24 February 2007

Fieldwork for the Science Museum


This week I've been trying to fix a big spark chamber for the Science Museum with the precious help of Prof. Websdale. On the picture you can see him installing a scintillator on top of the chamber. I'm happy he accepted to help me because he used to build such devices in the past. I belong to the generation of particle physicist who remotely log on to a detector when it doesn't work and debug it by looking at the logfiles. In this case we use screwdrivers, a voltmeter and an oscilloscope. Something quite unusual for me...

I'm doing this because the I am LHCb-UK Outreach coordinator. As such I am supposed to coordinate the outreach activities in the UK of the LHCb experiment, i.e. explain to the average UK citizen what LHCb is doing. Since LHCb has very little manpower (to be taken as an euphemism) available for such activities there's hardly anything done. Please don't visit the public LHCb web-site, it's such a shame.

Yet as a CERN experiment we should devote part of our efforts explaining to the public what we are doing and why. CERN itself is an open laboratory with a quite decent public web-site.

What is more important in my activity as outreach coordinator is that I am part of the larger group of people who try to promote the LHC in the UK. What for? might you think, we have nothing to sell so why bother making an advertising campaign. That's the subtle difference between marketing and outreach. The UK taxpayers pay about £60M a year as a contribution to CERN and that's not counting what is paid to the research groups in the UK (my salary for instance). Some consider this as a contribution to culture: it's the price for increasing our understanding of Nature. Some might consider it as a long term investment in the future. Our economy is presently growing on the grounds laid during the first half of the past century, when quantum mechanics was developed (think of computers, mobile phones, microwave ovens, lasers...). We might be discovering now what the economy will be based on in 50 years (... or not).

In any case we owe the British public an explanation of what we do with the £1 each taxpayer spends every year to fund our research. We try to have contact with the media, we prepare material for teachers, we have set up a UK website about the LHC (here)... But we first had to find out what to tell the public. The buzzword is Big-Bang: the key message is that we are recreating the conditions of the Big-Bang in the laboratory. If you are interested in the details look at the result of the formative evaluation.

This message will also be central at the upcoming exhibition about the LHC at the Science Museum, for which I am part of the advisory panel. The exhibition will start in April and I am of course not supposed to tell you what it will show. Come and see it. There will for sure be a post here about its opening.

In order to show particles to the public the Science Museum wanted to have a "Cosmic Ray Detector" on display, a device that would show the path of cosmic rays. After some research I found out that they already had one, which Imperial College and Rutherford laboratory built for them some time ago, but that it was probably labeled "Spark Chamber" in their stores. They indeed managed to find it and now we are trying to get it operational.

Stay tuned, hopefully I'll soon be able to add another post about the successful outcome of this fieldwork.

14 February 2007

International Collaborations, Elections, and the Subtleties of Language

An election was just held to decide who would work alongside Koichiro Nishikawa of Kyoto University as the first International Co-Spokesperson for the collaboration of a couple of hundred physicists working on the T2K Experiment.

When Dave Wark, my colleague at Imperial, was nominated as a candidate, I offered him a bit of advice to help him advance his international credentials -- through the words "yoroshiku onegai shimasu" which is what Japanese politicians spew after every other sentence during election campaigns. It roughly translates to, well, er, ...according to one web page:

"I suppose every language has a number of expressions that defy translation into another language. One of the Japanese phrases that belong to this category would be 'Yoroshiku onegai shimasu.'", then going on to say:

"Thus, if I were to be forced to translate the phrase 'Yoroshiku onegai shimasu.' into English, I would say, 'I hope you will take care of ( someone / something ) in a way that is convenient for both you and me. (I count on your cooperation.)'"

Which sounds utterly shameless in this context....

My personal translation, which is what I gave Dave, was that it expresses a desire for "the concept of pursuing goodness, correctness". Beautiful.

I think he might have used the phrase at a meeting or two, though whether anyone actually understood him is unknown.

He didn't listen to my other suggestion that he ought to become the first physicist to launch a spokesperson election campaign on YouTube, however.



But now, the speculation is over. I can sense the tension in the imperialhep.blogspot.com readership.

The results were announced earlier today, and despite not having a YouTube election campaign, it turns out that Dave has been elected by a majority of the vote.

Whether our new International Co-Spokesman will ever visit us on this blog remains to be seen. Dave?

12 February 2007

Results of Paint-o-Clock


So here is the final "Paint-o-Clock" output. I think it looks rather good!

