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Paul Jackson | CERN | Switzerland

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Wrapping it up with psychedelic photography

Friday, August 21st, 2009

So as Frank already posted we had a nice dinner as an early finale to the Lepton Photon conference. Good food, conversation and an almost constant flow of wine made for an enjoyable evening. As did the impeccable organization of our Hamburg hosts. The conference has been expertly run and everything has been planned and thought out down to the finest of details.

Post conference dinner where abstract lighting is crucial to mask reality.

post conference dinner where abstract lighting is crucial to mask reality.

I have been lucky enough to use this week to get back into work after my holidays and although I’ve been at all of the conference talks and absorbed some interesting and useful physics I don’t really feel like it’s been hard work at all. Of course I’ve had the privilege of meeting current (Ingrid and Frank), and some recently retired (Robert and Tony) Quantum Diaries members.

It’s funny to ‘know’ someone by sight without ever having met and to have something in common prior to having spoken a word. We’ll have to see how many future Quantum Diaries conference photos we can make!

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Lepton Photon 2009 begins

Monday, August 17th, 2009

Seems shameful to post a bit of quantum diatribe about how the Lepton Photon 2009 symposium has started
in Hamburg when Frank already did it earlier today but here goes anyway. You can find the slides and information
on the agenda here.
It is usually one of the best attended conferences in the field and, I would say unusually, it is all plenary talks,
meaning there are no overlapping sessions where you have to make the tough decision between seeing one talk or
another. It also makes for a relaxed atmosphere (with plenty of time to catch up with colleagues) and means that
most of the talks are summaries. One other obvious point to make is that unlike many other conferences the
majority of people attending will not actually be presenting a talk. This changes things. It means the audience
aren’t sat behind their laptops frantically trying to finish their own work and are actually listening to the information
being presented.

The stage is set at LP09

The stage is set at LP09

I’m sure one of the Quantum Diary attendees will fill you in on the results and details being presented during the week.

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Lunch Anyone?

Saturday, July 25th, 2009

There are a number of important aspects to the working day at CERN, the multitude of meetings,
the countless coffees, the time management in order to remain productive, but there is one chief
aspect of daily life for any CERNois: lunch!
Why is lunch so important to those at CERN you may wonder. It is quite simply that occasionally,
it is a fight for ones life to get some space in the cafeterias. Let me step back for a moment and
flesh this out with a few details. The Meyrin site at CERN has two restaurants, let
us call them ‘Restaurant 1’ and ‘Restaurant 2’ for no other reason than that is what they are called.
There is a third eating place (go on have a guess…that’s right ‘Restaurant 3’) on the Prevessin site
in France. As far as any general cafeteria food goes one must give credit to the CERN cafeterias,
there is ample choice and many healthy options, plus some unhealthy ones, but in the world of
Particle Physics cafeterias CERN is high up the list (Burrito day at SLAC is still Wednesdays I
believe for anyone heading out that way). The reason why lunch can become such a brawl centres
around the spikes of activity which CERN undergoes at certain weeks of the year. Imagine an
already busy eating place between 12 noon and 1.30pm. Not enough seats for all the patrons, long
lines and some quite aggressive customers (not a bad word to be said about the staff from me as
they are always top drawer). Now, add to that 500+ additional people visiting for a meeting for an
entire week. All of them eat lunch in the same cafeteria and all of them want lunch at exactly the same
time, usually when a talk or meeting session has ended. Of this quantum of physicists (not sure if that’s
the technical term but it has a certain ring!) most of them are carrying a bag of some sort as they
try to wade through the munching minions to get at the much desired foodstuffs.

anyone interested in a spot of lunch?

anyone interested in a spot of lunch?

For CERN this has been discussed all the way up to the highest level of management and it would
be naive for a simple user of the lab to call this a problem. It’s not really. During many weeks of the
year the restaurants aren’t even that full, rarely, does restaurant 2 have a more patrons than they can
handle, and it’s a pleasant environment to eat in. One thing that CERN does wrestle with though is the
problem of infrastructure that the eating issue highlights. As all of high energy physics converges
towards one lab, the number of users has grown faster than the additional office space, the working
areas and conference rooms, and the restaurant space. These issues take time to solve and CERN
reacts well to problems from my experience thus far so we will see how things evolve over time.
For now though we will train our eyes to spot an elusive table on the R1 patio, and try not to trip over
stray bits of debris while sprinting, with tray in hand, to secure it.

