The LHC inaugration and the LHCFest

The official ceremony of inaugration of the Large Hadron Collider (LHC) took place on 21.10.2008 which was attended by quite a few important people, especially from the CERN member states. There were also delegations from other countries from all over the world, the delegations typically headed by education or science ministers of the respective countries. There were also the guests invited by the Director General (DG) of CERN, which were mainly physicists from CERN and all over the world, and heads of laboratories and funding agencies.
The ceremony took place in the SM18, which is the testing facility for the LHC magnets. In one of its halls, expositions from all the four major detectors were set up, along with posters and displays of parts of the LHC magnets. So the guests were to visit this hall, where, apart from the science, they were also served the "molecular cuisine", which was an assortment of chef Ettore Bocchia's creations including the famous ice creams cooled with liquid nitrogen to maintain a velvety texture. I had the good luck of being there as one of the presenters at the LHCb exposition, and given my sweet tooth, I had a ball. And you can find me stirring the ice cream while liquid nitrogen is being poured!
Going back to the ceremony, the guests were then taken to another hall called SMA18 where they were to be seated for the rest of the evening. There was also an exhibition titled "Accelerating Nobels", which is a series of photographs of Nobel laureates who were asked to make a drawing of their Nobel discovery and hold it while posing for the photograph. Another interesting thing about the exhibition was the photographer's comments for each of the photograph, and the ones for Anthony Leggett (nobel prize 2003) were
"It’s quite a twist when atoms form pairs to allow for superfluidity, but Tony Leggett wanted to show exactly how they do it – with his hands! “But Professor, how can you hold up your drawing to the camera when you need both of your hands for your presentation of paired atoms?”, I ask. “Just tape the drawing onto me!”, he replies."
This is ofcourse my favourite picture....

The ceremony began with a speech from the DG followed by speeches by the distinguished delegates.
Then there was a concert named "Origins: concert for a collider", a celebration of the wonder of the cosmos and the glory of life on Earth, as expressed through the imagery of a nature photographer Frans Lanting and the music by Philip Glass.
This was the end of the formal ceremony and the guests left by 1800.
The LHC Fest, which was open to all CERN users, included a buffet and a concert, was to start from 1830. Both the exposition hall and the ceremony hall were open so one could look at the displays by the four experiments and the Accelerating Nobels exhibition. There was a speech by the DG and also a performance of "Origins" for the fest. After which, the buffet was served at 2030 and a concert followed, which was in full swing even as I left around 2300. It was a very enjoyable evening overall and I am glad I was able to experience this unique day.

Elephant in the room for the Nobel Prize in Physics!

On Tuesday it was announced that Makoto Kobayashi and Toshihide Maskawa have been awarded the Nobel Prize in Physics for 2008. The award is "for the discovery of the origin of the broken symmetry which predicts the existence of at least three families of quarks in nature." They share the prize with Yoichiro Nambu for his work on spontaneous symmetry breaking, a process vital to the derivation of the Higgs mechanism which gives particles mass in the standard model and which, as has been well publicised, is major part of the physics to be investigated with the LHC.

The work of Kobayashi and Maskawa concerns a slightly more obscure asymmetry in nature, so called CP violation. Essentially CP asymmetry reveals a subtle difference between the weak nuclear decays of some particles and their corresponding anti-particles and forms a cornerstone in the investigation of why the universe is made of matter and not anti-matter. It was first observed experimentally in the 1960s and at the time posed a theoretical conundrum. Kobayashi and Maskawa showed in the early 1970s that this effect could be incorporated into the standard model if there are at least 3 generations of quarks. This effectively predicted the yet to be discovered top and bottom quarks. Their work built on the flavour mixing formalism developed by the Italian Nicola Cabibbo and resulted in the so called CKM (Cabibbo-Kobayashi-Maskawa) matrix.


