19 December 2007

Petition to reverse recent funding cuts to Nuclear Physics, Particle Physics and Astronomy

Unfortunately my first post to this blog is motivated by difficult times for physics in the UK. As you will doubtless all be aware the UK funding body covering Astronomy, Nuclear and Particle Physics (STFC) has announced severe budgetary reductions affecting each of these fields. It is feared that grants may be cut by up to 25%. This being a particle physics blog I have no doubt that the readers are aware of the specific problems this has caused for our field. However, I wanted to bring home just how many people are affected by this across the broad spectrum of UK contributions to physics, from stellar observatories to power stations. If you share the feelings of many in the community that these changes simply can't go uncontested then please consider signing our petition on the 10 Downing Street website. Hopefully, if enough people sign up, in conjunction with the letter already sent to the government on behalf of the community, we will cause those responsible to think again before they seriously damage the future prospects for physics in the UK. Thanks for your support!

12 December 2007

Exciting News from Fermilab

The new combined CDF/DZero Higgs limits were released last Friday. I would give you a URL to the results, except they haven't appeared on the Fermilab website yet.

This is because there is some even more exciting news than that. Here in the States, there is a television show called "NUMB3RS" (catchy title) about mathematicians and theoretical physicists who run around solving crimes. As a physicist who hasn't seen the show, this seems rather unlikely to me, as the last crime I solved was "who stole my orange juice?" Then again, I'm no theorist, so what would I know?

Anyway, according to 'Fermilab Today' (http://www.fnal.gov/pub/today/) a recent storyline involves one character (played by Peter MacNicol) considering leaving his exciting life of crime-fighting QFT in order to join the DZero experiment.

That's right, DZero.

The character gives his reasons for joining the experiment, hoping to discover the Higgs boson, concluding "What can be more spiritual?" I have to say, I can think of quite a few things that are more spiritual. In fact, I think I have had more spiritual moments in Bracknell - in BRACKNELL - than I have at DZero.

Don't get me wrong; the work here is rewarding, and I do see the mystery and the wonder of trying to work out why the universe is like it is. However, as the old saying goes, "The nearer the church, the further from God." Once you really get involved, you start to lose sight of the big picture; you get bogged down in all the little details. And besides, once Mr. MacNicol starts using ROOT, I can guarantee he'll feel a lot less spiritual.

Anyway, there are some fairly revealing quotes in the 'Fermilab Today' article. The first is from Darien Wood, the DZero spokesperson:

"We can always use more 'brilliant but socially awkward' physicists to help us find the Higgs"

I choose to paraphrase this as:

"We are so understaffed at DZero, we are willing to hire actors to pretend to be physicists"

Better yet is Alan Stone's reaction:

"In every episode, there is a crime. One can imagine the kind of story line they would need in order to film here (in Fermilab). There's just no possible positive spin."

To me, this seems like an oppurtunity for a great story, not a problem. Consider this: a starry-eyed theorist comes to DZero to find the Higgs. However, after a couple of weeks, he realises the frustrations due to the Object-Oriented graphics and analysis software he has to use. Eventually, he is drven mad, and flies to Switzerland to get revenge on the creator of the software. Then, the other mathematician-detectives come to CERN to investigate the grisly murder: you can just imagine the close up on the lead actor's face as he says: "Well, that's something to narrow this down... whoever did this certainly doesn't like ROOT."

04 December 2007

The Rest of Last Week

Sorry for the silence, it has been a while since I had the time to sit down and try to satisfy Patrick's cravings....




Tuesday

Get into College by 9am to do 1st Year Lab -- this is one of the 5 days this term that I have to come in so early!

These teaching labs can be as fun or as boring as the students want to make them, but I am impressed by them more often than not, and this group is exceptionally good, and right now they are discussing amongst each other about the experiment and hardly need my help.

Having said that, when asked to measure the index of refraction of a mystery liquid, one of the pairs of students tell me that they got 1.2 -- since a liquid with an index of refraction of 1.2 would be a rather special thing, I ask them what their error on that was, hoping for something like 0.1. Their answer: "we haven't done that yet!"

Over lunch, have a quick look at the previews for tonight's match. We won for the first time in ages on Saturday, and looking forward to it tonight. Our opponents are one of the few teams below us in the division, so we've got to win!

A couple of more tutorials from 2pm. The students will soon be writing an essay on a topic of their choice, so we go through some tips I have on making their writing more interesting. This may come across as profoundly ironic to readers of this blog.

From 4pm, we have our regular T2K Imperial group meeting. This time of year is fun because we usually have a few 4th year students doing their projects in our group, and we treat them as full group members, which means that they give regular reports on their progress like everyone else. Patrick and Paul are working on two separate projects, one on T2K nd280 physics and one on some detailed characteristics of some novel photosensors, and we hope that by February, they'll have answers to a some questions that we don't know yet.

You would have to ask the students themselves if they think it is just as fun for them....

Morgan and Joe are dialling in from Chicago again, which is good because it makes us feel good about being in London over the winter.

The group meetings sometimes run quite late, because they are the best forum for proper discussion (ie grillings), where we sort out misconceptions and disagreement. Today however, I was able to adjourn the meeting quite early, which gives me time to travel down to the stadium and stuff down a nice big serving of jerk pork, before seeing us come back from behind to win.

Now I think about it, this is the first time I've seen us win this season....

Wednesday

Today is one of those special days during the week when I have hardly anything scheduled except time for getting some research done. There is just one meeting, but apart from that, I have hours to get through my todo list at my leisure.

...except something unexpected crops up, and I lose a few hours doing things far removed from unravelling the mysteries of the neutrino sector of our model of the universe. I even had to excuse myself from the one meeting.

I wanted to go home early to pack my bags, or rather my single carry-on back of less than 10kg, but end up returning home at only about midnight. Which sounds fine except that I have to leave for the airport at 4am....


Thursday

This is the day of the second trip mentioned in a previous comment. The flight leaves at 7.30 from Stansted, so I get up at 3 and take the bus up to Liverpool Street Station at 4 and then the Stansted Express.

The flight is not bad at all considering I paid 6 pounds for it, and once we arrive, it only takes about a minute between going down the stairway and walking out of customs into the sun and warmth of Valencia.

The meeting is hosted by the Instituto de Fisica Corpuscular of the University of Valencia, and we immediately sit down for lunch which includes tortillas (omelettes), Iberico ham, all sorts of other yummy things, and beer. Having only slept a few hours, and being the sort of person I am, I refrain from touching the golden stuff.

I had scheduled the lunch at 11.30 so that we could have a long afternoon session, but the consequence of that was that the cafeteria had to open early specially for us, sorry!

There are about 15 people present at Valencia, and a similar number dialling in via a teleconference service, from across Europe and North America. We have to juggle the needs of everyone according to their time zones, which often can result in a total mess, but today, after some initial glitches, things go pretty smoothly. The fact that we are having arguments (constructive ones, mind you) over the conferencing system indicates that it is working well. Most of our meetings are teleconference only, but having a core face-to-face location makes things so much more productive.

This meeting is about making sure the software for the T2K nd280 detector is ready to real physics work. The software is the result of the effort of many people across the world, and encapsulates our knowledge of our experiment, so it is a big job to get it done, and to get it done right.

