Posts on imperialhep.blogspot.com

Happy Christmas from the Imperial College High Energy Physics Group!

2011-12-25T23:30:00.000Z

The other day we had our HEP group party as we do every year, with about 80 group members and guests participating. The dinner buffet is always the centrepiece of the party, with dozens of hand-made dishes and puddings brought in by group members for everyone to enjoy.

The first year PhD students provided the main entertainment for the party, with their "Pin the Higgs" game, where we all queued up in front of a Higgs Boson mass plot to pin on it our "predictions", while blindfolded—although the clustering in the 120+ GeV range did indicate that this analysis wasn't as blind as it was meant to be! Whoever is closest if the LHC experiments discover the Higgs will win something highly coveted, I hear.... This is Paula going for the win:

...and Jordan claiming the region excluded 10 years ago by the LEP accelerator:

Later on, the party was raised to a yet higher level of sophistication:

with the proceedings coming to an end with a meticulously-rehearsed performance of "Last Christmas" by the PhD students....

Strangeness at LHCb

2011-08-18T14:57:00.000+01:00

New results were published from LHCb last week which will help physicists to simulate proton-proton collisions at the Large Hadron Collider. Members of the Imperial HEP group have measured two ratios of strange particles which give clues about how hadrons are produced.

The huge energy of LHC collisions allow physicists to look deep inside the protons to see interactions between the constituent quarks and gluons. Good predictions can be made for these high energy interactions using the theory of Quantum Chromodynamics (QCD).

Sometimes, the interactions of partons can produce "resonances", heavy particles like Z bosons which can decay to produce a shower of quarks and gluons:

Illustration of an LHC proton-proton collision.

These many-particle events are extremely hard to predict because of a surprising property of QCD: low energy interactions occur with more strength. If gravity behaved like this, you could make yourself heavier by moving more slowly, or lighter by running very fast -- sort of like a fat couch potato compared with a trim Olympic athlete.

As more and more quarks and gluons are produced their share of the available energy becomes less and less and the interactions get stronger and stronger until the quarks become "trapped" in groups of two (called mesons) or three (called baryons), just like the partons originally inside the colliding protons. This process is called hadronisation.

Hadronisation involves so many interactions that we cannot use QCD theory to predict what will happen. Instead we use approximate models:

“The predictions of the model are reasonable enough physically that we expect it may be close enough to reality to be useful in designing future experiments and to serve as a reasonable approximation to compare to data. We do not think of the model as a sound physical theory . . . ” – Richard Feynman and Rick Field, 1978

A popular model connects up all the partons with a "string" which snaps to produce mesons and baryons:

Hadronisation of a parton shower.

These models need to be tested against real experimental results. LHCb's strange particle results are useful because the strange quarks sit in a Goldilocks zone where they are light enough to be produced by the hadronisation process and yet do not provide a net contribution to the structure of the colliding protons.

The first ratio anti-Λ/Ks compares how often strange quarks end up in groups of 3 (the anti-Λ baryon) or in groups of 2 (the Ks meson):

This ratio is much higher in data than predicted by hadronisation models, so the models must be underestimating how often strange quarks group into 3s. And this underestimate gets worse with higher particle momentum (perpendicular to the proton beams).

The second ratio anti-Λ/Λ, compares how many times anti-strange quarks group in 3s compared to strange quarks. Protons are made of quarks, not anti-quarks (really less anti-quarks), so it should be easier to make Λ than anti-Λ. This behaviour changes with the angle to the proton beam, or the "rapidity" -- think of large rapidity as a small angle to the proton beam and small rapidity as a large angle.

LHCb is unique amount the LHC experiments with a view of the high rapidity (small angle) region. The anti-baryon/baryon ratio shows a significant change in behaviour across this region. At small rapidity data matches models which have already been validated at the Tevatron but at high rapidity the best match is PerugiaNOCR, a model with localised hadronisation, which uses shorter strings that don't connect all the partons together.

These results will be of great use to future developments of hadronisation models. It is very important to have accurate predictions at the LHC in order to test the Standard Model and search for new physics.
If you want to read more, you can get a copy of the paper for free. You may know that this is not generally the case for scientific publications. CERN has made special arrangements for all LHC results to be made freely available to the general public, in line with the spirit of its founding charter:

“The Organization shall provide for collaboration among European States in nuclear research of a pure scientific and fundamental character, and in research essentially related thereto. The Organization shall have no concern with work for military requirements and the results of its experimental and theoretical work shall be published or otherwise made generally available.” – Convention for the establishment of a European organization for nuclear research, Article II, Section 1, Paris, 1 July 1953

T2K’s First Ever Physics Publication!

2011-06-15T07:50:00.006+01:00

A week after our first paper, describing the setup of the T2K Experiment, I am happy to say that we have just submitted our first physics paper, and announced the results in seminars at the host laboratories.

Physics results are what our experiments are all about, and after many years of toil (as mentioned many a time here), it is a wonderful feeling, as always, to present to the world something about our Universe that no one ever seen before.

In the T2K Experiment, we create a beam of muon neutrinos at the J-PARC laboratory at Tokai Village on the eastern coast of Japan, and send them to the Super-Kamiokande neutrino detector 295 km away in the mountains of the north-western part of the country.
The mathematics that seem to describe well the results of other experiments—including Super-K looking at neutrinos in the atmosphere, KamLAND (my previous experiment) and many earlier experiments looking at neutrinos from nuclear reactors, SNO and others looking at neutrinos from the Sun, and MINOS and K2K with neutrinos made in a similar way to T2K but with different optimisations—suggest that with the specific energy and distance that the T2K neutrino beam has, we might be able to see a small fraction of the muon neutrinos turn into electron neutrinos.