The ultimate test of the CKM matrix came this decade with the operation of the B Factories; BELLE in Japan and BaBar in the USA. These experiments produce pairs of B mesons (particle and anti-particle) and study their decays looking for the effects of CP violation predicted by Kobayashi and Maskawa. In 2001 both collaborations reported the first experimental observations of CP violation from B meson decays, completely in agreement with the CKM matrix formalism. They have since made scores of similar measurements all consistent with the model. Imperial College has been heavily involved with the BaBar experiment (named after the eponymous cartoon elephant who is also the experiment mascot) for the duration of it's running, which was completed earlier this year. We continue to work as part of the collaboration who are now analysing the final data set. Currently the Imperial group are looking at the effects of radiative penguin decays which can further constrain the elements of the CKM matrix.

It is the success of the CKM mechanism under intense experimental scrutiny which has made Kobayashi and Maskawa deserving winners of the 2008 Nobel Prize in physics.

A good time to leave the country?

Like the other first year students working on experiments at CERN, part of my PhD is to spend a some time living and working in Geneva. The other five are already here, but other commitments have kept me in London for the past year.

With the help of the UK Liaison office at I planned to come out at immediately after the RAL Summer School that has been written about before. Before I left for Oxford all my stuff was boxed and ready to be shipped out leaving me about a month after my rent ended there to live out of a rucsac.

Despite having picked the most difficult time possible to come out, only just after the LHC first beam event, I was found a studio flat in Servette. So on Monday morning I said goodbye to London and headed for Heathrow. A couple of hours later I was leaving Geneva Airport loaded with more baggage than was good for me and a faint sense of foreboding.

A bus ride later I was at CERN picking up keys, braving the User's Office and then trying to work out my way back to the flat. The next day my stuff arrived, only a few hours late.

On Wednesday we had the "CMS September Fest" to celebrate the first beam through the experiment, the cumulation of twenty years work for some (quite a humbling feeling, having only been working on it for a mere year). Perhaps 1000 members of the collaboration came to the surface assembly building at Point 5 for a night of food, drink and a live performance of the LHC rap video many of you have probably seen (with dancers not anonymous this time - Tom).

Unfortunately this was slightly overshadowed by the news that due to a helium leak there are significant delays to the LHC - at least two months for warm-up, repair and cooldown of the affected section, and it seems unlikely that there will be any collisions until early 2009.

And to round off an eventful week, within a couple days of cooking for myself unsupervised I managed to food poison myself and spend the remaining two days in bed. Apparently French isn't the only thing I need to brush up on...

Amputating the Spider

For the past two weeks, just under 70 first-year PhD students (including 9 from Imperial) have been locked away in seclusion within the walls of Somerville College, Oxford as part of the HEP Summer School organised by STFC and the Rutherford Appleton Laboratory.

With nothing to live on except masses of free food and coffee (if you were fortunate enough to be funded by the STFC), you would think we wouldn't have the energy to learn that much. But the gruelling, sometimes 9am-10pm sessions of intense teaching meant we probably came away knowing slightly more than before. A heavy dose of quantum field theory, QED/QCD and Standard Modelling satisfied even the most theoretically curious amongst us, and the experimentalists were probably not disappointed by the (admittedly collider-orientated) phenomenology lectures.

A stay in Oxford would be incomplete without a visit to its numerous pubs. We made sure to try a new one each night during the first week, followed by the King's Arms as it only closed at midnight. The most valuable lesson we learned from the school was that even if food and accommodation are supplied, you still end up spending the savings on liquid assets, and quite a few of us came away with much lighter wallets.

A trip to the Diamond Light Source was organised on the middle Saturday. We were given a quick talk about synchrotron radiation sources, then taken on a tour around the facility. The spacious, clean and relaxed control room was an eye-opener, given my only point of reference was that of MiniBooNE and ex-SciBooNE. After that was walking trip on top of the electron storage ring (video). We were assured that the metres-thick concrete would protect our delicate bits, and our hopes of a future generation. Finally we were shown one of the 25 beam line laboratories, one in which synchrotron x-rays are used to analyse biological crystal structures. Tea and biscuits followed, adding to our suspicions that the school was one elaborate plan to fatten us up and feed us to the LHC gods.