For those of you wondering, the pictures are:

  • A Segment of CMS being lowered under ground, with a muon chamber being fitted.
  • The Wilson Hall at Fermilab
  • A simulated Higgs event in CMS
  • Super-K and the T2K near detector and a cosmic ray air shower.
The sharp eyed among you may be able to spot small contributions from other experiments. The plan is to hang it on the wall of the seminar room so that we can remember the fun we had. Jamie has posted lots more pictures on his personal site.

11 February 2007

Blind Analysis


I'm a member of the MiniBooNE collaboration, and we are doing a blind analysis in our search for neutrino oscillations. The idea is that we wish to prevent biasing ourselves before we complete the analysis of the data. We are doing a "closed box" blind analysis, which means that we sequester the events that appear to be signal-like and do not perform any analyses on them before the analysis chain is complete.

Our analysis is a search for electron neutrino events in a muon neutrino beam, which is the signature of neutrino oscillations seen by the LSND experiment. We are performing the experiment to confirm or rule out the LSND neutrino oscillation result. Effectively, the blind analysis means that we use other data samples, like the muon neutrino data and cosmic muon decay electron events, to understand our event reconstruction and analysis algorithms. We do not use electron neutrino events that might come from neutrino oscillations in the development of the analysis, but only after the algorithms are complete. We are currently in the final stages of the analysis, and are hoping to open the box soon, although we have been saying that for a while!

We chose to do a blind analysis for many reasons, but one of the key reasons is that the LSND result, if it is due to oscillations, would be inconsistent with the Standard Model's prediction of only three families of neutrinos. Thus, the LSND result has huge ramifications if it is confirmed and we deemed it necessary to use the most strict methods in our search for these oscillations.

As a MiniBooNE collaborator, I am often asked if we will see a signal, which is to say: do I think the LSND signal is real? I've come to realize I don't care if we see a signal. All that matters to me is getting it right. Frankly, I think it would be scientifically irresponsible for me to hold a strong opinion about it one way or the other. I think that the beauty of science comes from the idea that Nature can reveal her secrets if we ask the right questions and are open to the answers. Approaching this analysis with a strong bias one way or the other would be tantamount to closing one's mind to a certain type of answer, and to me that would be a failure.

A lot of people in the field feel that the signal is false, and that we will rule out LSND-type oscillations, with almost religious conviction. It belies their bias in what should be an objective pursuit. I think part of it stems from the saga of the 17 keV neutrino. In that case the scientific method was vindicated (although I am sure that there was plenty of subjective chatter amongst the participants, especially at conferences) but I think the experience left a lot of people in the field uncomfortable with new and different experimental results in neutrino physics. We will shortly learn whether or not the LSND result was a false alarm, or whether Nature is a lot more complex than we thought.

And I can't wait to know the answer, whatever it might be!

08 February 2007

Cold White Matter, Cold Dark Matter

Today, London had its heaviest snowfall in years and years, though by the time I walked across Kensington Gardens, it was more slush than snow. Still, it was very pretty!


Prof Tim Sumner came downstairs from the Astrophysics group to give a seminar about the ZEPLIN III experiment, which was built on the 10th floor here, and recently transported to the Boulby Mine in Yorkshire.

It is a liquid and gaseous Xenon detector read out with photomultiplier tubes, and uses the ratio of two light signals, from scintillation and ionisation in liquid Xenon, to look for events with a signature that is characteristic of WIMPs (weakly interacting massive particles), a candidate for dark matter. It will soon start taking data, and will be probing the regions where Supersymmetric theories start predicting the existence of dark matter.

Personally, it was interesting to see the design and construction choices for their detector, having previously been in the group at Stanford building EXO, a liquid Xenon experiment looking for double beta-decay. The physics is completely different, galactic dark matter versus the nature of neutrino mass, but many of the challenges are quite similar.

Imperial Experimental Astrophysics Page

07 February 2007

Paint O'Clock!

This afternoon in 538!
Photos and the result to follow...

Jamie

05 February 2007

Interesting lectures on SUSY

The first term and a half of an HEP PhD is spent learning all of the basics needed to join a collaboration without looking like an idiot. The lectures have been winding down since Christmas, but there are still problem sheets to do...

I've been going to an interesting course taught by the theory group on Super Symmetry (SUSY), a well loved but unproven extension to the Standard Model. I'd be surprised if SUSY was actually correct, not because there is anything wrong with it, but because it just seems too easy! That said, I've been enjoying the course. It is a great refresher for some other stuff I've been learning, and made me think quiet a lot on my way home on Friday.

Anyway, enough Physics for now. It's time to go home...