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The Auld Enemy

Tuesday, July 21st, 2009

Competition is a common thing in High Energy Physics. Whether it be between two individuals, working groups or
full collaborations, competing for money, time and prestige, we tend to measure ourselves against others and be
spurred on to try and beat someone else to the punch.

Visiting CMS. Your humble narrator (left), with unidentified ginger man.

Visiting CMS. Your humble narrator (left), with unidentified ginger man.

As you are likely aware, the LHC is home to two large multi-purpose experiments, ATLAS and CMS, with LHCb and Alice the two other experiments with slightly more specific charges. It is almost natural therefore that ATLAS and CMS are in competition. Currently, before data taking has begun, it remains a healthy rivalry, but once the gun is fired and we are (hopefully) inundated with stable beams from the LHC the gloves may, proverbially, come off. Competition will exist throughout the whole lifetime of these huge collaborations, but it is down to the physicists, and management, to keep it healthy. What helps keep this spirit alive is the friendships developed across the collaborations, after all, no-one is going to fight a friend are they!! As far as I’m concerned competition merely represents a challenge to improves ones own work and ensure you are doing the best science you can be and, as long as this remains friendly, then it remains healthy, and the research is the winner. In recent times CDF and D0, and BaBar and Belle (or going back to the LEP days and further still!), have inspired each other to make the most out of the data they collected in order to produce competitive results whereas, without each other it is likely the data may not have been mined so intensively and successfully as they were. This can be seen at the LHC already. With the startup operating energy lowered from the design energy of 14TeV, and a likely reduced intensity to begin with as the LHC team get to grips with operating their complicated machinery, physics analysts and detector performance experts are forced to be cleverer in order to optimize their work and invent new ways to understand the physics produced in their detectors. It is a fascinating time and the added challenge of producing measurements with very low luminosities is clearly spurring on the teams at both ATLAS and CMS (this is surely true at the other experiments also, whom I must not neglect so freely!).

CMS, ready for beam!

CMS, ready for beam!


I am a member of the ATLAS collaboration, having first started working on the experiment in 2004 and have remained active, with a brief hiatus, until the present day. Recently though, I had the opportunity, thanks to a friend of mine, to be shown around the CMS detector and so I jumped at the chance. It was, unsurprisingly, impressive to look around the detector and control room of CMS. As the engineers are frantically running around below, group after group of observers come in to get a peek of the detector and try to dodge the film crews and spanner wielding crew members. The sight of these monumental apparatus striking and with each detector I see I am always struck with a similar thought: how can that possibly work! It’s probably a bit skeptical to think this way, but it is more a reflection of the awe with which such human endeavors are held for me, than a cynicism about the detector, staff or project management themselves.

Benefiting from a knowledgeable tour guide helps (thanks Matt!) and I got a few pointers regarding the layout of the experiment and some great pictures of the detector to boot. I felt slightly guilty for missing a couple of hours of work at first but soon realized that this was a much better use of my time than trying to debug my latest piece of C++. There was an obvious lesson in it for me, one I learned many years ago but I would say comes and goes from the forefront of my working mind: get to know your detector! Not that you need to buy her flowers or take her out for ice-cream, but more understand what makes her tick, what she is (and isn’t) good at, and how you can help her be at her best, even when, like the rest of us, her performance starts to degrade with age. The more you know about the experiments you work on, the more you will be humbled by their complexities, challenged by their abilities and, ultimately we hope, excited by their results.

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ATLAS week

Monday, July 6th, 2009
ATLAS.....behind that big wooden ball!

ATLAS.....behind that big wooden ball!

The masses have gathered, one and all, once again here at CERN for
the second ATLAS week of 2009. LHC start-up strategy features high on the agenda, along with
impressive updates regarding the detector status and plans to have us prepared for first LHC
beams later this year. It’s always a busy time and with this meeting coming in the summertime
where more faculty and students have time away from class to attend the number of participants is
likely a bit higher than usual.