Speaking of which, the LHC Switch-On Day was not uncelebrated, with drinks provided by the organisers, and a couple of students went as far as to produce a model of the accelerator and experiments in cake form.

As for the title of this post, you will just have to go to next summer's school to find out what that phrase has to do with QFT. But if we are the spiders, and our legs are the shackles of first-year inexperience, then consider us amputees.

LHC start up

Amazingly nobody from the group has posted anything about the LHC startup. I'd hoped (and in fact promised Yoshi) to blog from the CMS control room yesterday but in all the excitement didn't manage it.

For those few who have no idea what I'm talking about yesterday the Large Hadron Collider at CERN was finally switched on after decades of planning and construction. Our group works on the CMS experiment, one of the two larger experiments at the LHC.

So what happened yesterday? Well the LHC is a 27 km long circular accelerator buried under the Swiss and French countryside near Geneva. Yesterday for the first time beams of protons were circulated all the way around the ring. The media coverage of the event was astonishing. Radio 4 covered it live (pleasing my mother very much) and journalists from all over the world were here at CERN all day. I think the best account from the perspective of our experiment can be found here. Plenty of nice pictures of events and a video. Perhaps a little technical in places, but I'd be happy to answer any questions on it. Hats off to Lyn Evans and company, if anything they made it look a little too easy!

So what does it mean? From a scientific perspective it's the start of a journey to exciting discoveries we hope. In the next weeks and months we'll be working hard to calibrate some of the largest and most complex scientific instruments ever built. From a personal point of view all the publicity will make it much easier to explain what I do for a living to people in the pub.

Decommissioning SciBooNE

We have just done something on SciBooNE that has become somewhat rare in the field these days: we turned off the detector intentionally! On 18 August 2008, the SciBooNE neutrino beam data run offically ended at 08:00 in the morning (CDT). It seems like only yesterday that we put SciBooNE together and observed the first neutrino events in the detector, but we have now finished all the data-taking and have decommissioned the detector. Many of the detector components will be returned to their respective owners, but the main bulky parts will remain the detector hall until someone else decides to use the parts or the hall.

When most people learn that we decided to end the run, they are puzzled and ask why, apparently in the belief that we must have been forced to end the run. In fact, we ended the run mainly because we have already collected all the data we need to achieve the physics goals we set out to achieve, and it's now time to concentrate on the analysis of the data. Far from being a sad occasion, it was actually rather triumphant. (You can see how happy our Run Coordinator Hidekazu Tanaka, Columbia University, was to end the run in the photo at right. Also shown in the photo is Zelimir Djurcic, Columbia, who was the last SciBooNE shifter. (Photo courtesy of Hideyuki Takei.)

We spent a couple of weeks dismantling everything in the detector hall and sorting out all the parts for shipment back to their places of origin. As usual for us, most of that work was done ahead of schedule. To help out with the work, many of our collaborators came to the lab, and we had a large influx of young students as well. In the photo at left you can see several SciBooNErs working on removing the multi-anode photomultipliers from the top side of SciBar. From left to right are Yuki Kobayashi and Shunsuke Masuike, Tokyo Institute of Technology, co-spokesperson Tsuyoshi Nakaya, Kyoto University, Joan Catala Perez, University of Valencia, and in front is Katsuki Hiraide, Kyoto University. (Photo courtesy of Reidar Hahn.)

Yuki and Shunsuke are two M.S. students who came to Fermilab (and America) for the first time just to help with the decommissioning, and Joan and Katsuki are two of our PhD students and they've both been out at Fermilab for years building and operating the detector and of course working on data analysis. Actually, Katsuki recently presented our first preliminary physics result at the ICHEP08 conference in Philadelphia, PA. You can see him in front of a pretty large audience of neutrino physicists presenting the result in the photo at right. (Photo courtesy of Herman White.)