This effect would be the third type of neutrino oscillation that has been seen.
The fact that it is the third type may make it sound boring and unimportant, but actually it is quite the opposite—the aforementioned maths tells us that if we see three, we have seen them all and that means that various other phenomena can be explained when you plug the numbers, that are given by the experiments, into the maths.

One of these possible phenomena we may be able to explain is the existence of matter in the Universe today, as opposed to all the matter and anti-matter produced in the Big Bang just annihilating into almost nothing, which is one reason we think it is rather interesting to measure these things.

Neutrinos, on the rare occasions when they indicate their existence by colliding with the atoms that make up matter instead of just passing through it, tend to create the particles that they are labelled with in their names—muon neutrinos create muons, and electron neutrinos create electrons—Super-Kamiokande is very good at distinguishing muons from electrons, so we basically point the beam at Super-K and count the number of times we see electrons created by neutrinos.

Of course, it isn’t quite that simple—the beam is pretty messy to start with and hard to understand (just like almost anything that has to do with neutrinos), and lots of other things can mimic electrons created by neutrinos, and it is the job of we experimental physicists to do our best to sort these issues out, and most importantly, understand them enough that we can estimate what their effects are.

Once we do all that, we get the plot that is shown at the top of this blog entry. This is what we have worked so hard for so many years for!

We previously calculated that if this third type of neutrino oscillation doesn’t exist, we would have seen about 1.5 electron neutrinos (on average) in the data we took over the year or so since the T2K beam started. That is the shown in the plot above by the yellow, green and blue hatched areas.

One and a half.

But in fact, when we looked at the actual data collected, we saw 6, as shown by the black points in the plot above.

SIX!

This is consistent with this new type of neutrino oscillation occurring!

If we put in this new neutrino oscillation at quite a large level, it looks like the red region in this plot:

which shows that the data does look a lot like neutrino oscillations!

But....

Here I have to make it clear that what we see now amounts to what we refer to in physics as an “indication” or a “tantalising hint” to employ a common cliche.

We set up experiments to learn about the Universe, but it often doesn’t just respond with simple “yes” or “no” answers, but it gradually gives us a picture that becomes clearer with time.

In our case, it could easily be that the true average rate of electron neutrinos appearing is much smaller, but we were just lucky and a few came in in quick succession by pure chance.

To make a discovery of the sort that T2K is aiming for is to contribute something new to the current understanding of how the building blocks of the Universe are, and this will affect how we build future experiments, and how we interpret the information that comes from other experiments, and how theoretical models of the Universe are built—so we don’t take it lightly.

What we do know is that if we can send more neutrinos to Super-K, we’ll be able to tell for certain what is going on.

Most importantly of all, the T2K experiment is clearly working well, and it can be seen how well it has been optimised for our measurement, which is why with just a few percent of the beam that it was designed for, we can see anything like this at all.

Here is a press release: http://www.kek.jp/intra-e/press/2011/J-PARC_T2Kneutrino.html and a copy of the paper we have submitted to the journal Physical Review Letters.

Unlike the paper from last week, the paper hasn’t been accepted yet, as it has to go through a lot of peer-review to make sure that the community will accept the results that we have shown.

The data we used for this result is from between early 2010 and the afternoon of the 11th of March 2011, and right now, the beam isn’t running because of the of the earthquake—which hit Tokai village very hard indeed.

Recovering from the earthquake and preparing for future data is what a large fraction of T2K collaborators are working on now, and this will continue for a while. It is very satisfying in the meantime, however, to be able to produce results like this that show the world what an exciting time it is for the experiment.

I’ll finish this post with a photograph of the T2K Collaboration that was taken a month ago during a hectic series of meetings when we were working on finalising this result:

Spot the Imperial group!

T2K's First Ever Publication!

2011-06-09T11:56:00.004+01:00

As avid followers of this blog will be aware, a group of us here at Imperial HEP have been working on the T2K Experiment over the past several years. Personally it has been seven years since I got started on T2K, although it certainly feels like much more!

All these years of toil, and we had nothing to show for it (especially in the "metric-based" world we live in today), so I am happy to say that we have just had our first paper accepted.

It isn't a paper on a physics result though, but what we call a "NIM paper", because it is being published in the journal Nuclear Instruments and Methods in Physics. This is where physicists describe the novel setups and techniques they are using to conduct experiments.

Often this sort of paper takes ages to get out because physicists tend to prefer to spend their time running and maintaining their detectors rather than writing about them, but somehow the T2K Collaboration has managed to get its act together and describe the experiment over 33 highly entertaining pages, before we have any physics results out!

Particle physicists invented the World Wide Web to help us exchange information freely, and in that spirit, anyone can access the paper for free on the arXiv site: http://arxiv.org/abs/1106.1238

Three of the pictures in the paper are mine, including the "Exploded ND280 Detector" picture that I made four years ago, shown above. I'd be the first one to admit that it isn't a work of art, but it seems to do the job!

So, we've described the experiment in detail in this paper, but the question is, where are the physics results?

Well, it takes time to collect enough data for an experiment to be able to start discerning new things about Nature, and it also takes time for physicists to interpret that data -- so it may be a while, but I can guarantee that we are working very hard indeed on it!

Imperial High Energy Physics Group Open Day

2011-01-06T14:55:00.006Z

Happy New Year!

We will be holding a Group Visit day on the 19th of January, for anyone who is considering joining our group as a PhD student. If you would like to come and talk to us, please email my colleague, Dr David Colling!

My summer project at Imperial

2010-10-04T12:45:00.008+01:00

After spending my last 3 months with this department over the summer, I wanted to share my experience with you via this blog. Either that or I was strongly encouraged by my supervisor Yoshi! I am a 3^rd year undergraduate here at Imperial and I worked in HEP over last summer as part of a UROP (http://www3.imperial.ac.uk/urop) scheme.

