersymmetry (SUSY) is one of the most loved, and most hated, theories around that works as an extension of our beloved Standard Model.

4th October 2013

New results on the properties of the top quark

At the EPS HEP conference today, ATLAS released a new precise measurement of the top quark mass using events where both top quarks decay via W bosons to electrons or muons. ATLAS also presented limits on the possibility of the top quark decaying to channels not foreseen in the Standard Model. A comparison of the behaviour of top quarks and anti-top quarks produced at the LHC is in agreement with the prediction of the Standard Model, disfavouring models of new physics that require a large top/anti-top asymmetry.

19th July 2013

What we learned from ATLAS at Les Rencontres de Moriond 2013

Les Rencontres de Moriond, an important conference for the worldwide community of particle physicists, took place from 2-16 March 2013 in La Thuile, Italy. Of all the scientists present, 22 ATLAS physicists had been invited to reveal the experiment's latest findings. What did we learn from this new ATLAS physics harvest?

8th April 2013

ATLAS in the Italian Alps for the Rencontres de Moriond 2013

From March 2nd to March 16th 2013 the mythic "Rencontres de Moriond" is taking place in the Italian Alps at the La Tuile ski resort. For the 48th edition of this famous event, more than 420 physicists, theorists and experimentalists, young and more experienced, coming from the four corners of the planet get together in this pleasant environment to share their most recent results and ideas on particle physics. Twenty-two ATLAS physicists were invited to divulge the latest findings of the ATLAS Experiment.

27th February 2013

ATLAS in the Land of the Rising Sun for HCP 2012

From November 12th to November 16th, more than 250 particle physicists are gathering in Kyoto, Japan to share their latest results. One of the key international particle physics conferences of the year, the Hadron Collider Physics Symposium 2012 (HCP 2012), will take place this year in the Land of the Rising Sun.

9th November 2012

TOP 2012 - Part 2

Welcome back, dedicated top quark enthusiast. I’m sure you’ve all been waiting on the edge of your seats for an update from TOP 2012, and I can now confirm that a combined team of LHC & Tevatron physicists narrowly beat a mixed team of physicists from LHC & Tevatron at croquet.

26th September 2012
26th September 2012

TOP 2012 - Part 1

Greetings from the TOP 2012 conference, Winchester UK! What’s a ‘Winchester’ I hear you asking? A type of gun? Indeed yes, though sadly not of the smoking variety that we’re all so keen to find. However in this particular case Winchester is a historical town in the south of England, complete with the typical rolling green fields, a cathedral, and the not so typical contingent of visiting physicists!

18th September 2012
18th September 2012

The Physics of Top Quarks

The 5th International Workshop on Top Quark Physics (TOP2012) will take place in Winchester, UK, from the 16th to the 21st of September. It will gather experts in the field of top quark physics as well as PhD students and will highlight the newest results and topics related to the physics of top quarks.

11th September 2012
11th September 2012

What should we know about the Higgs particle?

On the 4th of July, CERN announced the discovery of a new particle that can be interpreted as the Higgs boson with both the ATLAS and CMS experiments. Since this is one of the most important discoveries over the last 10 or 20 years in particle physics, let’s have a look to the full story.

15th August 2012

ATLAS Supersymmetry Searches and More at SUSY 2012 in Beijing

The 20th International Conference on Supersymmetry and Unification of Fundamental Interactions (SUSY 2012) is taking place in Beijing, China on 13 -18 August 2012. SUSY is the theory which, if confirmed by experiment, will be the high energy extension of the Standard Model (SM). In SUSY, every particle should have a massive "shadow" particle or super-partner. Experimentalists have been looking for years for proof of the existence of these SUSY particles or sparticles.

13th August 2012

ATLAS Higgs Search Update

On 31 July, 2012, the ATLAS Experiment submitted a scientific paper describing the discovery of a new particle consistent with the Higgs Boson to the journal Physics Letters B.

31st July 2012

ATLAS Results Presented Down Under at ICHEP 2012

Every other year, particle physicists gather together to share their latest results at the ICHEP (International Conference on High Energy Physics) conference. This year, more than 700 are attending the conference in Melbourne, Australia, July 4-11.

9th July 2012

Latest ATLAS Results to be Presented Down Under at ICHEP 2012

Every other year, particle physicists gather together to share their latest results at the ICHEP (International Conference on High Energy Physics) conference. This year, more than 700 are attending the conference in Melbourne, Australia, July 4-11.

2nd July 2012

ATLAS to Present Updated Higgs Analysis Results in Upcoming Joint CERN / ICHEP Seminar

The ATLAS Experiment will be presenting its most recent results from searches for the Higgs Boson at the LHC in a dedicated seminar to be held at CERN on 4 July at 9:00 CET.

29th June 2012

Quark Excitement: Is there anything smaller?

The Large Hadron Collider commands many superlatives. One of the most useful of these is that the LHC is our planet's most powerful human-built microscope. The higher the collision energy, the tinier the distances you can study.