To commemorate and celebrate the end of the run we threw a big party at Fermilab on 22 Aug. You can see the invitation to the party up at the top of this entry. (The photo in the

invitation is courtesy of Reidar Hahn.) We had a nice simple cookout and a friendly game of volleyball which, unfortunately, the SciBooNE team lost to the MiniBooNE team. I guess we can't win them all...

(Photo courtesy of Joan Catala Perez.)

Beam in LHCb

Its been a long time coming but sometime late on Friday evening, the first beam from the LHC passed through LHCb, one of the four LHC experiments. This was a big moment for all the members of the LHCb collaboration, some of which have been hard at work on the experiment for many years. There was much excitement when the first tracks were seen in the VELO sub-detector (see picture from our eLog by Malcolm John).



The LHC accelerator is a complex beast and so it must be coaxed into life slowly, one step at a time. Eventually there will be two proton beams counter-rotating and then colliding in the center of each of the experiments. That is probably several weeks (or months) away. In the mean time, the two proton beams are being injected into the LHC and then dumped on large metal targets after they have passed through LHCb or Alice (one of the other experiments). These beams are of much lower energy than those which will eventually be circulating, but they are still useful for testing both the LHC and LHCb.

Its now 3am and I'm on shift in the LHCb control room. We are waiting for a problem with the accelerator to be sorted out so that we can continue to test the radiation monitoring system. The control room is stuffed full of computers and screens showing all kind of information on the state of both the accelerator and the experiment. I've attached a picture showing the current state of the beam. The beam spot can clearly be seen.



I'm glad I am here at the beginning of running. We all hope that the next few years at CERN will provide lots of interesting discoveries about our world. That feels inspiring, even when stuck in an uncomfortable chair in the middle of the night somewhere close to a hypermarket in France.

I've got a fair few more shifts to do over the next few months, so I will try and post an update on how the commissioning of LHCb comes along.


Update:

The CERN press office has published an article on the tests discussed above. You can find the article here.

I thought, as I'm on night shift again, that I'd add a little explanation of what the picture of the tracks in the Velo actually shows. LHCb has been specifically designed to study the decays of so called B mesons - relatively heavy bound states which include a bottom quark. These systems are an interesting place to look for deviations from the Standard Model and to really test our understanding of nature.

The Bs have a relatively long lifetime and so we can watch them decay after they are produced. The Velo is the LHCb sub-detector designed specially for this task. You can find lots of glossy pictures of it here. It consists of a set of CD sized disks of Silicon which react when charged particles travel through them. The lines shown in the first tracks picture above show the trajectory as a group of particles traveled through the detector. These tracks are made by taking all of the points at which a particle passes through a disk and then trying to draw a line through all of the points. As we are still in the early stages of commissioning, parts of the Velo were switched off, which is why not all of the disks show up as the particles pass through them.

CRUZET3: Cosmic Rays in the CMS Tracker

With only a few months to go before the LHC is scheduled to turn on, the Compact Muon Solenoid (CMS) experiment at CERN is making great progress. Months of testing have led to this week's CRUZET3 results; the measurement of the first cosmic rays by the silicon tracker, a part of the apparatus in which Imperial College is heavily involved.

Figure 1. A near cross-section of the CMS experiment – the horizontal line in the middle is the beam-axis. The blue and purple cylinders are the silicon detectors, and the red cylinders are the muon chambers. The fluorescent green line is the reconstructed muon path, and the frog at the bottom is a disinterested observer.

Researchers from Imperial College are currently collaborating with around 3,000 scientists from thirty-eight different countries at the CMS experiment, where protons will collide with each other at practically the speed of light. Before the collisions finally happen, the whole set-up needs to undergo careful testing and re-testing in a process known as commissioning. This has been going on for the better part of the last year, and is slowly but surely approaching completion.

One of the most important things that need to be tested is the ability of the various trackers to register the particles going through them. Muons from cosmic rays are an excellent source of test particles - hundreds pass through our bodies every minute - and are therefore used for testing the various detectors on the CMS.