One of the most important items I put in the agenda was "Hot Chocolate and Churros", but for all the IFIC's hospitality, it does seem that was asking for too much!

Instead of specifying an end time for the afternoon session, I thought the best way to get the most out of the day was to continue until a Spanish person told us it was time for dinner. That duly happened at 8.30pm, so we pack up and trek across to the old town, where we indulge in loads of paella, a local speciality. I personally like Paella Valenciana, with chicken and rabbit meat, but today we are having seafood and vegetable paella. Positively yummy.

After dinner most of the group hit the bars and dives for some heroics on the town, but I, being the sort of person that I am, head straight for my hotel for a quiet night's sleep....

Friday

I get up early and walk to the tram stop well in time to make it for the start of the second day at 9.30am, but I wait and wait and no tram comes.

When one finally does arrive, I find that I am on the same tram as all the students who only went to bed just a few hours earlier, and I reschedule the start of the meeting to 10am.

Today's lunch is Paella Valenciana, so I have two platefulls. Yummy.

We continue till about 6.30pm, sorting out what we can do and can't do over the next several weeks and months. We have our work cut out for us, but it will all be worth it in the end!

This is when my week officially ends....

26 November 2007

This Week

Since there hasn't been much activity on the blog for a while, I have decided to blog about my week. I hope this will serve as a warning to my colleagues that they should update the blog reasonably frequently!

Anyway, for a detailed account of a "typical" week for a lecturer at Imperial HEP, watch this space (or avoid it, as the case may be...).



One of the founding principles of this blog was not to fill it with self-indulgent spewings, but my hand has been forced -- beware:

Sunday

Start the week in a good mood, a big chorizo omelette breakfast in the Portuguese area up the road from me.

I come in after lunchtime, a bit later than I wanted. It seems about a third of the offices down my corridor are occupied. Weekends are good because there is no teaching and fewer people come knocking on my door, although today a certain DZero physicist did come in asking to be rescued because he had locked himself out of his office....

The central event this coming week is a face-to-face meeting (as opposed to the usual teleconferences) that I have convened for the T2K experiment near detector physics software group. Today I am sending out a draft agenda for the meeting. We only have two days but a lot of work to get done, and because some people are dialling who can't travel this week from a variety of time zones, it is going to be quite difficult to arrange the sessions to suit everyone.

I also send out a reminder for some people to submit their sections of a report we are writing. Then I make a mental note to myself that I'd better get on with writing the bit that I am supposed to be responsible for.

I look through the laboratory notebooks of a dozen or so first year undergraduate students. Keeping a decent logbook of everything you do is an important part of a physicist's training, and while some are already amazingly good -- legible and detailed with lots of interesting jottings -- there are one or two where I can't figure what they were thinking. Some harsh words are in order, but then I remind myself about what I was like as a first year student, and hold back a bit....

Before catching the bus home, I continue drafting some recommendation letters that I am writing for a student. There are about 10 undergraduates that I have been tutoring who are graduating this year, so I know I'll be doing a lot of letter writing over the next several months! As far as so-called administrative tasks go, letter writing is something that I feel a sense of responsibility over -- if my wording is somehow off and the letter conveys the wrong impression, it could have a lasting effect on a person's life. One of my students graduated last year and is now studying at one of the very top Institutes in the US, diametrically opposite the one I went to (geographically), which isn't bad, although whether he actually needed any help from me to get in is another matter....


Monday

Get up early, work a bit on the report over a nice cup of tea.

Second year undergraduate tutorials at 11am, mostly about quantum mechanics. Today I am going through the postulates of QM with them, and how the physics concepts like states and measurements are linked to the mathematics, letting you calculate and predict things. In just a few months' time, they'll be able to calculate the behaviour of hydrogen atoms in laser beams and the like. In a couple of years, the lucky ones will have moved on to calculating what happens in particle interactions at a collider, or neutrino interactions with matter!

At Imperial Physics, we do tutorials in groups of about four students. I think this is about right, because for most issues that the students have, they can bounce ideas off each other and work things out on the board and come to the right conclusion, with just a bit of guidance. Any more and I think some students would find it more difficult to participate fully, any fewer and there wouldn't be the student interactions which can work so well.

Have lunch with Dave Wark at the Senior Common Room, where we are joined by a physicist from a different group. The conversation centres on the world economy, the price of CD players, and how much the space station costs.

1st year lab at 2pm. They are measuring the speed of light using a tabletop setup. My job is to wander about, saying "think about the errors, think about the errors...."

Later in the day, I receive some emails from a couple of personal tutees, asking to have chats with me. I sense some more letter writing coming my way. This week is full so I schedule sessions for next week.

In the evening, Dave, the students Ian and Francois and I attend a lecture from the IgNobel people, where some "improbable" research at Imperial are presented. It is good fun, and you can see how introducing the "quirkiest" science is a great way of showing how the scientific method works and why we all do it. The research on camel hydration and brain temperatures left a lasting impression on me.

Afterwards we end up having an extended chat with a certain prominent science journalist. Good science journalism is of course crucial for the public to understand the importance of basic research. We agree that having a good "rubbish-o-meter" is the most important thing for a journalist (although "rubbish" may not have been the exact word that was used). She also writes a lot of obituaries for scientists, and that seems to be bothering Dave somehow....

25 October 2007

Travel

I promised Yoshi in front of the entire group that I would make a post to the Blog, so true to my word, here is a first effort.
As you are no doubt aware, the possibilities to conduct a HEP experiment in the UK are nowadays rather limited. Much of the group is involved in experiments which take place overseas. Ideally we send people overseas for an extended period of time, a Long Term Attachment (LTA), which allows them to minimize the effects of travel, and maximize their ability to participate in the experiment they are working on. This arrangment works well, but for some of us it is necessary to be both here and at the experiment at the same time. In some ways this gives us the best of both worlds, but it has the nasty side effect of requiring a lot of travel.
A typical morning for me at Imperial might actually begin at 5am in Geneva. There is flight that leaves before 7am and arrives in London so that I can be at Imperial by 9am. I can say with confidence that there is absolutely no glamour in the "jet-set" lifestyle. But honestly this is a pretty easy commute. 10 years ago when we were setting up the BaBar experiment at SLAC (near San Francisco) I regularly flew between California and London, a commute which can test your endurance, and involved regular resetting of my internal time-zone.
Members of the group are currently working overseas on experiments at Fermilab (near Chicago), SLAC (near San Francisco), CERN (near Geneva), and in Japan. There are some ways in which technology has made it possible to avoid some of the travel. Participating in meetings via telephone/video/internet conference is now much more practical. There are several systems where presentations are posted to a web site, and so particpants can see all the material on their local machines, and then follow and participate in the discussions via the conference call. This works reasonably well for many working meetings, and is used by most members of the group. There are difficulties with this as well due to the spherical nature of the earth, meetings which take place in the evening in Japan are in the morning here, meetings in the evening here are in the morning in California, and so there is actually a rather small window of "working hours" where these conferences can take place without causing one side or another to come in very early, or stay very late. Some times, however, it is just necessary to travel. It isn't yet possible to plug in cables on the telephone, and sometimes you just need to be in the same room as your colleagues or your detector to work through a problem.
I've picked out some of the difficulties of the travel, but it also comes with a lot of benefits. As well as getting to work in some very nice places, one gets the opportunity to work with colleagues from around the world. These interactions are extremely valuable in broadening our work methods and our ways of approaching various problems.
That's it for now, I've got a plane to catch...