Although not as extravagant as other blog entries on this site, with students travelling to Japan and Switzerland, my placement in the Blackett lab was just as enjoyable and rewarding. I was working with Yoshi and Ajit on the COMET experiment. In particular I was using computer simulations to optimise both a collimator and the fantastically named lagger-tagger, a name that Yoshi is still trying hard to get adopted by the particle physics community (hopefully not in vain).

I spent most of my time working with Ajit, who was very helpful, giving me lots of his time and expertise. His crash course in particle physics allowed me, who had not studied the subject yet, to understand enough of what was going on to do my project. I started by getting familiar with some of the tools of the high-energy physicist. First on the list was the hilariously steep learning curve required to use ROOT, and its 20 years worth of quirky workarounds, providing endless fun for the data analyst (I also wonder if the Windows version of ROOT is called Administrator). Second was G4beamline, a brilliant piece of software, with documentation so in depth and confusing that presumably only the person who wrote it can use all of its myriad features with any degree of confidence. Joking aside these are impressive programs, testament to group collaboration over years, and they allowed me to complete my project without much hassle at all.

The next part of my work was at the Daresbury Laboratory, working as part of the team building the detectors for T2K. This was useful as I could see another stage of an experiment, its actual construction, rather than its design. When I received the email telling me that the detector I had worked on had been shipped out to Japan it gave me the feeling that I had provided something real to an huge multinational experiment.

Another enjoyable part of my work over the summer was the opportunity to be a part of a research group, thankfully the High Energy physics group was welcoming and I got on well with all that I met, meeting for lunches and the occasional night out. The experience has convinced me to do a similar project next summer and to apply for a PhD place after my degree.

All in all I had a great time doing my UROP placement here, it was hard work, but very rewarding. Looking around this blog, I have only one regret, that I didn’t take more photos of myself smiling, standing in front of physics equipment.

Thanks to Yoshi and Ajit for their time.

Dave

CERN and first collisions at LHCb

2010-04-19T21:44:00.012+01:00

The last few months have been very exciting here at CERN. Ravi and me are currently on a long term attachment (LTA) at CERN in Geneva, working on the LHCb experiment. Both of us have been out here for nearly a year now and a lot has been happening during this period. We experienced the entire process of the LHC being repaired, new start up dates getting announced, etc... and of course working with monte carlo simulated data only so far!
But since last year things have changed as I am sure most of the readers of this blog will know. In November we saw the first beam circulating in the LHC after its repair. The LHCb detector was in good shape: Before Christmas LHCb was recording its very first data (it could not detect cosmics before due to its horizontal alignment)! Meanwhile the LHC people were testing their machine extensively in order to be ready for the official date of first 3.5 on 3.5 TeV collisions a few weeks ago (30.3.2010)... And it was a huge success! Since then LHCb has been taking several million events, stored and ready to be analysed (for example by PhD students like Ravi and me). So far we have done a pretty good job :) I want to point out Ravi being the first one to see hints of a D0 peak in the collaboration (and me hunting J/Psi peaks)!
The following picture was taken on 30th March, at 12.59, in the LHCb control room, showing Andrei Golutvin (in the red jumper, LHCb spokesperson and my supervisor) watching the LHCb event display showing first collisions (notice the two green muon tracks, coming from a J/Psi?):

It is a very exciting time to be here at the moment. Being part of this unique science community is truly special. Everyone who has been at CERN knows what I mean - at this place history in particle physics has been written. This becomes obvious every day - for example when walking past the Gargamelle bubble chamber, Tim Berners-Lee's office (where the "web" was born) or Jack Steinberg in person (actually, he is in the office opposite to mine and sometimes asks for help with his computer) - just to mention a few occasions. CERN also organises events and lectures: To celebrate the LHC an incredible number of Nobel Prize winners of the field came together last year and gave highly interesting lectures stretched over two days. Gerard 't Hooft was even so kind to be in a picture with a few IC students (and ones that used to be):

Of course CERN's location between the Swiss/French alps and the Jura offers many opportunities to throw yourself down a mountain on some sort of ski or snowboard. So during the long wait for the turn on date a common activity of the UK PhD students here at CERN was to organise numerous trips to Chamonix and other resorts. It should be mentioned that Ravi won the prestigious CERN ski club downhill race in a new record time (~2.13 minutes)- well done! However, the season is over now, and the summer is about to start here in Geneva. The LHC is running, LHCb is recording data... Everything seems to be working very well, and - touch wood - hopefully it will stay like that! An interesting time lies ahead, and Ravi and me hope to witness signs of new physics here at LHCb!

First Neutrino Seen at Super-K, 295km from the T2K Beam Origin at J-PARC

2010-03-05T12:09:00.005Z

This is the first neutrino created at the J-PARC laboratory, and sent across from the eastern coast of Japan, that was seen by the Super-Kamiokande detector, 295km away.

The picture shows the inside of the Super-K experiment, which is a vertical cylinder, filled with water, 40 metres high and a kilometre underground. The band in the middle is the side of the unfolded cylinder, and the two black circles are the top and bottom. The coloured blobs show the particles of light that were seen by the photon detectors that cover the inside of the cylinder, and the colours depend on the time when the light arrived there.

The rings that you can see formed by the coloured blobs are from the "Sonic Booooum" of light that made by the the particles that are created by the neutrino in Super-K. There are three rings -- the first two are bright yellow and obvious, but there is another one hidden there....

This is another image, with light-blue rings superimposed on it showing where the computer thinks they are. Making sure that we catch all the rings and interpret them properly is really important to get the right results out of our experiment.

There will be more to come, and when we see them we'll learn more about neutrinos, which can in turn tell us more about how our Universe came to be. For now though, we're happy that all parts of the T2K experiment are now working, from the beam, through the "near detector" that we built at J-PARC, and of course Super-Kamiokande.

We done to everyone who has been working all these years on T2K, and may the physics commence!