These tests are collectively referred to as CRUZET – a Cosmic Run at Zero Tesla (i.e. with CMS's large magnet switched off). The first two such tests, which took place in May and June, focused on the outermost sections of the CMS, the muon detectors. CRUZET3, which started on the 7th of July 2008, included the silicon tracker for the first time. This detector consists of ten layers of silicon immediately surrounding the collision, which help to provide a very accurate map of the particles' trajectory.


Figure 2: A view further away from the beam-axis, two of the ten silicon layers are shown in purple, and the relevant panels of the muon chambers are displayed in red. The muon path going through the entire experiment is more distinctly visible.

The complicated part of the operation, however, doesn't stop with the data collection. The work then involves translating the electrical impulses and digital signals coming out of the experiment to the pretty pictures you can see here. Precisely for this purpose, the computer programmers at CERN have designed a highly intricate piece of software known as Iguana. This programme achieves the seemingly impossible; combining particle physics with attractive design. That's one talented amphibian.

A simpler piece of software, Frog, achieves similar results with fewer user options and the 3D models are easier to generate. As you may have guessed by the small image at the bottom left of each of the pictures, Frog was the programme used to generate the images you see here.

The three figures in this article use some of the first data to come out of the CMS; a model of one of the approximately 100,000 muon tracks generated in the twelve hours of CRUZET3. The fluorescent green line is a reconstruction of precisely such a muon track, which, as you can see, went right the way through the experiment without entering the central cylinder. This particular muon, as can be seen from figure 1, just glanced the innermost silicon detectors (in blue), but made both an entrance and an exit from all the outer ones (in purple).

Figure 3: A close-up view of one of the silicon detector cylinders.

Figure 3 provides a less cluttered view of the muon's trajectory – nine of the ten cylinders have been removed, and replaced with the individual panels the muon hit on its journey. Figure 2 shows a 'muon's-eye view' of the experiment, with the green line very clearly going through the internal trackers as well as the outermost muon detectors (in red).

These models are among the first to combine data from the muon detectors with results from the silicon trackers; providing a glimpse into what the experiments later this year may be like. The CRUZET runs are now over, as all the useful experiments at zero Tesla have been run. What remains to be done now are the CRAFTs – Cosmic Runs At Four Tesla. Watch this space!

Article by Gilead Amit (IC) and Tom Whyntie (IC). With thanks to Christophe Delaere (CERN) for his help in constructing the Frog images. Frog was created by Loïc Quertenmont (UC Louvain) and Vincent Roberfroid (UC Louvain).

T2K is Coming Along....

It has been a few years since our group started working on T2K, and as with any experiment, initially there was lots of talking and designing and re-designing, but without very much to show for it all, at least in a form that can be appreciated outside of physics meetings.

But with less than a year to go till we start taking data (which is a scary thought), we now have some photos and videos to prove that T2K construction is right on track!
The picture on the right is something I generated a while ago from the representation of the T2K near detector in the computer simulations that we have been using to design and study it.
The movie shows the magnet coil a week ago, being put inside the red magnet, which has already been placed 20 metres underground in the brand-new detector cavern. All 900 tonnes of the magnet were shipped all the way from CERN just a few months ago. Note the uncanny similarity between the picture and the movie.... The movie is sped up by the way -- the workmen don't actually whizz about like that.
It is a proper experimental hall now, but on the right is how the "cavern" looked when we visited J-PARC 9 months ago in September 2007--barely a scratch on the surface!
The near detector is being built in the ground about 280m from the origin of the neutrino beam that is also undergoing construction, so that we will be able to measure the beam and understand the interaction properties of neutrinos well enough to be able to measure it again at Super-Kamiokande, 295 km away, which is the point of T2K.
The cage-like object rendered in brown in the picture at the top is what we call the "Basket". It sits in the middle of the magnet, and holds up the P0D, FGD, and TPC detectors inside. This was one of the UK responsibilities, and in this picture you can see our colleagues from up North inspecting it when it was finished. Since it goes inside a big magnet, the Basket, and everything else too, needs to be made of non-magnetic materials, and that was one of the things they checked.
I hope it goes without saying that the Basket is not the only thing we are building for T2K in the UK! The Electromagnetic Calorimeter, or ECAL, which the UK is responsible for, is also coming along nicely, as is the neutrino beamline itself. I think I'll save those for another post though....