14 October 2007

Starting Out


It's the start of a new academic year and, for me, it's back in from the cold of the "real world". After 4 years working as a Market Analyst I'm having a great time settling in to a new life as a Postgraduate Student in the Imperial College HEP group. I dare not whisper "PhD Student" yet, as we have to get past year 1 first...

I'm one of 12 new students this year, which is apparently the highest number since 197_. We're an interesting mix of people, with a half-dozen countries represented. In the first term the focus for us is on study, which is especially useful for someone like me who's undergraduate notes are already browning with age. We have started a handful of courses so far, taught by members of the HEP group, and are also free to attend any interesting undergraduate courses; which most of us have been taking advantage of, when our schedules allow.

By the end of November, we're expecting to have been assigned to the projects that will take us through the full 4 years. There’s been a lot of discussion among us students already and a bit of early bribery from some of the staff – thank you for the beers all of you. We’re expecting some more formal presentations over the next few weeks and then we should have a better idea about who we should be buying the beers for.

Because there are so many of us this year, we're not all in the same office but being kept more-or-less together has been a great way to form some promising friendships already. I'd like to invite any of them who reads this to add a comment so we can hopefully give anyone thinking of starting here next year a good idea about what to expect.

13 October 2007

How fit is your collaboration?

Social events are an important part of about any scientific conference. Some argue they are even the most important part of the programme as they allow people to get together and discuss in a more relaxed atmosphere than the three minutes question time after the talks. Usually one half-day is reserved for some kind of excursion.

It was no different at the LHCb collaboration week in Saint Nectaire a month ago. On Wednesday afternoon we could choose between (a) a guided tour of six roman churches, (b) a guided visit of a volcano, or (c) climb the Puy-the-Dôme. From the 200 participants, 130 chose option (c), a 500 m climb of the landmark mountain next to Clermont-Ferrand. The organizers counted 3h30 for the hike and told us to hurry up if we didn't want to miss the bus. Actually everybody had reached the summit in much less than two hours. Some of us even made a detour to climb the Puy de Pariou, a small volcano with a nice crater (straight under the blue paraglider on the picture above). We were all quite impressed by how fit the collaboration is! Nobody expected that so many people would choose to climb a mountain between two meetings.

We also elected a new spokesman for the LHCb experiment. After more than 10 years in charge of the design and construction of the LHCb experiment, Tatsuya Nakada will step down as spokesman next year. The new spokesman-elect is Andrey Golutvin, director of ITEP Moscow and co-convener with Ulrik of the rare decays working group. A new era is starting, with a new spokesman and hopefully real data very soon.

08 October 2007

HEP vs SPAT football match


It was billed as the battle to see who held sway over football bragging rights in the Physics department. HEP vs. SPAT. There were many volunteers on both sides. The mouth watering clash was six weeks in the making and took place on Thursday last week - 04/10/07...or should have. Thanks to Murphy's law it did not. The SPAT footballing maestros couldn't put their money where their mouth was and pulled out at the worst possible time - the morning of the match. Apparently, a sweeping bout of freshers flu was to blame! Turning disappointment into action, HEP (Ajit, Aaron, Onuora, Tom) decided to go ahead and play. Fortunately, Deltadot (Wen, Mark, Gary, Dave, Reese) was at hand to oblige.



The match, which took place at Hyde Park, ended 7-5 in favour of Deltadot. It was evenly balanced for the first fifteen minutes as both sides probed for an opening. Deltadot finally made the extra-man count to get on the score sheet. The game was evenly poised at 2-1 in favour of Deltadot with both sides missing a few gilt-edged chances. At 7-4 they seemed to be running away with it but HEP pegged them back with uncompromising defence and a goal at the death.

Good job lads!

27 August 2007

T2K Horn Testing


I've been in Japan for the the past week, working on horn tests for T2K's third neutrino horn at KEK (pictured at right). The horns are devices that create strong magnetic fields which are used to focus charged pions into a long decay region where they, not surprisingly, decay into neutrinos. T2K will employ three horns in series to create the world's most powerful neutrino beam. Each horn itself is essentially two concentric aluminium [sic] cylinders which carry
a high electric current. Between the two cylinders, a powerful magnetic field is created and that bends the paths of any charged particles passing through.

The horns must generate strong magnetic fields but they run in a high radiation environment so they must be very robust. The T2K horns will operate with an electric current of 320 kA. For this much current, the power is distributed along large aluminium striplines (pictured below) which feed the horns.



The work this week was mainly to test the structural stability of the newly constructed third horn. The first horn was tested extensively earlier this year. The currents and fields created by the horns are so strong that they exert tremendous mechanical stresses on the devices and must be tested extensively before being deployed in their final locations in the beamline. The mechanical forces are so strong that the horns emit an incredibly loud bang each time they are pulsed; it sounds as if someone were banging them with a sledgehammer. Given the amount of energy being pulsed through the horns when they operate, that's not a bad analogy.

The tests themselves are simple enough: we just run the horns in the same way that we will in the experiment. The horn experts spent the past few weeks preparing for the tests by setting up the DAQ and monitoring tools so that non-experts (like me) could come in and watch to make sure nothing went wrong. The plan was to test the horns for 10.5 hours per day in three shifts of 3.5 hours each. We didn't test the horn overnight because the noise is so loud you can hear it off-site, and it's important to keep good relations with the community surrounding the lab. The only hitch has been the extreme heat that Japan has been experiencing this summer. The building where the horns were tested does not have air conditioning, and if the temperature inside went over 37 C we halted operation until it went back down below that threshold. We lost three afternoons to the heat last week! Nevertheless it was a successful week: the horns were pulsed over 44,000 times last week while I was there.

14 August 2007

Ask me... I'm an expert

Remember the posts about the Big Bang exhibition at the Science Museum? Well, if you haven't seen it yet hurry up. It's on until the 7th of October, after which it will be replaced by [not allowed to tell ;-) ].

To add a little more action to the displays the Science Museum set up a little interactive event last week where they would show some kit and have a couple of scientists explaining it. The plan was to have a cosmic ray detector and some Geiger counters. We provided the latter but they were quite useless in the end as nobody was able to bring anything even remotely radioactive to make them tick. So we concentrated on cosmic rays, which was not a bad idea anyway. Our colleagues from Bristol provided a scintillator and a small spark chamber, definitively the star of the show. It's much smaller than the huge one Imperial and RAL built long ago and we could not get to work again. At least the Bristol chamber worked nicely. Don't know if there's a lesson here...

It was a lot of fun explaining cosmic muons to the general public (although the general public found at the Science Museum is a quite biased sample) and answering the most unexpected questions. How do we know they are muons? Where do the cosmic rays come from? How does it work? Could they have triggered life? What's this black thing? (the trigger). Wouldn't the muons have all decayed before reaching the ground? (This guy knew more than expected). How do you get a satellite on orbit? Hmmm, somewhat unrelated, but I had a tag saying "asking me... I'm an expert" so I just had to know.