My first few months in Japan

2010-01-11T04:44:00.013Z

The last few months have been very jam-packed and exciting, and so I thought that I would write a blog entry to share my experiences (and also, my supervisor, Yoshi, has been asking me to write one for months!). I am a second year PhD student working on the T2K neutrino experiment, and I moved to Japan a few months ago in September 2009, to live on-site. Having spent a rather frantic weekend bidding farewell to friends and trying to cram my life for the next year into 2 suitcases, I was finally on my way to the airport and en-route to Japan! I felt a mixture of excitement and apprehension as I took off, and so decided that the best thing to do was sit back and enjoy the facilities of Premium Economy on Virgin. I drank my glass of champagne, switched on the movies and settled into my larger than average seat for the 12 hour flight. (I should add that this was somewhat of a treat since all the economy seats were booked for that flight, and so it should not be expected by future students - sorry about that!) Having arrived in Japan and feeling rather tired , it was time to get my luggage, which turned into rather more hassle than expected. Despite assurances by Virgin that it would be very easy to pick up my second suitcase which had been shipped as cargo, myself and Gil found ourselves 3 hours later still hunting around an industrial park at Narita Airport looking for my suitcase! Thank you again to Gil for staying behind and helping me out! I definitely wished at that point that I had been more 'male-minded' and only packed one suitcase. However, after this slight delay, we boarded the coach and a couple of hours later I found myself in Tokai, my home for the next year. One of the first things I spotted was a McDonalds, which made me very happy , since I had been worried that I would only be eating raw fish and rice!

Fast-forwarding a week or so, I was lucky enough to visit the Super-Kamiokande detector, a huge underground tank filled with 50,000 tonnes of water, on the west coast of Japan. The neutrino beam is characterised by the "near detector" in Tokai on the east coast (where I am living), and then travels through the earth towards Super-Kamiokande on the west coast. As we drove up winding roads into the mountains, I was awed by the beauty of the area. A wonderful mountainous landscape, shrouded in mist and clouds. I was also struck by the remoteness of the location. We were staying in a town called Mozumi, which consists of about 20 houses and one Post Office. Entering the mine and standing on top of the detector for the first time was very impressive; a vast dome shaped cavern filled with cables and electronics huts which feed the tank below, lit by rather eerie green tungsten lamps. It was excellent to finally see the detector "in the flesh" from which I had been analysing data for the past 6 months.

That was about three months ago, and since then I have been living and working in Tokai. It has been an extremely exciting time, and lots of hard work! I consider myself very lucky to be on the experiment during this start-up stage, since there is a wide variety of tasks to get involved in, and a constant stream of new developments. Since the near detector is still under construction, you can go down "the pit" and actually walk around inside it. It has been very fun to take part in some "hands-on" construction work, for example, installing the water system to cool the electronics. With all of this excitement of course comes an intense work schedule. The hours are long, there are meetings at all times of the day and night due to the multiple time zones of the collaboration, and many tasks to juggle. It has been extremely tiring, but I feel that I have learned a huge amount in these past few months. It is good to be on-site and at the heart of the action, where everyone is working together towards a common goal. The control room was buzzing whilst waiting for the first beam shots to be fired!

Having said that, it is not all work, there is a lot of play too! Myself and the other students have visited Tokyo many times now, and seen and done many weird and wonderful things. There are too many things to describe here, but a particular highlight was going to the bar from the film Lost in Translation. The view was absolutely spectacular, making the extortionate prices well worth it (£ 15 equivalent for a glass of wine!). We have also been to a robot show and seen a scarily convincing android, stayed in a capsule hotel (not as unpleasant as I'd expected!), and accidentally got caught up in a Windows 7 launch party. I wanted to try the Windows 7 burger from Burger King (a tower of 7 burgers in one), but the queue was over an hour long. I have also been dragged on a horribly fast rollercoaster, which apparently goes through the middle of an office block and affords great views across Tokyo, but I wouldn't know because my eyes were tightly shut!

And there was of course the infamous Tokai halloween party!

All in all, it has been a very eventful and action-packed few months, and I am looking forward to the rest of my time here.

Super-K Sonic Boooom!

2009-11-06T08:49:00.009Z

(photograph by Nick Ballon)
Well done Tom indeed, but we on T2K are also mixing it up with non-physicists (and artists), in our case in an artist's rendition of Super-Kamiokande, built under London Bridge Station, complete with accompanying sonic booooums....

Super K Sonic Booooum
Nelly Ben Hayoun, sound by Tim Olden
Wed 4 to Sat 14 8pm
Come on a fantastic voyage on a dingy that floats on 50 000 tonnes of extremely pure water where neutrinos interact with electrons in a massive Sonic Boom…Take part on this risky experiment with unique insights from scientists from Imperial College London and Queen Mary University who works with the Neutrino Observatory Super K and T2K in Japan, as SNO in Canada.

www.nellyben.com

This is in the amazing Shunt Lounge, and will be on Friday 6th and Saturday 7th and again from Wednesday 11th till Saturday 14th.

Everyone is welcome, but you need to be there at 8pm for the full experience!

And not only this, but as you can see from the advert:

Scientific Talks at the Sonic Boooum
Nelly Ben Hayoun
Wed 4 to Sat 14
Nov. 4th Dave Wark
Nov. 5th Ryan Terri
Nov. 6th Yoshi Uchida/Melissa George
Nov. 7th Yoshi Uchida/Melissa George

Nov. 11th Matthew Malek
Nov. 12th Ben Still
Nov. 13th Dave Wark
Nov. 14th Francesca De Lodovico

there's a chill-out zone where you can enter the trance-like state that can envelop you when you experience a... physics seminar. Hmmmm....

Photos forthcoming.

