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...

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.

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....

The moral of the story is...

I was asked last week, by an American friend and colleague, whether London had any bad parts of town. I was a little surprised by the question, she has been visiting us here fairly regularly over the last 9 months, and I assumed she would have realised that, like all big cities, London has it's parts that you shouldn't wonder into. Still, I told her about my first flat near Finsbury Park, how Abu Hamza used to live and work near by, and how my flatmate would always finish his run a couple of minutes faster if he did it after dark. I even mentioned that one of the big delivery companies (DHL, I think) would deliver parcels all over Iraq, but would still avoid parts of E16, my current post code. At no point however, did I think to mention the dangers of Oxford Circus...

As most people know, last Saturday was St Patrick's Day and being an avid fan of the black stuff, I decided I wanted another St Patrick's Day Guinness hat. I got one in 2005, but it never really fitted, so I hoped that by 2007 this design flaw would be sorted. So I meet up with some old friends from my undergrad days, and we go to a nice pub called the Marlborough Head, near Bond Street station. We have a leisurely lunch, during which time I drink 2 pints (half way to my hat) and then we go off to do a little shopping (or get a hair cut in my case). About 3 hours later, we go back to the same pub, have a few more pints, watch Wales beating England at rugby (shame!) and some light pub food to tide us over till dinner.

At just gone seven, we leave the pub, Niall and I proudly wearing are hats, and decide to go to the Apple shop, on Regent Street before heading home. So we march of down Oxford Street, getting funny looks from some, amused glances from others and, unfortunately, undue attention from a rather inebriated Polish guy with a bottle of wine. It's something that seems to happen any time that one goes out in public wearing a silly hat, people come up to you, shout some appropriate phrase in you face and wonder off, all harmless and part of life. This guy, didn't wander off however, he wandered down Oxford Street with us, still yelling and the like, until we reached Oxford Circus. As we turned South, down Regent Street, I kind of hoped that we would part and it would just become another funny story, but alas he decided to keep following us, keep bumping into us and keep being a nuisance. So I asked him to leave us alone. He was 'disinclined to acquiesce to my request' and after being asked a second time decided to take a swing at me.

This is where things get a little hazy, I remember being hit (didn't really hurt), I remember swinging him into a wall (broke the bottle of wine) and I remember him deciding the neck of the bottle wasn't much use without the rest of it and he may as well throw it at my head. In all honesty, that didn't hurt much either, but seeing as we were both bleeding it seemed a fairly good time to stop fighting (personally, I don't think it was ever a good time to start...) and my friends led me off to find medical attention. One short taxi ride (and about 2 packs of tissues) later and I'm in University College London Hospital waiting for an X-ray and some patching up.

During my stay there, I find out that the wound is free of glass fragments (yay), my assailant has been brought to the same hospital and is now talking to my friends, not realising who they are (ahh), hospital security go past wearing stab proof vests (double ahh), the police arrive (better), ask me if I want to press charges (yep), I get patched up/flirted at by a cute nurse (yay, wait, I mean... 'I'm in a serious relationship') and give a description of what happened to a cute young police lady (not a statement, because I'd been drinking).

Three days later, the bandage that you can see in the photo has been removed, and more glue has been added, so that my ear now looks like this (little warning, not a particularly pleasant photo).

So, the moral of the story? I don't know really. It's not to avoid Oxford Street, that's for certain. Don't wear silly hats in public is a maybe, but many others seemed to enjoy that night. Don't drink sounds good, but I was far from drunk and little would have change if I was completely sober. I'm not even sure if there is one, but if you can think of a good one, feel free to comment...

Winter Seminar in Austria

This seminar was organised by the Institute of Applied Physics of Frankfurt University and is the 25th year that they've been doing this. The venue was a lodge, owned by Frankfurt University, about 200 miles away from Frankfurt in a region called Kleinwalsertal just over the border in Austria.

I have to say that I was a little bit unsure as to how the workshop was going to go, seeing as most of the talks were going to be given in German and I only know a few words of German. However, I was reassured that the slides were going to be in English. In the end I found most of the talks quite useful and it was good to meet other people working on similar projects to the one I'm working on. As is usual with this type of meeting there was a strong work hard/play hard ethic. The day from 9am to 5pm was free so that people could enjoy the local scenery and make use of the skiing facilities. Talks then started from 5pm and went on until about 10pm (with a break at 6pm for dinner). I've always wanted to try a bit of snowboarding so this was going to be a good opportunity! Four other students from Frankfurt and I booked ourselves on a 3 day snowboarding course. And so over those three days I became acquainted with how to land on my bum, with a snowboard strapped to my feet, in various snow conditions: hard snow, ice and wet slushy snow!
By the end of the first day I could go fairly quickly down the slope but hadn't mastered braking so would have to do a controlled crash kicking up large amounts of snow in the process. At one point a little girl skiing past offered to help me up (at least I think that's what she meant, she was speaking in German). I politely declined! By the end of the second day I'd managed to master braking but only if I was on the front side of my board (i.e. facing backwards). If I wanted to turn right I was in trouble! By the end of the third day I managed to master turning right and getting my balance on both the front side and back side of the snowboard. I was feeling confident enough with my abilities that I took a short video on my digital camera as I came down the slope!