Many thanks to the Bristol guys David, Clare, Ben and John for providing the nice kit and to Will and Tom for representing Imperial.

Finally I agree with Gavin: we should try to build a similar chamber and display it on level 5.

29 July 2007

A Week in the North of England

We just got back from the biennial High Energy Physics conference held by the European Physical Society, this year in "The North of England, at Manchester".
The poster for the conference was a nice Lowryesque image of the city, with matchstick physicists heading for the brand new Bridgewater Hall, where the main sessions were held.

As usual with conferences, the days were filled with rather intense schedules of parallel and plenary talks, while most evenings were kept aside for social events, where attendees discuss the day's talks with their colleagues and new people they have met, and which are usually accompanied by refreshments to help the discussions along (including the Beer Tasting that was organised by Lee Thompson of Sheffield, which I certainly appreciated).

Most of these social events involved Dave Wark, our colleague on T2K at Imperial, in his role as the chair of High Energy Physics at the EPS, standing up and trying to tell jokes in a room seemingly chosen such that no one was able to hear him. The first of these was at the very impressive Manchester Town Hall, where it was clear to see (but not hear) that the Lord Mayor was enjoying Dave's speech very much indeed. I later learnt that he was rattling off the names of physicists from Manchester who had made Nobel Prize-winning contributions to our field. This list included the likes of Rutherford, Chadwick, Blackett, Bethe and several more, which is actually quite amazing.

The Lake, LS LowryOn the Sunday off, Dave and I checked out "The Lowry" gallery, where many of LS Lowry's works are on display, along with artefacts from life in the Industrial North, with contrasting images expressed mainly through paintings, photographs, Coronation Street (the TV soap for our international readership), and Labour Party pamphlets. It is a great day out and puts Manchester as we see it now in proper perspective. It was curious to note, however, that the conference poster was for some reason not based on Lowry's Manchester as depicted in paintings such as "The Lake".

Coming out of "The Lowry", one is confronted by "The Lowry Outlet Mall". Perhaps celebrating Manchester's place as the centre of consumer culture in the North would have pleased the artist. Then again perhaps not.

One of the centrepieces of this conference is the presentation of the EPS Prizes. This year the main prize went to Makoto Kobayashi and Toshihide Maskawa, of "Kobayashi-Maskawa Theory" fame, and the K and M in the "CKM Matrix", the "C" being Nicola Cabibbo. Their paper in 1973 showed that symmetry violations that had been seen in nature, but difficult to incorporate into the understanding of physics at the time, could be described if 6 quarks existed, which were linked together through a 3 by 3 component matrix. This was at a time when the existence of quarks themselves, and whether there were 3 or 4, was a point of contention (though I would like to state that was quite a bit before my time!).

I'll leave it to our colleagues on BaBar and LHCb and DZero to remind the world of the significance of that particular Matrix....

Kobayashi was able to make it here and gave a presentation in acceptance of the prize. Although both K & M were at Kyoto University when they wrote their seminal paper, he clearly wanted to demonstrate that the work was a result of the Nagoya tradition of theoretical and experimental physics, just like the earlier MNS (Maki-Nakagawa-Sakata) matrix that we have been probing in our neutrino experiments.

Later in the week I bumped into one of my 4th year project supervisors at Kyoto, Prof Masaike, who I hadn't seen for, well, shall we just say a very very long time. He is close to Prof Maskawa (whose Quantum Field Theory course I remember sitting in), and over a pint of some nice dark Mild, he let me know that not only was Maskawa unable to make it to this particular conference, but he has actually never left the country ever in his life. Perhaps it will take even more than the EPS prize to persuade him to travel outside of Japan....

14 July 2007

What you missed at the Staff Party

Wednesday all Imperial Staff were invited to the Centenary Staff Party, basically a big garden party on Queen's and Prince's Lawns. If you didn't attend, here's what you missed:

  • All shop and restaurant staff dressed in Edwardian style.
  • A chance to see the inside of the giant marquee on Queen's lawn. Rumors that it's the largest marquee in the world are definitively wrong. It's not even the largest in the borough, as some websites claim the world's largest marquee was used at the Chelsea Garden show.
  • The Fab Beatles, a Beatles cover band specialised in the early years up to and including Help! but without Yesterday. I learned that to make a good Beatles cover band you need four guys including one left-handed, one who can play the guitar, one who hardly can play drums and one wearing glasses, all of them with the appropriate hairdo. The latter John-guy didn't follow the rule and had anachronistic long hair. But he was clearly the best approximation among the four.
  • Fake That, another tribute band. Honestly, I couldn't really judge how good they are as I don't really know what they are supposed to be faking... Ask Yoshi, he seemed to be much more knowledgeable. There's a picture of the band above, but my autofocus seemed more interested by the balloon in front of the stage.
  • And of course, the rector's dance. Luckily youtube saved it for the posterity.

Overall it was a nice party. College should make it annual! I don't want to wait 100 years for the next one!

13 July 2007

Royal Visit


I had a unique experience for an American this week: seeing the Queen in person. She visited the College as part of the Centenary events, and had a quite a busy day from what I've read---but I guess that's always the case when she visits someplace. In the picture I've posted, she is walking through Upper Dalby Court here in the South Ken campus with the Rector, Sir Richard Sykes, having just dedicated the new Biomedical Engineering Institute and on her way to congratulate the College on 100 years of greatness. I was one of the "well wishers" who gathered to greet her en route. I'll confess that it was fun because I have always been a fan of pomp and circumstance, but I was disappointed that she didn't have time to chat because I had honed my elevator pitch about experimental particle physics and was quite prepared to make her love our field. Another time, perhaps.

27 June 2007

To What End?

Hello everyone, I've been thinking about what to post and looking at all the blog entries in the Imperial College HEP blog spot, it is obvious that the majority deal directly with the various HEP experiments carried out here at Imperial or with the HEP group itself. So I've decided to go the other direction - write on stuff that is indirectly related to HEP.

Of the long list of questions that I find interesting to mull over every now and again, I guess one of the more important ones would be my desire to understand the role of HEP in contributing to the well-being of society. Think about it; of what use is HEP to the day-to-day dynamics of society. When I leave the office and am out with my friends how does HEP contribute to my life? If I'm out shopping, sightseeing maybe, how does HEP contribute? Or if I'm simply spending time with family how does HEP contribute to how I interact with them? Another way to look at it would be to ask: how does HEP contribute to my understanding of myself as an independent entity with a role in society?

These questions are not asking about the opportunities that arise from working in a HEP environment such as travelling, attending conferences and the like. They are asking about the intrinsic purpose of HEP with respect to humanity's existence in the sea of creation. To answer, perhaps a good starting point would be to take a step back and try to figure out why HEP and indeed all institutions of knowledge became necessary in the first place.

The first important clue is that every human endeavour, be it Science, Technology, The Arts, Economics or Religion has as its original goal the desire to study and understand the human being, the environment or the interaction between the two, where the environment in this case refers to all physical creation that is separate from the human being, i.e. the earth, the universe, and so on.

The second clue is that a system, any natural system, will be composed of elements that are each unique. The uniqueness of each element automatically generates the property of diversity within the system. In a system that is composed of sentient, self-aware elements, for example human beings, this leads to the phenomena of demand under which each element recognizes its deficiencies relative to the strengths of the other elements within the system and reacts to this by striving to address the balance.