Three Minute Wonders

2009-11-01T23:23:00.014Z

As the Large Hadron Collider gears up to getting proton collisions before Christmas (fingers - well, pretty much everything, actually - crossed), I'm pleased to announce that my "Three Minute Wonders" will be broadcast this week - Channel 4, Monday and Thursday, both at 12:30pm.

As part of the prize for winning FameLab 2009, I got the chance to turn two of my three minute speeches into Three Minute Wonders with Wall To Wall Television. Directed by Peter Sweasey, "Finding Nothing" looks at why a null result would actually be a tremendous return on a £5 billion investment (based on my final-winning talk, below), while Thursday's episode takes a look at the search for Dark Matter at the CMS experiment.

It's not hard to imagine that the current economic climate will lead to a smaller funding pot for science, and that all areas of research are going to feel the pinch. The field of particle physics is no exception. It is therefore essential that we, as responsible researchers, continue to justify why we're doing what we're doing to the politicians holding the purse-string and the tax-payers who we rely on for our very existence - whether it's showing how technology and expertise are being transferred back into UK industry, inspiring the next generation of scientists and engineers, or simply reminding us that projects like the LHC should make us all, as a fellow outreacher Zoe Matthews (Birmingham) beautifully put it, "proud to be human beings". Hopefully films like these, and the work of all those involved in particle physics outreach, will help. I am therefore immensely grateful to NESTA, Channel 4, FameLab, Cheltenham Science Festival, Wall To Wall, Peter Sweasey, the CMS Secretariat, the CERN Press Office and my colleagues in the Imperial CMS group for the fantastic opportunities provided, their much-needed help and (sometimes considerable) understanding of what's involved in making six minutes of television.

Enjoy the films - and let us know what you think!

PS: Once they have been broadcast I think they'll be made available online - I'll try to provide more information when I have it.

PSI test run

2009-08-17T01:18:00.007+01:00

From the 10^th of July to the 3^rd of August I went to Switzerland to join the Mu2e test run at PSI. The story goes like this..

When I arrived at the airport I bought the tickets for my train that was going to Brugg. I wanted to get the direct train that was leaving in 5 minutes so I started asking people were to go to in order to get the correct train. I find the train (that was ready to depart at that very second) but as I wanted to make sure I was getting the correct one, I asked the ticket collector “Does this go to Brugg?”..with my accent and all it sounded like I was asking for “Prague” and he pointed me at a totally different direction (thank God I realized he couldn’t understand me, I showed him the ticket and he said “Aaaa Brugg, yes this is the train”..Ok, got the correct train...Now what about the bus (and the wrong accent? And the French and German I don’t speak?)... Well, lucky for me, people at Brugg are very friendly and very helpful. This village is small and everyone is very calm and polite (the bus driver doesn’t have a glass that separates him from the passengers-wao!!). I get the right bus, I go to PSI, and I call Peter Winter (the post-doc of UIUC) to tell him that everything is ok etc. A “Peter” answers, he tells me they are just going to get dinner and where should I meet them. When I met him and we introduced, I realized he was Peter Kammel (the head of the experiment and not the post-doc) I was talking on the phone with... Anyway, we get to the dinner place, the nice restaurant of PSI called “OASE” (I still don’t know if it’s initials for something or if it’s from oasis..), I meet the UIUC group I was going to work with: Justine, Chris, Michael, Alex, Greg. They let me know that tomorrow they are going to the supermarket (only one in the area) to get some food for the barbeque they will be having. The barbeque was great, we chopped woods (I liked that a lot :P ), my radiation pad started beeping for no reason, we saw that if I really had that amount of radiation I was going to be dead. After that they started calling me “the source”:P They tell me that the day after they will go for hiking to the Alps. Peter K. turns to me and says “Enjoy these 2 days because not every day is like this, we usually have a lot of work every day”-that’s what they were telling me all the time-and guess what: they were honest..I will talk about it in a second).

Left: Chopping woods, Right: The Mu2e team

The hiking was great!!! Amazing!!! But my stamina was not! I had to follow them (literally, as they were climbing the mountains like it was a straight way... At that point I thought it will be a good idea to quit smoking-then of course I changed my mind).

From the left: Claud, Michael, Chris, me, Alex, Greg getting some minutes of rest

The day after I go to the area we were working at. I meet Haruo from Los Alamos and we started working on the Neutron detector... When they said there was a lot of work, they were not kidding. We were there every day, not only for our shift hours (8-9 hrs) but more than that. And not only because we had to, but because we also wanted to. Being present at a run of an experiment and watching it live, how everything works, is very fascinating! Working on the hardware is something I personally enjoyed: the targets, the detectors, the wires, using the drill. After finishing with the hardware, whenever there was a run, we were no longer allowed to be inside the area. The software begins.. I feel I learned a lot (A LOT!!) in a month just because I was working with these people. We were all in two offices and there was always someone that could help, with the questions, with the code. I liked the organization as well. We were all submitting what we did in an eLog and every day at 5 pm we were having a one hour meeting, saying what our next goal is. Everyone had a new task to do, and that was something I liked. You were doing something and as soon as you were done with it, someone else was using your results to do his work, then you had a new task to do and so on. Work, work, work, but in a very enthusiastic way!

Left: The Vacuum Chamber and the two Neutron Detectors, Right: Inside the Vacuum Chamber, the two Silicon detectors, and in the middle the Aluminum Stopping target.

The tent we used to cover the experimantal setup as the humidity could affect it.

After midnight I was going to get some sleep at the guest house. The best people ever can be found there! Physicists, engineers, chemists from all around the world that were at PSI for a short term as well, were sitting outside the guest house, relaxing next to the fire. Very nice people! The Spanish were cooking Spanish omelette, we drank French wine. Oh, I also met a Greek there with whom we started talking in English before realizing that we speak the same language :P

People from the guest house

One day before my leaving, I went to Geneva to meet my classmates: Ravi, Paul, Pavel, Alex were there and we all together enjoyed the Independence day of Switzerland! I drove Ravi’s car at CERN (hihihi) and they gave me a tour in Geneva. Amazing time!!!!