We're all going on... LTA

Since the end of our coursework and final presentations there has been a steady stream of my fellow first year students leaving for exotic places and now it's my turn - off to CERN and Geneva on LTA.

An LTA (Long Term Attachment) is intended to get the students closer to our experiments as we try to make the transition from being clueless to useful in our adoptive teams - hopefully.

I joined LHCb and have already found it very useful being out here. CERN is the hub of activity for the (close to 60) institutions working on the project, whether based here or visiting, and I've had the oportunity to learn a lot in just a few short weeks.

Yesterday, I went underground to visit the experiment for the first, and maybe the last, time as it will be closed at the end of this week in preparation for the start-up of the collider. Many people have invested a lot of years and effort in the project and it was very impressive to see in all it's detail - even if it was difficult to reconcile the simplified diagrams that I knew with the mass of metal supports and cabling I saw.

As a UK-funded student, I'm living in a studio apartment arranged for me by STFC. It's in Geneva, close to the Old Town and about an hour's commute to the office at CERN. I recently got married and my wife has moved out here with me. She's finding plenty to do in the city, enjoying the relaxed atmosphere, shopping in outdoor markets and getting to grips with the local language.

French isn't essential here, with Geneva's large ex-pat community and English the common languge at CERN, but it helps to get the most out of what seems, so far, to be an interesting place to live.

In the control room

As we haven't had a post for a while, I thought I would write something. As I am sitting in the control room of the D Zero experiment, waiting for the beam to start up again, control room work seems like a good topic.

I will give a brief explanation of what the D Zero experiment is to begin with: I will try to keep the physics quite simple. D Zero is a colliding beam experiment at the Tevatron accelerator on the outskirts of Chicago. The Tevatron accelerates protons (hydrogen nuclei) and anti-protons to a high energy before colliding them. The collisions produce a large amount of energy, which takes the form of subatomic particles. These particles are then detected and analysed by the D Zero detector.

So far, so good. However, you have probably realised that the experiment doesn't work on its own: it needs a team of people to keep it running smoothly. A bit like the Marquess of Bute's wine, the D Zero experiment requires at least four people to be present at all times. These four are the CalMuo shifter (who looks after the calorimetry and the muon system), the Tracking shifter (who looks after the tracker), the DAQ shifter (who looks after data acquisition) and finally the captain, who co-ordinates everyone's efforts. I am trained as a DAQ shifter, so it's my job to make sure that the data is flowing properly.

The D Zero control room is a narrow rectangular room in the basement of the main D Zero building. There are long desks running along each side of the room, with numerous telephones, keyboards, computer mice, pens, wires and bells cluttering their surfaces: this is par for the course in most physics labs. My station is about halfway along the room, and above my desk loom various loudspeakers, whiteboards, soft toys, ringbinders, lists of telephone numbers and ancient post-it notes covered with faded handwriting. It is nine large computer monitors, however, which dominate the space above me. It is my job to watch these, in order to make sure that the experiment is collecting data as expected.

This isn't as difficult as it sounds; essentially I only really care about two screens: one which shows the rate of data flow (I begin to get worried if it shows zero), and one which shows any errors that are affecting the system. The rest will help me to identify any problems the system might have. Usually things can be fixed quite simply, but occasionally the problem is quite complicated. More often than not I will find that I need the help of another shifter to solve things (for example, if the calorimeter has an error, I need to work with the CalMuo shifter to fix it). If it is beyond us, it is time to call in the experts, but I have only had to do that once.