23rd May 2012

Moriond day 3: The day of the Higgs

(I'm not skipping day 2, about heavy flavors and my own talk, but I think today's topic merits a reshuffling)

8th March 2012

Moriond day 2: Inverse time dilation

I work with crazy particles. Dark matter is pretty weird, so are neutrinos seemingly, but what I search for blows it all away. Tuesday was the day of my presentation. The format for these young scientist presentations are 5 minutes and time for a single question afterwards. Trying to present a full picture of any analysis in that short a time is impossible; instead the idea is more like handing out a business card telling the audience what you work on in the hope that some will be interested and contact you informally afterwards.

6th March 2012

Moriond day 1: The outer limits

Not many trips take you to all ends of the world in one day, but that was nevertheless how it felt after the first talks at Moriond. Sunday and Monday have mainly featured presentations on neutrino and dark matter physics. Many of these experiments are placed in remote regions or deep under ground.

5th March 2012

Mountains of Physics

Experimentalists and theorists are gathering once more in the Alps at La Thuile, Italy, March 3-17 for the annual "Rencontres de Moriond" to discuss latest results in particle physics and cosmology.

5th March 2012

Mystical Moriond

As a young physicist not many conferences have the same mystical status as Rencontres de Moriond. This gathering of physicists from all areas of particle physics is one of most anticipated events of the year. More a gathering than a conference, Moriond started in 1966 and has inspired many similar events. Presentations, time for discussion and recreation is combined to inspire and foster collaboration and new ideas. Another element is the meeting between young and more experienced scientists. Nearly half of the talks are given by young participants below 35 like myself. I was invited by the ATLAS collaboration to present our latest results on a search for a type of long-lived particles that has meant a lot to me for the last two years.

3rd March 2012
3rd March 2012

7 or 8 TeV, a thousand terabyte question!

A very happy new year to the readers of this blog. As we start 2012, hoping to finally find the elusive Higgs boson and other signatures of new physics, an important question needs to be answered first - are we going to have collisions at a center of mass energy of 7 or 8 TeV?

11th February 2012

Tweeting live #Higgs boson updates from #CERN

“If it’s just a fluctuation of background, it will take a lot of data to kill.” Dr. Fabiola Gianotti, spokesperson for the ATLAS collaboration, made this statement on Dec. 13, 2011 during a special seminar I attended at CERN. Within the minute that followed, I hurriedly concocted a tweet, tacked on #Higgs and #CERN hashtags, and sent Fabiola’s weighty comment out onto the WWW.

11th February 2012

Higgs search papers submitted for publication

The results on Standard Model (SM) Higgs searches that ATLAS reported at a CERN seminar on December 13, 2011, have now been submitted for publication in three papers.

7th February 2012

ATLAS discovers its first new particle

The ATLAS collaboration has announced the discovery of the χb(3P), which is a bound state of a bottom quark and bottom antiquark (bbar).

22nd December 2011

The ATLAS and CMS combination of Higgs search results

The Higgs Boson is the only missing piece in the Standard Model of particle physics and its search is undoubtedly one of the most important searches in the history of physics. The Higgs boson is the generator of all elementary particle masses in nature. The mass of the Higgs boson itself is unknown, and before the LHC it was searched for in previous experiments but not found. LHC experiments have produced excellent results since the start of the data taking. In ATLAS and CMS a discussion was initiated about a year ago to combine the Higgs search results from both experiments. The framework and the procedure to combine results had to be defined and agreed upon before the combined analysis could proceed.

1st December 2011

ATLAS and CMS combine summer '11 search limits on the Standard Model Higgs

Perhaps the most anticipated result of the LHC involves the search for the Higgs boson, the only particle predicted by the Standard Model (SM) that has not yet been seen by experiments. The Higgs boson helps explain how elementary particles acquire mass. If the SM Higgs boson exists it will be produced at the LHC and swiftly decay into various known and well-studied particles, with the dominant decay products depending on the actual Higgs mass. ATLAS and CMS search for the SM Higgs boson using a range of decay products: two photons; two tau leptons; two b quarks; two W bosons; and two Z bosons. Analysing all these channels ensures that the search is sensitive to observing the Higgs irrespective of its mass.

18th November 2011

ATLAS reveals latest results at HCP11

The ATLAS Experiment presented its latest results at the Hadron Collider Physics Symposium 2011 in Paris, France (14-18 November). Many of the most recent searches and analyses are based on more than double the data available at the last big conference in August.

16th November 2011

ATLAS au pays du Soleil levant pour HCP 2012

Du 12 au 16 novembre, plus de 250 physiciens des particules se réuniront à Kyoto, au Japon, pour partager leurs plus récents résultats. L'une des conférences internationales de physique des particules les plus prisées de l'année, le Hadron Collider Physics Symposium 2012 (HCP 2012), aura lieu, cette année, au pays du Soleil levant.

9th November 2011

ATLAS reaches milestone: 5 inverse femtobarns of data!

In an amazing year that has exceeded our expectations, the Large Hadron Collider has delivered, and ATLAS has recorded, over 5 inverse femtobarns (fb-1) of collisions. These units correspond to having 3.4 x 1014 or 340 000 000 000 000 total collisions. Most analyses presented at the last major conference (the Lepton Photon Symposium in August in Mumbai) made use of about 1 fb-1, so this is a big jump.