This meeting wasn't all play though. As I said talks went from 5pm until 10pm and after a days snowboarding keeping concentration was tough. Everyone else at the meeting was from a German institute and so the talks gave a nice overview of the accelerator physics projects happening at various institutes across Germany. It was very useful to find out about other projects that are similar to the one I'm working on (The Front End Test Stand) since there is no project even vaguely similar to ours in the UK. I gave an overview of our project and showed my little snowboarding video at the end of my talk, which went down very well! I thought there'd be a few awkward questions since there were many experts in the audience and I'm really learning on the job (you find a lot of that in particle physics, i.e. having to learn something whilst at the same time having to implement that method or theory!). But, everyone was incredibly positive and some people felt that they could also learn from what we are doing.

On the whole, it was a very useful seminar. I learnt some physics, drank some German beer, made some useful contacts, learnt about other projects, learnt to snowboard but most importantly, got invited back next year!

First LHCb week at CERN

I'm out at CERN for my first LHCb week. Four times a year, everyone working on the LHCb gets together to discuss how things are going with the experiment. For me, it's a great opportunity to meet lots of people, some of which I've already been working with, and some who I will work with in the future. I've been here for 5 days already, and have found my time very productive.

I have been working on a software project called Ganga, a neat little Grid front end tool used developed by members of the LHCb and ATLAS collaborations. It’s been really good to meet other people working on the project and discuss ideas face to face.

There are lots of interesting meetings scheduled this week, and today I'm off to find out about the RICH detector and the "online" software (used during data taking). Later in the week, there are meetings on Physics and computing, which I am looking forward too, and a lecture by Michael Frayn, a well known British playwright. I’ll try to post a follow up to let everyone know how the week went.

The PhD End-Game (Thesis/Viva) Experience

So you start your PhD in HEP in Imperial by doing courses to get a grounding in the subject, work out (hopefully) what you actually want to do as a PhD during the rest of the year, spend the better part of the rest of the three years (or four, as it is now) desperately trying to create a cohesive piece of research, then bind the whole lot into a thesis. Easy.

Perhaps the strangest thing for me about writing my thesis was really trying to decide what point I was getting across. During a PhD you always end up working on a lot of different things, some of which you include and some of which have no direct relevance. Then you have a restriction on how long it should be. Mine was 170 pages, a little on the long side, but I actually left out a huge chunk of work on a medical imaging project called I-ImaS we worked on in the Silicon lab. It would have muddled the topic of the thesis, not to mention doubling its size.

In the end I decided that CMS was my primary focus, and the important work was on the off-detector trigger and readout electronics. As a CASE student I was in a slightly unusual position as my PhD was mostly about the hardware design of CMS, including the complexities of design, implementation details and possibilities for future upgrades. I also became heavily involved in designing and commissioning the Global Calorimeter Trigger (GCT), very late in my PhD. While it delayed my submission it also shifted the topics I chose to present.

Approaching things from a hardware perspective left me with an interesting dilemma when it came to the viva. What to revise? Hardware, analysis methods, trigger algorithms or more of the physics? As CMS isn't a running experiment this is more of an open-ended question than usual, and you can't know everything (there are, after all a few thousand people involved in the project for a good reason!). In the end I did a bit of everything, but (and perhaps this is due to the hardware nature of the PhD), I think that it's harder for examiners to relate to someone who's specialised heavily in hardware, as it's a less common trait in particle physics. Working on FPGAs and ASICs in Silicon requires a lot of specialised knowledge and isn't an area that's accessible to most physicists. (Incidentally, I think people often forget how lucky we are at IC to have a Silicon lab and an electronics workshop, not to mention some very dedicated and capable people to work with in both of them).

My external examiner was, (unfortunately for me!) very knowledgeable in FPGAs and the modern technologies used in CMS. I had a couple of very interesting discussions about the intricacies of 8b10b encoding in serial links... but one thing became clear during my viva. Virtually all the discussions were on topics I hadn't expected. This isn't to say that reading around the subject before the exam isn't useful, but it's worth remembering that you're partly there to be examined one what you don't know rather than what you do.

Which brings me to my conclusion on the experience. I think if you work hard, write a good thesis and contribute well to whichever collaboration you work on you'd have to work hard to fail in a viva. Your fate is most likely sealed before you even enter the room. For me I think the most useful thing about the viva was the clarification of what I didn't know. As I'm staying in research this is something I can work on!

T2K Workshop in New York

We are midway through a two-day workshop with our T2K colleagues, being held at Stony Brook University, on Long Island, New York. I have studied and worked at several US universities, but this campus really is the quintessential American campus for me, with windswept car parks each bigger than Imperial College, a "football" stadium, and everything being about twice the size that it needs to be.

Antonin our Research Associate has come with me from London, and our students Ian and Joe are here too. Joe is living in Chicago now to work on SciBooNE, so it has been a couple of months since I last saw him. He prefers now to support the Chicago Bears compared to the misery of following the perennial 2nd Division club that he used to have an interest in.

We are joined by our colleagues from UVic and TRIUMF in British Columbia, and some European universities, and of course the Stony Brook contingent. With only a couple of years to go till the T2K experiment gets going, we are working to make sure the computer software will be ready and up to the job. I will leave it to Antonin, Ian and Joe to add fair and balanced (and 99% censorship-free!) comments on how the meeting is being run. At least my choice of dinner venue was met with approval. I somehow think I will be judged on whether I will be able to bring the meeting to a close as scheduled, this being a Friday! We shall see come 6pm....