Things get a lot more complicated if someone needs to make repairs (usually to systems close to the detector, but not within it). When the accelerator is inactive, it is safe enough for teams to go into the collision hall to make repairs (there are stringent safety measures in place, of course). Because it is very rare for the accelerator to be off, everyone will come down to the control room at once to work on their particular system. These times require some co-ordination, as everyone needs the system changed in a particular way. Sometimes it can be hard to tell someone far more experienced than you that they have to wait for someone else, but usually someone more authoritative will help me out.

That is the busiest it gets though. Most of the time, the DAQ system is running well and doesn't need much attention. I have been on night shift (midnight to 8am) this week. This has the disadvantage of making me become nocturnal, but it is good in a way because I can chat with my friend in Hong Kong. I have also been playing "Limericks" with a friend in London to pass the time: we write a Limerick one line at a time, taking it turns to come up with the next line. The end results, to be frank, range from poor to absolutely terrible, but it helps pass the time.

Having worked in the control room, I now realise how much work it takes to run a major particle physics experiment. Before I started my PhD, I was under the impression that you turned the thing on, and it just ran, churning out great physics 24/7. I now realise how naive that was. But it makes me wonder about the LHC experiments: D Zero is tiny in comparison with them. They are planning to have hundreds of people operating these experiments at a time: how will they communicate with each other effectively? How can they organise themselves when a problem needs fixing? Do they have procedures to follow for any eventuality worked out in advance? And then there is the sheer size of the detector: when something breaks down, how do they intend to get to it to fix it? So, not only is the LHC a huge technical challenge, it is an enormous logistic and organisational challenge, and it will be interesting to see the solutions they come up with.

Whoops, that was a very long article... congratulations if you got this far! It is hard to say something exciting about something that is essentially quite boring, but at least it gives you an idea of some of the work that we have to do in particle physics.

The 2008 IoP Particle Physics Conference

Every year the great and the good of the UK HEP community (and a load of Ph.D. students) gather for the annual meeting of the particle physics group of the Institute of Physics. Over three days at the beginning of April the University of Lancaster played host to this year's conference.

The main programme was split into plenary sessions, which gave an overview of research in the field, and parallel sessions, which gave third year Ph.D. students (among others) a chance to present a talk about their research at a conference. The plenary sessions were great as they lifted your eyes up from your little corner of research to see something of the bigger picture (in the interests of shameful self-promotion of the Imperial HEP group, Prof. Jim Virdee opened the first plenary with a really interesting talk on the work that's been done to get the LHC detectors ready for LHC turn on, as well as some of the development that's been required to get to this stage with some really nice photos of how CMS has come together over the years) whilst the parallel sessions not only gave us third years a chance to present our work but also to see what everyone else has been up to (again, all the presentations that I saw by people from Imperial were excellent). There was also a poster session with a heavy T2K flavour, although there was a very interesting poster outlining the excellent work that's being done by the guys working on the Front End Test Stand...

As well as the academic program, an evening out in Lancaster and a conference dinner allowed for plenty of time to catch up with those who've been away on long term attachments (I think it was the first time that all of my year have been in the same place since our first year lectures!) as well as an opportunity to meet other people in the field. The night out in Lancaster saw a load of students do their best to take over a pizzeria, several very pleasant, very local pubs and (so I'm told) a closely fought drinking contest.

There was also an STFC Town Meeting during the conference, which given the recent funding problems, was a interesting introduction to physics politics. Never let it be said that physicists aren't passionate about what they do!

It was great to take some time out to be reminded of what we're all working towards, see what everyone's up to and catch up with people who haven't been around Imperial for a while but now it's back to the real world. I'm sure others can fill in any details that I've missed out...

Ouch, that hurts!

In spite of the somewhat appropriate title, this post is not about what STFC thinks about the LHCb experiment.


While I was searching for some material from my lecture at next week's Master Class I found the picture on the left. It's taken from the first episode of the the Big Bang Theory, a new sitcom now aired on Channel 4. For those who don't know it, it's basically like Friends, just with only nerds.