The third clue is that the act of striving is a natural action that is induced and controlled by the principle of evolution that permeates all creation.

And so combining clues 1, 2 and 3, we are left with the conclusion that HEP and indeed any other human endeavour exists for no other reason than to serve the phenomena of demand which is itself a natural attribute that is inherent within any system in creation. This is a sweeping statement. And it is one that raises a lot questions foremost of which are: What is demand? What is evolution? How are they defined and what are their origins? The answers to these questions become of even greater importance in the face of the realisation that there is still much that is unknown by the various institutions of knowledge in their attempts to plumb the depths of the mysteries of man and the environment. Society today is a paradox. It is the epitome of good health - evidenced by the immense technological progress over the last couple of decades, the space age, ground breaking discoveries, etc and yet it appears on the brink of imploding - evidenced by poverty, war and consumerism. How did it all go wrong?

The list of questions can be endless, but inevitably they are all tied in to a common theme - the origin, purpose and future of the human being in the cosmos. As it is today, humanity finds herself in real danger of completely missing the big picture as she concentrates on moving further and further down the path of the individual disciplines in search of the Holy Grail. What should be done to correct this imbalance?

I'll stop at this point and open the floor to comments. I must point out that this blog is somewhat of a teaser. All the questions have answers, no surprise there! However, the point of this blog is to emphasise the fact that HEP and indeed any other discipline in any of the institutions of knowledge exists only to serve demand. And so perhaps the key for maximizing the potential of HEP would depend on understanding fully what demand entails.

22 June 2007

The Bubble Chamber Football Tournament (including results)

This year's Bubble Chamber Football Tournament is on Saturday 23 June, at UCL's training grounds somewhere in North London.

The tournament was inaugurated decades ago by university groups in the UK who worked with Bubble Chambers, the main tool used in particle physics experimentation in the '60s and '70s, which provided the most stunning images of particle interactions.


The participants are, allegedly:

UCL x2
Bristol
Imperial
Manchester
Birmingham
Cambridge
Exiles?
Misfits?

You could say it is a bit like the Ivy League, except it is proper football and Bubble Chambers are a lot cooler than Ivy.

Neither of the two American universities that I have been associated with in the past, MIT and Stanford, are in the Ivy League, and definitely had a long history of working with Bubble Chambers.

I am sure that if they would like to send some teams over to the UK next year, they would be welcome to join the Bubble Chamber group of universities!

The Imperial team has been practising for the last few months, every week on Wednesdays. I can't say much more here, because our formation and free kick strategies are top secret, but I'll just say that with his dazzling white boots, smart kit, and incredible pace, you might have thought that Wayne Andrews was playing for us on the wing. Just don't tell the other teams that he (our winger, I mean) is a donkey!



The Imperial College High Energy Physics Football Team


Saturday was a great day out, with all the teams arriving more-or-less on time and the weather holding out till just before the final kick of the afternoon.

We started out losing 1-0 to Bristol in the first match of the group stage, but since this was the first time the Imperial team had actually played together ("practice sessions" notwithstanding), we weren't too disappointed. The Bristol players had clearly met the rest of their team before Saturday.

The highlight of the day was the Central London Derby, our second match, which ended
Imperial College London 6 - 0 UCL

Personally, I think it was my tight man-marking of their right winger (and goalie) "J.B." which ensured our clean sheet.

We then went on to beat Manchester 2 - 0, and at the end of group stage the table ended up like this:

Pts GD
Imperial 6 +7
Bristol 6 +2
Manchester 6 +1
UCL 0 -10

After this some more matches were played, Birmingham won, and Cambridge (not UCL) got the wooden spoon, known (for purely historical reasons as far as I could tell) The Troll.

Next year's tournament will be at Manchester, to which there are cheap direct flights from Boston....

11 June 2007

SciBooNE or: How I learned to stop worrying and love the MRD


After many months of cajoling, I feel that I should write a blog entry on what I have been doing whilst living out here in the USA other than enjoying their fine beers, moderately sized meals and small economic vehicles.

I suppose I should first explain how I came to work on SciBooNE in the first place. In January 2006 I joined the T2K group my supervisor, Morgan Wascko, a new lecturer joining the group. As it turned out Morgan was also co-spokesperson on the SciBooNE experiment which at that stage was a proposed experiment to be built out at Fermilab to measure sub-GeV neutrino cross-sections of interest to T2K. After some discussion it was decided that this would be a good opportunity for me to get some hardware experience by going out to Fermilab and helping in the construction of one particular element of the detector, namely the Muon Range Detector (MRD).

The MRD is an iron-scintillator sandwich detector consisting of 13 alternating horizontal and vertical layers of counters separated by 5cm of iron. The total depth of iron in the detector is 60cm which corresponds to stopping a 900MeV muon. The purpose of the MRD is to measure the energies of muons produced in neutrino interactions, for example charged current quasi-elastic (CCQE), where a muon and a proton (muon neutrino) or neutron (muon anti-neutrino) are produced. By measuring the muon energy the neutrino energy can be reconstructed.

In May 2006 I visited Fermilab for 1 month to construct and test the prototype counter design for the MRD. By June the design had been approved and mass counter assembly could begin.
I returned to Fermilab in July this time to assist in the full counter assembly which got underway at the beginning of that month. With 362 counters to be made and 3 days needed for each counter to be produced this would be the largest single job for the MRD construction. The final counters were finished in December just in time to begin the detector assembly in January. At this stage it was decided that I should move to the States to help complete the detector construction and to see it through the beginnings of its data run.

The MRD is a unique detector in the fact that it is almost completely constructed from previously used materials. The scintillator panels (20cm x 155cm x 0.6cm) were taken from an earlier Fermilab experiment whilst 5 different photomultiplier tube (PMT) flavours are used to readout these counters. The iron having enjoyed a number of years outside in the elements had to be cleaned before it was ready to be used. Even some of the cables, both high voltage and signal, had been previously used. When it came to inspect these cables, in storage in a disused detector hall, they were found in a mess, you could say a ratsnest, not so much because the cables were tangled but rather a ratsnest! As 2 grad-students went about untangling the cables two 'rats' (though they could have been large mice) emerged from their makeshift home. Needless to say this added considerable time to the cable inpections as every inch had to be checked for damage and a number were rejected having been partially chewed!
The PMTs have a range of ages, from relatively new tubes used in the KTeV and NuTeV experiments, to RCA tubes that date to the early 70's and no doubt have been used in a number of different experiments over the years. As you can imagine this produces particular problems when it comes to understanding your detector efficiencies. It is a credit to all those involved in the construction that when the detector was switched on in May 2007 only 3 of the 362 channels were found to be dead, well below our expectations.

In January the detector construction got underway in Lab F on the Fermilab site. At this stage SciBooNE, a supposedly small experiment, was starting to sprawl. Office spaces could be found in Wilson Hall, the CDF trailer and the main CDF building. As for the detector construction, the CDF pit was devoted to SciBar and the EC whilst the MRD had spaces at Lab F and Lab 6 not to mention cable repairs taking place at the D0 hall and the civil construction of the SciBooNE hall in the Booster neutrino beamline. SciBooNE was maturing fast and with the aggressive schedule put forward the hope was to see a completed detector by early June in time to commission before the proposed shutdown in August.