(From left) Asen, Ravi, me, Pavel and Paul at CERN

This was a very nice experience and I would recommend this to any student!

The 35th Bubble Chamber Tournament

2009-06-14T02:40:00.011+01:00

A few weeks ago, on a Sunday, I was woken up at 7am by some of the loudest thunder I had ever heard, and looked outside to see torrential rain banging on the balcony. My first thought was "well that's the end of this year's Bubble Chamber Football Tournament...." Later on I was to learn that many of the tournament participants were greeting by the storm as they were driving down the motorway on the way to London.

As it turned out, by the time we all gathered at the Imperial College sports grounds in Teddington, the sun was out, the sky was blue, the pitches were dry, and 9 out of the 10 teams had arrived, ready to battle it out for the coveted trophy.

I applaud all the teams from making it down from afar in spite of the weather. Sadly, one team was not able to muster up the courage to travel to lovely south west London. Anyway, enough about those losers....

The Imperial College HEP Teams

Imperial fielded two teams, the first, the Golden Generation of first-year PhD students and others led by Simon and Ajit, and the second, led by Jordan our group leader with Julian, a 23-year veteran of Bubble Chamber tournaments, in goal, and me wandering about not doing much on the left.

Here is some match action, with Ajit doing something highly technical with his right foot:

and Manchester 1 defending against Liverpool (well, a ringer from Queen Mary, rather):

Imperial 1 and Manchester 1 made it to the semi-finals, but lost to Birmingham and Liverpool (+QM) respectively, who fought it out in the final:

So here are this year's results:

Winners: Birmingham
Runners-up: Liverpool (+ Queen Mary)

Troll: Oxford 2
Biggest Losers: UCL for being put off by a spot of rain

The triumphant Birmingham team:

and the trophy presentation at the pub down by the Thames:

We think Birmingham agreed to host next year's competition -- so see you all there for the 36th Bubble Chamber tournament!!

Imperial HEP in the spotlight

2009-06-02T14:00:00.009+01:00

Afternoon,

Outreach has always been a strong part of Imperial's High Energy Physics group - indeed, the "Particle Physics Masterclasses" were a big factor in my decision to go into the subject. That's why it's an honour to be representing Imperial at the NESTA FameLab 2009 competition - a sort of "Pop Idol" for scientists - with £10,000 and a few Channel 4 "Three Minute Wonder"s up for grabs at the National Final at this year's Cheltenham Science Festival.

I won the Oxford regional heat with a three-minute talk about the search for Dark Matter at the CMS experiment - something the Imperial group is very strongly involved with, which of course nicely complements the group's involvement with Zeplin. The competition was tough - two Oxford "wildcards" also made it through to the final - but the day was an incredibly rewarding experience, providing the chance to meet and get some feedback from some of the top science communicators in the country. A big thanks to the FameLab team, who made the day such a joy to take part in - and to those who gave me the chance to develop my shows/technique with lots of practice (particularly during National Science & Engineerin Week). Outreach is difficult, and it takes time - but particularly when everyone is thinking very carefully about where their money is going, it's essential that we as scientists not only justify what we're doing to the UK tax payers, but also inspire them to really think about the mind-bending implications our results could have for our understanding of the Universe in which we find ourselves. Hopefully things like FameLab can help.

The final is this Friday (5th of June). I've spent a weekend with the other ten contestants for a "Masterclass" session, and they were all fantastic to work with and are certainly all worthy of winning - so it'll be down to the performance on the day. Whether I "Boyle" it, or really give our friend Prof. Brian Cox something to worry about, I'll keep you posted ;-)

You can also catch me at the Royal Institution on Tuesday 9th June, where I'll be giving my "Whatever is the Matter?" public lecture about the LHC-based search for Dark Matter - the hypothesised "missing fifth" of the Universe.

Oh, and 10 points for anyone who can guess what I'm doing with my hand in the video.

Bubble Chamber Football Tourmament

2009-05-08T08:37:00.006+01:00

Bubble Chamber Football Tournament 2009

hosted by Imperial College High Energy Physics

7 June at the Imperial Sports Grounds at Teddington

all are welcome, as players or as supporters

See Simon Jolly's Bubble Chamber Tournament Home Page
(http://www.hep.ph.ic.ac.uk/~jolly/bcc/)

First Observation of CERN and Fondue

2009-03-31T15:40:00.064+01:00

Hi, It's been suggested that I write a blog about my first trip to CERN and my first taste of fondue (actually it is because otherwise Patrick Koppenburg et al threatened to hold us hostage in a US army base "somewhere in Cuba" whilst forcing us to listen to David Gray's Babylon at full volume in an sensory deprivation cell - http://news.bbc.co.uk/1/hi/entertainment/7488498.stm). So here goes...

I Arrived on 15th March with fellow first year PhD student Paul (aka The Machine) Schaack for a software and Flavour Physics week for LHCb. The view from the plane of the mountains and stuff was cool, but don't arrive on an empty stomach to CERN on a Sunday night! Monday was full of software lectures and got to meet the rest of the Imperial LHCb crew: Tom, Will, Fatima and Chris. They were very nice and helpful in showing us around during the week.

Tuesday night the crew (with addition of Ulrik, Patrick and others) took us out to Geneva for a meal at a Vietnamese restaurant (Kinh Do?) and a bar afterwards. The buses run precisely on time and the streets are eerily clean and quiet, quite a change from London.

Wednesday we had not much to do so we, along with our first year comrades on CMS (Mike, Zoe and Robin), went to Geneva again to check out our future accommodation and had dinner at an Italian restaurant. Oh yeah, during the day we were fortunate enough to see the LHCb detector, which is situated 100m underground. It was big.