28th October 2011

Higgs results from Lepton Photon

The Lepton Photon 2011 conference began on Monday in Mumbai, India. Over 400 physicists from all over the world (including me!) gathered to hear the latest results. One result in particular -- news on the search for the Higgs boson -- was foremost in people's minds, and rather than prolong the suspense further, the talks on the Higgs were scheduled right after the welcoming speeches.

26th August 2011

ATLAS advances in the search for the Higgs and New Physics

The ATLAS experiment has continued to record data and to refine the analyses in the search for the Higgs boson and many other exciting signatures of new physics. The latest results are being presented at the Lepton Photon 2011 symposium in Mumbai, India, 22-27 August 2011. Since the previous meeting (the European Physical Society — EPS, Grenoble, France, 21-27 July 2011), the LHC has almost doubled the data provided to ATLAS.

22nd August 2011

ATLAS Presents New Results at Lepton Photon 2011

The ATLAS Collaboration is pleased to be presenting its latest results at the Lepton Photon 2011 conference in Mumbai 22-27 August 2011.

18th August 2011

A look back at the EPS

I happened to run into Andrey Korytov after his eagerly awaited CMS Higgs talk. No, CMS had not yet seen the Higgs, and ATLAS could breathe a sigh of relief.

30th July 2011

A view inside the ATLAS Higgs combination

Well it's been a few days since the Higgs presentations at EPS, and I'm just recovering from the lack of sleep. It's ironic that I have a newborn daughter, and my sleep deprivation is due to work.

28th July 2011

Arrival at EPS

When I was invited to give a talk on behalf of ATLAS at this summer’s European Physical Society High Energy Physics conference (EPS), I wasn’t really sure what to expect. Most conferences I have been to are relatively intimate affairs where you have long discussions after every talk and then everybody trots down to the pub together to discuss the day’s results. EPS, though, is one of the largest particle physics conferences in the world. Or at least I reckon it is, having eyeballed the number of participants registered on the website, hailing from all sorts of fields ranging from astrophysics to ultra relativistic ions to our very own LHC proton-proton collider physics.

28th July 2011
28th July 2011

ATLAS results revealed at EPS HEP 2011 conference in Grenoble

Many members of the ATLAS Experiment Collaboration have been at the European Physical Society's HEP 2011 conference in Grenoble, France, this week, revealing the results of 35 new and exciting physics analyses for the very first time.

27th July 2011

A Search for New Physics Processes using Dijet Events

The ATLAS Experiment has extended the energy frontier of searches for new particles and new processes beyond those of the Standard Model by studying collision events with so-called "dijets".

21st June 2011

Is Nature Supersymmetric?

String Theory predicts a new symmetry, called "supersymmetry", that could shed light on some of today's mysteries of fundamental particles and interactions. In supersymmetry, every particle-type should have a "shadow" particle called a super-partner that (in general) has a much higher mass. The ATLAS Experiment has analyzed the first year of its LHC data and searched for evidence of these super-partners of ordinary matter.

24th May 2011

The inverse picobarn threshold has been crossed in ATLAS!

Another milestone has been passed in the long run of ATLAS toward new physics. On Monday August 9, 2010 ATLAS has recorded the first inverse picobarn (pb-1) of 7 TeV collisions. The trend is good and we recently reached the 0.1 pb-1 per day of integrated luminosity (meaning that we can now collect in ~10 days the amount of data we have collected over the last 4 months).

10th August 2010

Sleepless Nights Lead to First Results of 2010...

Do you hear that? The incessant typing? The coffee machines vending cup after cup? If you go to Building 40, or Building 32, Building 188, or to any one of the many graduate student offices around the world, you will hear the tap of key boards, the whir of disk drives, and even the occasional heated civil discussions with "elevated" voices.

6th June 2010

How will it happen?

So how will this whole "First 7 TeV Collisions" event happen? Well, here is my (somewhat naive) understanding of what will happen.

28th March 2010
28th March 2010

ATLAS Experiment Reports Its First Physics Results from the LHC

The first physics results from the ATLAS Experiment with proton-proton collisions at an energy of 0.9 TeV in late 2009 have now been accepted for publication in the journal Physics Letters B.

17th March 2010

First collisions in ATLAS

A few days ago, loud cheers and happy faces filled the ATLAS Control Room while the whole detector lit up: protons are back at the experiment's door, and everybody forgot in a second the long year of waiting for the Large Hadron Collider (LHC) to resume operation.

23rd November 2009

LHC beams and events back in ATLAS

Loud cheers and happy faces fill the ATLAS Control Room while the whole detector lights up: protons are back today at the experiment's door, and everybody forgets in a second the long year of waiting for the Large Hadron Collider (LHC) to resume operation.

21st November 2009

First beam and first events in ATLAS

ATLAS experimenters celebrated today as the first beams circulated the Large Hadron Collider in both directions. While everyone was cheering in the LHC control room, the cheers were echoed in the ATLAS and other control rooms, and in several auditoriums around CERN.

10th September 2008