The MRD construction proved to be a challenge. Initially the first few planes proved trivial to construct. However as more and more planes were added to the frame so the space between planes diminished. By the time the detector was completed the space between planes was 30cm (the depth of a fermilab standard issue hardhat!) Unfortunately by this stage the american portions had got the better of myself and Nakaji (nickname: 'The Blackhole') and so it was to the smallest of our collaborators, Kendall Mahn (5' 2") to complete the work. We looked on eating doughnuts (raspberry cream I believe).

The detector construction was completed in March and was partially cabled allowing us to test the DAQ system with one week of cosmic data. The move date was set for 23rd April, and so it was apt that "Once more into the breech" was mentioned more than once that day as a 360 ton crane lowered, i've been told i'm not allowed to say dropped, the MRD into place. SciBar and the EC were lowered 2 days later.

At this stage a number of tasks in the detector hall had to be undertaken and it was hoped that the MRD cabling would begin around the 25th May and be completed by early June. However with NuInt, a neutrino interactions conference, to be held at Fermilab from 30th May until 3rd June it was with a last gasp of energy that we pushed to complete the cabling early so as to show beam events at the conference. As you can see from Morgans post we succeeded in doing so but I think it is an astonishing feat that we completed the cabling of the detector on the 24th May, 1 day before we were meant to start!

I hope this has given you a little insight into SciBooNE and the MRD, I personally feel that it is astonishing that such detectors, both SciBar/EC and the MRD, can be constructed in such a short space of time. In a little more than a year a detector went from merely a blueprint with a counter design that had yet to be confirmed as suitable, to a detector taking data. SciBars timeline is equally incredible given that it was shipped in from Japan and had to be reconstructed with a new support frame and DAQ system. It has been a great experience to work in such a dynamic collaboration, I hope this continues. All SciBooNE collaborators must be congratulated for all their hard work.

P.S. I am in the process of making a website where I will be posting photos of the MRD construction among other things T2K/SciBooNE related. I will post a link in due course.

08 June 2007

First Neutrinos in SciBooNE

I am the co-spokesperson of SciBooNE, Fermilab's newest neutrino experiment. We have a small detector with fine-grained tracking capability (for a neutrino experiment) placed 100m from the beam target of the Booster Neutrtino Beam, which is the same beam that sends neutrinos to MiniBooNE. We've just crossed the latest and most exciting of a series of significant milestones: recording our first neutrino events! Early last week, our Run Coordinator Masashi Yokoyama from Kyoto University, led the SciBooNE graduate students on an all-nighter so we could record a neutrino event or two in time for the NuInt07 conference at Fermilab. The results were fantastic, and one example is shown at right.

The picture is a top-view event display of our first neutrino interaction with energy deposited in all three detector subsystems. The green field at left represents the SciBar detector, which is made of plastic scintillators with wavelength shifting fibers read out by multi-anode PMTS. The traced square and rectangles in the middle represent the Electron Catcher (EC), which is a lead/scintillating fibre EM calorimeter. The beige strips with small green trim at right represent the Muon Range Detector, which is made of 5 cm iron planes interspersed with plastic scintillators paddles read out by 2-inch PMTs. Maybe Joe will write a blog entry to describe what the MRD does; he knows all about it since he built it! Anyway, the event appears to be a single mu+ track from a muon-antineutrino. In the display, the red dots in SciBar represent strips that registered PMT hits, and the size of the dot is proportional to the amount of charge recorded. The horizontal blue and red lines next to the EC show the amount of charge read out by the EC PMTs (the EC modules are read out on both sides) and are consistent with a MIP. The MRD squares represent scintillators that were hit; we can see that the muon penetrated at least 7 of the iron planes.

Although we have identical readout systems for the side view, we were not running those channels when this event was recorded because the cooling systems were not yet fully operational. They are operational now, and we should be ready for stable beam operations by early next week.

It's a very exciting time for SciBooNE!

21 May 2007

R-ECFA Meeting 11-12th May

ECFA stands for European Committee for Future Accelerators. The committee visits institutes in its member countries to assess the current status of accelerator physics and make suggestions on how things can be improved. I was invited to give a talk at a recent Restricted-ECFA meeting that was held at Imperial. They wanted to get an idea about what PhDs in particle physics are really like, so gave a talk about what I had done during my PhD, why I did one in the first place and what my future plans are. It was a lot of fun to stand up and give a talk that was all based on opinion (so I couldn’t technically get anything wrong!). I told them that I thought the atmosphere at CERN was great and that everyone who works there is really enthusiastic. I also said I thought the funding for PhD students was set a quite a reasonable level, sorry to anyone who thinks I should have used the opportunity to campaign for more cash. I had a few complaints, mainly about PPARC admin department (all PhD students have a story or two to back this up) and GSEPS (transferable skills courses) which are generally a waste of time. In the main I think I am lucky to be working in such an interesting and diverse field, especially at such an important time, so that’s what I told them.

Many people gave talks concerning the state of physics in schools, funding for research and general overviews of experiments and institutes. The committee returned a very positive verdict about the status of physics in the UK and made some constructive suggestions. They commented on the small proportion of women in the field but accepted that redressing this balance is a complicated, long term process.

14 May 2007

Rector supports blog


Last Friday Imperial's rector Sir Richard Sykes visited CERN - in particular the two experiments with IC involvement CMS and LHCb.

The visit was supervised by CERN's VIP service, a guarantee that nothing can go wrong: 9:00 pick up at the hotel, 9:25 arrive at LHCb, visit. 9:45 go to CMS, photographer is waiting... and so on until the signature of the guest book at 14:15 (involving another photographer). A quite impressive organization that has not much in common with the usual "private" visits of LHCb or CMS.

So early in the morning Jim and the rector met us (Tatsuya, our spokesman, Will and myself) at point 8 for a visit of the LHCb detector. Tatsuya showed every interesting detail and let us enter any usually forbidden door. A quite interesting tour, even for LHCb members!

Of course we had a long stop in front of RICH1 where I tried to explain how it works (remember Cherenkov radiation?) and why we need such a device and CMS don't. I also took the opportunity to ask him if I could make a picture for the blog. That's when he said it was a great idea. One needs to be modern...

After a brief visit of the LHC tunnel we left Tatsuya and Will and continued to point 5 for a CMS visit. Since I hadn't seen CMS for quite some time (especially not since there's something in the cavern) I joined the CMS tour - which was really impressive. Not only because of CMS, but mostly because Jim knows every detail of it and seems to remember an anecdote about every piece of equipment. He also seems to remember each price tag...

The morning was quite challenging - the rector - a biologist - had many interesting questions and seemed very interested about the goals of the research and the technical challenges. I am also not used to being followed by a professional photographer all the time!

We then went to CERN for a lunch with Lyn Evans - head of the LHC project - and Geoff (who would later show the CMS tracker). Of course I tried to get a few insider information about when the LHC will start, but the official statement remains: there will be an announcement by the end of the month. (But feel free to drop by my office I you want to hear some unofficial statements).

01 May 2007

Must See TV Tonight

Apologies to our vast international readership who do not have the privilege of paying the BBC licence fee, but tonight there will be a programme on BBC2 at 9pm, called, ahem, Horizon: The Six-Billion Dollar Experiment.