Thursday, fondue day. Went again to Geneva with the LHCb crew to a fondue place recommended by Patrick's mother-in-law. The place and the waiters were typically "Swiss-French", but the fondue was an experience... The taste was good but it was seriously filling(!) Luckily we received a health and safety introduction on how to eat fondue by Patrick before the meal and so we safely avoided the dangers of eating fondue... Still had room for an awesome dessert though (there's always room!).

Seeing as in a month or so's time we will be moving there for a long term attachment it was helpful to have had a taster of CERN and Geneva. Personally the place will take some getting used to: the food, the language, the orderliness, the sheer number density of beards at CERN, etc.. but also the prospect of living in a different country, winter skiing and stuff will be great. I am looking forward to it either ways.

Peace out,
Ravi & Paul

Ten Days of Neutrino Interactions in the Polish Countryside.

2009-02-20T13:27:00.012Z

My journey started in the early hours of a cold Sunday morning on the 1st February as I made my way to Stanstead airport for my 6 am flight. I was bound for Wroclaw international airport in the south east region of Poland and I was on my way to the 45th Karpacz Winter School organised by the university of Wroclaw. I had left in the nick of time (depending on your perspective) as the next day the UK was enveloped in the biggest snow storm in 18 years and many flights were canceled. This year the focus of the school was the modeling of neutrino interactions, an elusive type of particle with almost no mass and which only interact through the weak force.

Before I talk about the school and the wonders of Poland (Including lots of physics, lots of snow, some caves, and maybe even a wolf!) I should provide some background as to why I was there. I am a second year PhD student on the T2K long baseline neutrino oscillation experiment, I will skip the summary of the experiment as there are a numerous blogs that have already done this. The modeling of neutrino interactions, in particular with large composite objects like nuclei, is highly relevant for T2K and
other neutrino experiments as the only way to detect a neutrino is via its interaction with a nucleus present in the large detectors built to capture them. In order to make the kind of precision measurements that T2K aims to make it is necessary to know the energy and type of neutrino that has interacted within your detector and, as I found out, getting this right is very dependent on the models you choose to describe the interaction. It is this driving force from the new era of high precision measurements that has caused renewed interest in the field of neutrino interactions.

The aim of the school was to provide lectures on the current and future developments for the theoretical models that describe neutrino interactions alongside the approximations adopted in the various Monte Carlo generators. The Monte Carlo generators are the computer simulations that start the process of taking these theoretical models and making predictions about what will be seen in the experiment. There was also an emphasis on the current experimental activity in neutrino physics, many of these lectures (very good and useful - I would recommend them to any new students on T2K) were given by our very own Dr Morgan Wascko. For me this highlights the best part of the school which was that there was a healthy mix of theorists and experimentalists. Over the 10 days I feel there was a lot of constructive communication and clarification of ideas and requirements between the two groups.

The school lasted for six days and was followed by a three day workshop. The schedule was intense. Days were divided between lectures, theory exercises, Monte Carlo generator workshops, more lectures, and not to forget breaks in which people could explore the local countryside or go skiing. We started at 8.45 am and on many occasions people were still working at 10 or 11 in the evening.

There were many other things to do alongside the Physics. On the Sunday between the school and the workshop a trip was organised to go by coach to the Czech Republic to visit some famous caves in the Moravsky Kras region. They were limestone caves and were famous for the interesting shapes cut into the rock by the many thousands of years of water erosion (not actually erosion as they were limestone so the water dissolves the rock). I have uploaded a picture of the magnificent stalactites and stalagmites that surrounded us in the caves.

Unfortunately I was unable to go on the skiing trips due to a lack of equipment (I am quite tall and they only had little ski boots) and so I was forced to find other ways to explore the local surroundings. On one occasion me and a fellow T2K student went on an expedition up a local mountain (a hill technically but a very steep one at that). It had just snowed fairly heavily and the slope was very steep and slippery. It took us about half an hour to get to the top and on our way up we kept seeing similar sets of tracks in the otherwise undisturbed snow. The hill was wooded but at the top opened up into a very beautiful space bordered by woods. We kept seeing more of the tracks which were all headed to one part of the woods and managed to convince ourselves that they must be wolf tracks (This was for a number of reasons: 1 - There are wolves in Poland. 2 - The tracks implied a large animal with padded and clawed feel. 3 - It was snowing and we were in the woods. 4 - I have an abject fear of wolves). On our return down the hill we couldn't quite shake the feeling that we were being watched! See the image of the tracks on the right.

All in all I had a very productive and enjoyable time at the school and am very grateful to the organisers of the school who provided me with a grant that allowed me to attend.

A Happy New Year from Imperial T2K....

2009-01-27T12:50:00.004Z

A seriously-belated Happy New Year to all avid followers of this blog from around the world!

2009 will be a very big year for many of us at Imperial High Energy Physics, most certainly including me and my colleagues who are working on the T2K Experiment.

I am writing this as the names of some towns such as Petrozavodsk have finally started appearing on the in-flight map after several hours of unmarked Arctic coastline. Being on a certain cash-strapped flag-carrying airline has meant that there was no functional personal entertainment system to distract me from map-gazing and some slightly more fun duties such as marking student reports.

So here we are flying back from a week of meetings at KEK, the Japanese national laboratory for particle physics, where each day was filled with over 12 lovely hours of non-stop sessions of presentations and discussion.

After several years of work, this year our experiment will finally see data from actual neutrinos flying 200 miles across Japan from the village of Tokai on the eastern coast, to Kamioka in the hills in the north-west of the country. Our physicist colleagues at the new accelerator complex of J-PARC are working hard to make sure that we get lots of neutrinos making this journey, because by the very nature of neutrinos, we will only be able to observe a tiny fraction of them in our detectors.

