[Blog post] Happy Hallowe’en!

31 10 2011

Panel 1

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[Blog post] 60ns? How about 60mn?

30 10 2011

In a couple of hour’s time the clocks go back an hour in Geneva, as European daylight savings time ends. Usually this isn’t a big deal. We adjust our watches, the nights get darker earlier, and some of us turn up an hour early for work while the rest enjoy the extra hour of rest! But what happens in the Control Room? It’s not as trivial as you’d think…

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[Blog post] The best and worst moment on shift…

26 10 2011

It’s that moment when you realize something serious and exciting has happened, but it’s 5:45am and you have to wake somebody up to sort it out. As the LHC ramps up it’s my role to make sure that the trigger is ready. This means looking at the bunch structure in the LHC and checking that ATLAS knows that this structure looks like. It’s as simple as pressing a few buttons and updating a database, and if everything goes smoothly we have nothing to worry about.

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We have beams!

We have beams!





[Article] Faster-than-light neutrino result to get extra checks

26 10 2011

(From New Scientist)

The OPERA detector (OPERA Collaboration)

The OPERA detector (OPERA Collaboration)

Neutrinos may move faster than light, but double-checking the results is decidedly slower, as the team prepares to submit a paper for publication.

Last month the OPERA collaboration at Gran Sasso, Italy, announced that neutrinos had arrived from CERN, 730 kilometres away in Switzerland, 60 nanoseconds faster than light speed. The controversial claim triggered a flood of criticism, support and speculation from the rest of the physics world.

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This is great news. There are many people out there (myself included) who are skeptical of the existing result. Unfortunately, since this wasn’t the main analysis at OPERA the experimental paradigm was not optimised for this measurement and there are a few tweaks we’d like to see to really get a precise measurement of the time of flight of the neutrinos. CERN is taking the most obvious step and they’re going to send tighter bunches, improving the precision. The new proton spills are expected to give about a dozen events which should be independent of the previous dataset, and should either confirm or refute the previous result.

What happens if the new result also shows superluminal neutrinos? Then if there is a bias it really is a subtle one and one source of bias has been eliminated. This should answer some of OPERA’s own critics. If the result shows neutrinos that respect special relativity then the situation gets a bit more interesting! The skeptics will become louder, but we’d still need more data. 15 events can’t overturn the result obtained with 15,000 events, no matter how tempting it is to dismiss the existing result. No matter what we see with these new events, we still need a completely independent check from a different experiment, perhaps MINOS or T2K.





[Blog post] Trapped on shift!

24 10 2011

There are few things more terrifying than being forced to sit for hours in front of computers and stare at plot after plot after plot. I’m pretty sure that there is a circle of hell dedicated to those people who fabricate data or tweak their datasets to try to get a controversial result. Those people are condemned to spend eternity at a desk monitoring histograms as they fly by. And their on-call experts never answer the phone. And yet the ATLAS management hail this kind of behavior as laudable and give it the grandiose title of a “shift”. They even go as far as to set quotas on how many “shifts” a person should take. Some of us are even stupid enough to sign up to them.

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The big house

The big house





[Video] Dark matter in a minute

21 10 2011

Physics in a Minute explains dark matter, in a minute!





[Blog post] Game for breakfast?

18 10 2011

Since being on night shift, my social life has become quite weird. On one of the days between shifts I woke up at about 7pm and my flatmate invited me to dinner with some friends. It was very much a last minute arrangement, and he asked me as I was about to reach for the cornflakes, still in my dressing gown. Given that they were going to one of the best restaurants in the area I decided I couldn’t say no! But instead of being served fondue, we decided to eat game, since it’s game season here at CERN! I’m not quite sure what I ate, but it was delicious, and was one of the richest breakfast’s I’ve ever had.

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Where'd CERN go?

Where'd CERN go?

This morning I was welcomed by a thick mist, obscuring my view of CERN and the Alps. On a clear day the view from the balcony is wonderful, and the mist will probably clear soon. Right now the view is of… nothing. It’s still very pretty though!