Yes, it is about the LHC.

Since there is absolutely nothing else on the telly tonight, I am sure the whole nation will be captivated by this programme.

Among the questions to be answered tonight:


  • Will the BBC get the physics right?
  • Might the LHC create a black hole which will gobble up the planet (a question that I was asked at passport control last month!)
  • Will anyone tell them that "the God Particle" is a really really useless name for the Higgs? (with all due respect)
  • Will any of our colleagues at Imperial HEP appear?
  • How will Peter Crouch do against John Terry and Michael Essien?

15 April 2007

The IOP conference

This years IOP conference took place from the 3-5 April at the University of Surrey . For anyone who's not familiar with the conference it's aimed at getting all the final year students to give a conference talk before the end of their PhDs. It's also a very good excuse to get the students and lots of the staff from all the groups over the country together for a few (!) drinks.

Somehow, and I'm still not sure how, I managed to end up responsible for everyones paperwork. For any current second year students out there I'd avoid this at all costs! It took 24 forms, one lost cheque and a lot of chasing but finally we were registered.

The week before the IOP conference we're expected to give a practice run in front of the group at Imperial. I think it's fair to say that whilst this was incredibly useful it was also totally disheartening, probably for the staff as well after 7 hours! The most important lesson for me seemed to be that as I'd gotten used to giving collaboration talks I'd also picked up some really bad habits. The biggest criticsims, providing far too much information on the slides and my use of complete scentences.

The real thing, strangely, was a lot less scary (even in the main lecture theatre) and despite all my complaints beforehand about ending up in a session with mainly ZEUS students, I actually really enjoyed it. In fact the talks I enjoyed most were nearly always from the running experiments. I guess it's good to see something other than MC studies for once. The downside was that everyone was there for these talks and few people showed interest in the two LHCb talks tagged on at the end.

It was really good to catch up with everyone else in my year and I've probably learnt a fair bit from all the talks but I'm glad it all only happens once!

12 April 2007

Bye Bye Imperial College

Friends and family are sometimes amazed when I describe how the career path in particle physics works. I think this is quite an interesting subject and also different than many other careers, so I thought I would create a post on this. This is particularly relevant as I have just changed jobs. So for this one time we will not talk about physics but instead about what it is like to do physics.

Particle physics is a very international field. For example I grew up in Amsterdam, the Netherlands, where I also did my undergraduate studies. When I graduated I decided continue study for my Ph.D. in Amsterdam, at NIKHEF. About half of my five-year Ph.D. I spent in Chicago, working at Fermilab. Once I received my Ph.D. I accepted a contract for two years at Imperial College, as a research associate. Young researchers that are not lecturers or readers yet are usually referred to as Post-docs. This has to do with the fact that they already have their doctorate. I recently accepted a more advanced post-doc position with Cornell University. Even though Cornell University is based in Ithaca, New York, USA, I actually will live and work in Geneva, at CERN. The next step in my career probably would be to become a member of staff at some university. I am very much looking forward to that, as it would involve teaching and working with students.

One of the interesting things is that during all this time I was working in large international collaborations, so there really is not much difference except for the location and your direct colleagues. I think that if you ask a random particle physicist they will tell you that their work is so international that location really does not make a difference any more. I now have just started a new job and besides having moved to a different country the only change I've noticed is that being closer to the detector project I work on makes life much easier. Oh and the fact that the weather is better in Geneva, of course!

I love my job and the traveling is one of the additional advantages (besides doing something fun, interesting, challenging, with motivated colleagues in an international environment)

11 April 2007

Opened Box


Well, the big moment is about to arrive. More than a decade ago, the LSND collaboration shook up the particle physics world by announcing a neutrino (actually, antineutrino) oscillation result whose interpretation requires physics beyond the standard model. As I wrote in a previous entry, I am on MiniBooNE which has been working on a blind analysis to confirm or refute the LSND result for the past ten years. We have been pushing very hard to "open the box" and see what the answer is for quite a while and it has finally happened.

Our box opening procedure was a four step process in which each step was designed to reveal enough information that we could decide if things were working correctly, but not enough information to tell us the answer. Thus blindness was preserved until the final step. Our procedure was designed so that if a problem were to be found in one of the early steps, we could stop the procedure and try to fix the problem, before starting over again. Doing that would be OK as long as we did not reveal any information about the contents of the box.

Today at Fermilab, our first oscillation result will finally be announced, and tomorrow I will give a seminar on the result myself here at Imperial. I can't say what the answer is yet, so you'll have to come to my seminar to find out!

As an interesting side note, we did have to stop the box opening procedure and start over again, so it was a very good thing that we had this procedure. We attempted a box opening in February, over the weekend when I wrote my blind analysis blog entry, and discovered a reason to abort the process and regroup. But a full entry about that will have to wait until the result is announced to the world. Right now, I have to complete my seminar!

08 April 2007

Big Bang exhibition at the Science Museum

Some time ago I wrote about Fieldwork for the Science Museum and promised some updates. Back in February we were trying to repair an old spark chamber for an exhibition about the LHC at the Science Museum. The exhibition is now open but the spark chamber isn't there.

Dave spent a lot of time trying to repair the spark chamber and there is still a hope that it will go to the Science Museum. But it missed the deadline for the exhibition opening. The problem was with the trigger. The chamber is activated by two huge scintillators which produce a signal when a charged particle crosses. One is mounted below the chamber, the other is on top of it (it's the kind of gnu horns you can see on the picture in the original post). All the light guides (that guide the scintillation light to the photomultipliers) are broken. They can be repaired but that takes some time. Dave is working on that. As for the chamber itself, it looks OK. It produces nice sparks when activated by an almost random trigger.


The exhibition is essentially a huge cube of 5m size explaining in four zones what the LHC is about, how it works, how the detectors work and how the data will be analyzed. Or, well, as the exhibition is aimed at 14 to 17 year olds, it does not explain that much but gets a feel for how complicated and huge it is. The exhibition is actually called Big Bang (and that's what you'd read from the distance), as it's about recreating the conditions of the Big Bang in a laboratory. The illustrator made a great job drawing particles and collisions. I love his drawing of a cavern with all the ongoing activity! I won't say more. Come to the Science Museum (it's free) and see it.

The whole design process started (for me) in December where I attended a day long brainstorming session with 20 more physicists from various places in the UK. The team from the Science Museum was quite impressive at extracting as much information and ideas from us as they could. Of course many of them were not feasible, like putting a 1:1 picture of Atlas on the wall (rejected as it wouldn't fit: the museum is much too small!) or putting a real Grid node in the museum. Instead there's a lot of graphics, animations and small movies.

Then for several months we got spammed by the designer teams sending us text snippets to check for scientific accuracy. A month ago there was a meeting with the designer who explained us his ideas for the layout. Scientists and designers: two worlds collide... But we eventually managed to speak a common language.


Three weeks ago I got a mail asking if I was happy to be quoted in the exhibition saying "These high-energy collisions will replicate the conditions that occurred in the moments after the Big Bang, 13 billion years ago". I don't remember having ever said that and would have said 14 anyway... They obviously got a lot of quotes from the brainstorming session and wanted to match them with real scientists. So I agreed provided they change the age of the Universe (!). The result is shown in the picture.