The neutrinos will be made by slamming an extremely intense beam of protons into a long rod of graphite, where "strong" interactions (in the particle physics sense) will produce a huge shower of light particles, which produce neutrinos as by-products as they undergo "weak" interactions while flying down a 100m-long tube. Everything from the source of the protons, to the initial straight accelerator which gets them moving as a beam, the smallish synchrotron ring that raises their energy to 3 GeV, and the mile-long 50 GeV Main Ring which follows, is all brand-new, and over the last year or so, each component has been commissioned and tested, and the protons have gradually crept closer to the dedicated neutrino beam line for T2K.

The picture at the top is the place where the graphite target goes, as of a week or two ago.

The energy of the protons is tiny compared to those in the LHC (a GeV is one-7000th of the LHC energy of 7 TeV), which will also be turning on this year, but the power of the beam is what matters most for us, and will be the highest ever for an accelerator like this, fingers crossed!

With the recent successful commissioning of the Main Ring at 30 GeV, the neutrino beamline is all that is left now, and almost all the components are in place for the superconducting magnets and array of beam monitors to be switched on in a couple of months' time, and protons fired into the graphite target. Eventually, the accelerator complex will try and put as much power into the beam as possible, to make as many neutrinos as we can, but initially it will only be configured to produce a little beam, so that things can be checked out and everyone is certain they are happy that we can start cranking the power up later this year.

The beam is of course not the only critical part of T2K, and many things have to come together for the experiment to work: a host of detectors which make sure the neutrino beam is how we want it to be and is pointing in exactly the right direction; the ND280 "near detectors", 280m away from the target, which we are working on in the UK, and which will look at the neutrino interactions in unprecedented detail so that we can understand the beam properly and correctly interpret what the neutrinos are telling us; Super-Kamiokande, the underground tank with 50,000 tonnes of water that will detect the neutrinos after their trip across the country. There is even an experiment at CERN, called NA61, which putting in time to measure exactly what happens when you fire a proton beam at the T2K graphite target. This is actually very subtle physics that no one is able to calculate with any confidence, and hence measuring this will be a big contribution to T2K.

Each of these parts of the experiment is making very rapid progress, which we confirmed over the course of the past week, and we talked things over to make sure that everything will work well when it all comes together over the next year or so.

For ND280, we are now running tests at Rutherford Lab in Oxfordshire, to make sure that the detectors we are building, called electromagnetic calorimeters, work properly, and also the electronics and data acquisition systems that are UK responsibilities too. These will need to operate reliably with many of the other detector systems being built by our T2K friends around the world, so we have to make sure everything works before it is sent to Japan to be put underground in the ND280 detector cavern.

Of course we don't just build an experiment and switch it on and then wait to see what happens -- it takes a lot of work to figure out how best to use information we see in the detectors, and we need to make sure we know what to do with it beforehand. Much of my work is centred on ensuring that once the experiment is turned on, we know that it is working properly, that we can extract from the data everything we need, and that we can analyse that information and turn it into physics measurements that we can publish. This involves a lot of software work and physics analysis studies, which is the most exciting bit for me. Our 2nd year students gave presentations to the entire collaboration on their work, and personally I thought they did rather well.

On top of all this physics to discuss, there is a host of logistical issues that we also have to sort out, such as when and how we send our detectors, and who with, and how many people we need at J-PARC and when, how many physicists will fit into a cheap flat in Tokai etc....

This meeting at KEK was a target for a lot of the work we have been doing over the last several months, but it wasn't the first set of hardcore meetings this year. In November, I suggested that we have a T2KUK Physics and Software meeting before the start of term in January. Somehow, this idea proved surprisingly popular, and the meeting grew to a full UK collaboration meeting, which our friends at Liverpool kindly hosted.

Sometimes we complain about how we get overloaded by meeting after meeting, but I think these big occasions when we get a large number of people together in the same room, are impossible to do without. It is not just the slide presentations and formal discussions, but the informal chats over coffee that can really help brings ideas together and new things get started.

Once we get back from a meeting like this, it is back to the rather more laborious daily routine of getting things to work, fixing them if they don't, coming up with new things to try, and in general trying to meet deadlines, half of them self-imposed. I hasten to add that a large fraction of the actual contributions come from our students, which is always very rewarding for us as well as the students themselves (I think).

Other things that happened while we were away in Japan include: a lovely sunny afternoon when the weather on my balcony reached 24C; about 7 different types of ramen noodles; a mysterious "frying thing of fish" for lunch at the KEK canteen; lots of "Rilakkumas"; snow at KEK; the party on the Friday night followed by the traditional karaoke which Dave finally came along to; my team losing 4 - 3 in the Cup....

Well, we are over Krakow now, and I think I should take a little nap before we land. Now that everyone who reads this blog is probably all T2K'd out, I'll refrain from writing about our experiment till our next major development -- which may not be too far off!

Postgraduate Open Day Wednesday 21st

2009-01-13T12:56:00.004Z

Next week, we are inviting any potential postgraduate applicants to the group, to see for themselves what it is like to work and study here at Imperial High Energy Physics. You can find details of the Open Day and postgraduate opportunities on our web site, including who to email (Dr Ulrik Egede of LHCb, and postgraduate admissions committee chair) to ensure that you get your free lunch.

We've got various activities lined up for participants, which should be entertaining, so if you think you might like to join us here and work towards a PhD, and make friends with the ducks at Kensington Gardens, just let us know and come along on the 21st!

I wish I could be there myself to say hello, but unfortunately I will be at the KEK laboratory in Japan next week....

The LHC inaugration and the LHCFest

2008-10-22T17:23:00.010+01:00

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!

2008-10-09T11:11:00.012+01:00

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?

2008-09-28T17:37:00.004+01:00

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

2008-09-13T17:12:00.001+01:00

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

2008-09-11T16:16:00.006+01:00

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

2008-09-04T21:57:00.011+01:00

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.)