In the depicted scene (watch it) main character Sheldon supposedly explains some string theory to his neighbour Penny. A closer inspection shows that the white board has little to do with string theory. There's a simple calculation of the decay rate of the top quark to the bottom quark (assuming CKM unitarity) and then two Feynman diagrams of "FCNC" (flavour changing neutral current) top quark radiative decays. Finally there's a partial view of the CKM matrix. This scribble on this nerdy sociopath's white board could actually have been copied from my own white board (I mean, the one in my office). Ouch, that hurts!

The LHCb group at Imperial specialises in FCNC decays (actually of the b quark) as it is a very promising way of indirectly observing new particles too heavy to be accessed directly at a collider. They can hide in the loops shown on the picture (more). Many particles have been "discovered" indirectly this way before being actually produced directly at a collider. The race between direct and indirect will be on again when the LHC turns on.

Petition reaches 17,500 signatures. Thanks for your support!

Just a quick note to thank everyone who signed the online petition calling for government action on the STFC funding crisis. The petition has now closed and yielded an impressive 17,518 signatures. By the end it was one of the top 10 most supported petitions on the site. This is well beyond what any of us hoped for when we started out. Most encouraging was the depth of support from outside the affected fields, from the wider physics community to other areas of science and the general public. The petition attracted support from all levels of science, from the big names to undergraduates, many of whom organised a petition awareness day in physics departments nationwide.

The government's response so far hasn't been very different to the line they have been following throughout the debate "funding has broadly increased but tough decisions had to be made". However, the strength of support for the petition has clearly raised awareness of the consequences of the cuts both inside and outside of government. Hopefully this will help those negotiating to mitigate the damage.

Once again, thank you to everyone who supported the petition and spread the word. We have at the very least shown that science matters to more people than those holding the purse strings in Whitehall could have imagined!

Will

My Postgraduate Students' Physics Grandfather

Postgraduate advisor-advisee relationships often bring up discussions of physics genealogy -- for example the fact that students of my colleague Dave Wark, such as Ian, will share their physics grandfather with me.

Through all the variations such discussions can take, one common question is "what was my physics grandparent like?"

My advisor was Peter Fisher, and I was his first student, and there are lots of things I could say in response (and probably will), but it is not often that you can point to a clip from the Late Night with Conan O'Brien programme to answer the question....

So here he is in all his glory:
NBC Television(in the US), or, slightly more dodgily: A certain google-owned site

Sustainable Physics: SciBooNE's Recycling

Fermilab's daily newsletter, Fermilab Today, has recently published a nice article about SciBooNE. (Read it here!) The article discusses an interesting aspect of our experiment, which is that many of our detector components have been recycled from previous experiments. Our vertex detector (SciBar) and electromagnetic calorimeter (EC) both came to us from Japan where they were used very successfully in the K2K neutrino oscillation experiment. Actually, the EC originally was used in the CHORUS neutrino oscillation experiment at CERN, so it has been recycled twice---very good value for money! The third part of the detector is the muon range detector (MRD) which is made from iron and scintillators originally from the Fermilab hadron spectroscopy experiment E-605. (The photo above shows Joe cleaning some of the scintillators. [Photo courtesy of Fermilab Visual Media Services.]) We also used PMTs from a half dozen or more sources for the MRD. (The photo at left shows Hannah Newfield-Plunkett, an undergrad summer student from Cornell working on sorting out PMTs for the MRD.) We also used electronics for the readout of our PMTs and the data acquisition from the Fermilab equipment pool, PREP. This group at the lab is an enormously valuable resource and we really couldn't have built the experiment so quickly and inexpensively without them. To connect the recycled PMTs to the PREP electronics we also needed to find as many quality cables as possible because they are not cheap! We sorted through many thousands of old cables to find what we could use; they were stored in an old experimental hall which is now a kind of physics graveyard full of lots of old but still valuable and very useful equipment. The photo at right shows Michel Sorel and Joan Catala, both from Valencia University, sorting and testing cables. It was hot and dirty work!

The Fermilab Today article discusses all this work and more, and includes an audio interview with Joe. Check it out!