01 April 2007

The National Particle Physics Masterclass

Last Wednesday we organised our traditional annual masterclass (see web-page). Practically this means we invite 120 A-level students having chosen physics as one of their main subjects (and therefore hopefully interested) and talk about particle physics during an afternoon.

We had four lectures about antimatter (Patrick), Higgs searches (Gavin), neutrino oscillations (Yoshi) and solar neutrinos (Dave) and a discussion session where students could ask a lot of questions ranging from "Why do you like particle physics?" to "Can you explain Bell inequalities in 5 minutes?". If there's any question still unanswered don't hesitate to post it on this blog using the "Read/Add comments" link below.

The masterclass went quite smoothly, given that the air-conditioning decided to die during the morning, which forced us to reshuffle the order of the breaks a little. There's no real fun if there's not a little touch of improvisation in the organisation!

I had a first look at the feedback questionnaires. The students most liked the discussions and Dave's talk. We also had a lot of praise for the catering.

Among the suggestions for improvement of course the air conditioning was mentioned, as well as a need for more breaks (we'll take that into account for next year for sure!). Then we had a lot of of interesting but sometimes contradictory suggestions for "more" and "less theory", "more demonstrations" (yes, I agree, but that's difficult to organize) and "some derivations" (that's a tough one...). Many thanks to the students for all the useful feedback!

I would also like to thank all my colleagues who worked to make this happen: First Piera for all practical aspects. Paula and Ghislaine for the help with the catering. The already mentioned speakers of course, and everyone who joined the discussions. I can't possibly cite them all here!

27 March 2007

Un altro litro di vino rosso per favore

Ciao tutti; no doubt you have already guessed where I am. That's right, I'm in Slovenia, trying to hunt down that accordion player who kept us awake all weekend at our hotel near the ski resort of Cervinia.

No, not really. I am, of course, in Rome, my most favourite of eternal cities. My purpose here is twofold (threefold if you take into account my insatiable appetite for saltimbocca and pan-fried ciccoria).

Firstly (and in reverse order) for the second half of the week I'll be attending a CMS ECAL testbeam workshop at Rome University. The workshop has been organised to review testbeam activities over the past few years, discuss results, and, I suppose, ponder how what we have learnt from these programmes can feed into the first operational phase of CMS later this year. For myself, I'm going along to glean as much information as I can in preparation for our ECAL Endcap testbeam in a couple of months.

Secondly, for the first half of the week, I'm visiting my colleagues at ENEA (CERN canteen: please please please be more like the ENEA canteen). I've been working with them on how irradiation affects the uniformity of the ECAL's lead tungstate crystals. Unfortunately, the programme of research we envisaged has been plagued with problems. Initially with the photodetector I brought from Imperial and then a bigger problem with the ENEA gamma ray source which took several months to fix (you can't just walk in there with a screwdriver). But that's the way it goes sometimes in all fields of research and now we have to get on with the information we have and focus on completing the endcaps for the first LHC phyics run next year.

ENEA have also been producing supermodules for the ECAL barrel and tomorrow we'll have a ceremony marking the completion of the final supermodule. I've packed a nice shirt and smart trousers for the ceremony (I've ironed the shirt mam) and I'm looking forward to the good food and wine that invariably accompanies such celebrations in Italy. It's very exciting (yes, I admit it) to see the detector very near to completion, but, I suppose, also a little sad as all the small collaborations that were formed over the years to build the thing start to dissolve.

Ah well. I'll be consoling myself in Da Lucia in Trastevere this evening with some spaghetti alla gricia and maybe I ought to try the tripe (a Roman speciality). I quite enjoy dining alone. Once the initial acute self-consciousness is conquered and the first half-litre of wine given a good home, it's pleasant to watch the other people in the restaurant (especially the struggling tourists discovering Italian cuisine has nothing to do with Hawaiian pizzas and spaghetti bolognese). Oh and one last thing; should the nice girl at the Hotel Posta near Cervinia be, by some amazing chance, reading this, I meant to say something really funny and not mumble "arrivederci" and my phone number is 004176...

25 March 2007

D Zero week

A few weeks ago, the D Zero experiment had its collaboration meeting. As I have just started my PhD, this was my first time at the experiment, and indeed my first time in America! It was a bit of an adventure, which is why I have taken so long to write about it (I needed to recover first), but it was a good experience.

About D Zero itself; D Zero is a general purpose detector for the Tevatron accelerator. The laboratory (Fermilab) is essentially built in a nature reserve; originally, the land was all arable fields, but now it has been reclaimed as prairie land (complete with buffalo, coyote and all sorts of other animals). Obviously, it was fairly cold out there, but I was quite happy - until I 'found' that frozen stream, that is.

It was good to meet the people who work on D Zero; I have done Summer work at CERN in the past, and I found the atmosphere at the two laboratories is very different. I learnt a lot about the experiment itself, as well as how the collaboration works.

I was also able to spend some time in the city. I like Chicago a lot, especially the beach, the Art Institute and the Millennium park. I had a rather unfortunate experience at Lincoln Park Zoo, but it would be best not to go into details here.

Overall, I really enjoyed the whole trip; it was very valuable to me, and now I have a clearer idea of where my PhD is going.

20 March 2007

Mother Nature's Bumps

Last week, Dr Sam Harper visited us to talk about his PhD work at the CDF experiment at Fermilab.

Sam was an undergraduate student at Imperial HEP before he moved to Oxford to do his PhD (or whatever it is they call them), so it was a bit of a homecoming for him.

The talk was about a study of events at the Tevatron collider with two prominent electrons/positrons emerging from the collision of protons and anti-protons. This is a channel with good sensitivity to New Physics, because the events themselves are clean and well-defined, the expectation from the Standard Model is well understood, and because if there is something New that is contributing to the events, you can use the electrons to figure out its mass, although that does depend on the way the New thing turns into electrons.

Sam went through the different aspects of the work, from the motivation and analysis procedure through to the final "mass spectrum" that he found from the electrons. It is the mass spectrum which encodes any signs of New Physics, and in particular, any unexpected "bumps" in the spectrum (there is only one you expect to see, a huge bump at 90 GeV due to the "Z boson" discovered a couple of decades ago at CERN) would be a smoking-gun signal, if significant.

For an example of an undisputed, definitely significant, unexpected bump in the equivalent type of event, at the high energy frontier of more than three decades ago, check out the J particle discovery mass spectrum!

Getting to the mass spectrum was just two-thirds of the talk though. Because events occurring in the detector gradually build the mass spectrum up over time, there is always going to a be an inherent bumpiness in the spectrum at any one moment. So the rest of his talk dealt with a full statistical analysis, which demonstrated how likely it was to see such "accidental bumps" in the spectrum and of what size. The human eye has a natural tendency to see patterns even when there is nothing there, so you need an objective analysis like this to tell you if there might be something New there or not.

Whether there are any significant bumps, and other details of the study can be found at Sam's home page for the analysis.


All of this did remind us of other "bumps" in Tevatron data which have been the recent focus of discussion in physicists' blogs and the popular press.

The moral of this story is I think, that when Mother Nature responds to the questions you have asked her, listen carefully, and don't pick and choose from her answers....