If you are resident at CERN, as I am, it’s not perhaps as useful as it is for those collaborators
coming from further afield to get their ATLAS fix. A lot of the information is available during
the slew of regular meetings and so the overview week is a good time to take stock and see
where work is heading. From my own perspective things are getting excitingly busy. The calibration
of the pixel detector is coming along well, and the software I’m putting together to make this global
task more manageable for people is starting to take real, and useful, shape. I’m planning to
start ramping to take many more shifts over the coming months, with some extra training still to do,
I should be useful in the control room before too long. Other than that I’m making good progress on
analysis activities and work on the upgrade. But this is a time to touch base with far away collaborators
and continue in person the work we often do remotely. The ‘weeks’ do provide a good time for
reflection, but also a time for focus. With such a large collaboration and mandate it is hard sometimes to
keep track of the global picture of the experiment and the achievements that are made on a daily basis.
We are increasing the efficiency of the detector little by little, have completed another combined run
to collect and analyse Cosmic Rays (many millions were taken) and we are testing new procedures
and systems which the run coordination and management team want in place before we get things going ‘for
real’.

It’s exciting. We get to see collaborators, many of whom are old friends, arrange BBQs (the ‘ATLAS run BBQ’ is on
Tuesday) and find out how everyones work is coming along. Much of this can come at the expensive of ones
own progress throughout that particular week, but this a small price to pay. It’s important to have your fingers on the
pulse of “your” experiment and to know the activities and the players involved in making it all work.

For ATLAS collaborators coming to CERN from out of town: Welcome, and enjoy the meeting!!

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Packed House

Thursday, July 2nd, 2009

Several hundred CERN residents crammed themselves into the Main auditorium this warm and sunny afternoon for
an update on the LHC schedule, and what turned out to be a free sauna.

The Director General (often referred to, in the spirit for acronym adulation, as the DG) gave a brief summary on the
details of the CERN Council meeting. For those of you who are not aware what this is (I rank amongst you but
I’ll give a summary of my understanding) it entails a select group of individuals representing the member states and
prominent physicists who, in essence, decide on the direction of CERN. The DG mentioned many things, one which
I picked up on was the applications from Cyprus, Serbia, Turkey, Israel to become new member states. There was
a 5th letter of intent to apply from Slovenia. The discussion of the ratification of the five applications was postponed
until December, at which time it sounds like all of them applicants will be given the green light. It sounds like the
council week, which just occurred, was rife with lots of discussion and planning.

The DG’s talk was essentially a teaser for the main event of the afternoon which was CERN accelerator physicist
Steve Myers giving a summary of the LHC schedule and an update on the repair status and current plans. The talk
was extremely detailed and his usual blend of jovial discussion with accurate description of complex problems such
that practically the entire audience could grasp at least the gist of the slides. The talk consisted of 122 slides which
Myers described as having been, “cut it down by a factor of 2 this morning.” It covered a few topics, chief amongst
them being the LHC shutdown work, splice measurement, powering and tunnel access restrictions and, the one that
most of the crowd had gathered for, the LHC schedule and strategy. You can catch the live webcast here, or if you have the access the video is in CDS here.

The bottom line I would say is good news, compared to many rumors which have been flying around the place
in recent weeks. There are repairs to be made and they will not know the outcome of these tests on all sectors
until early August but the schedule will only slip by a matter of weeks and not months.

There was one thing noticeably missing from Myers’ presentation though: dates. The reason is that they just
cannot predict the results of the further tests required on the potentially errant connections in the sectors
still under test and so, before calling the worlds press to CERN again, they seem to be taking a more cautious
approach. A wise move I would say.

Still, the news looks promising for collisions in the LHC later this year and all that can be said is,
we’ll keep you posted.

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Going Public

Friday, June 19th, 2009

Congratulations to Nicole for her first publication on SPIRES. It got me thinking about
publications in high energy particle physics a bit and how the large collaboration represents a
blessing and a curse to this. As a former member of the BaBar collaboration I can take a look
on SPIRES and see hundreds of papers that I have authored. If I am being brutally honest
though, many of these I have never read, and some of them, I may not even fully understand.

These days, working on ATLAS, I suppose I could rub my hands with glee and look forward to
the monumental number of papers my name may be included on in the coming years. But how
does this huge number of papers that we author affect our careers. When there are applications
for funding or fellowships for graduate students and postdocs that are extremely competitive
we are asked to highlight our own individual contributions. In other fields this is clear, you
show your list of publications where you may have 5,10,20 or so papers with your advisor or
collaborators who number in the handful. For us high energy physicists this is harder, giving a
list of 200 papers may seems like a great thing on the face of it, but this in no way highlights
ones own contribution to the experiment and therefore to the field at large.

Within high energy physics people know the score. You apply for a job with a list of papers you
actually worked on and that, without you, they maybe would never have
even seen the light of day. This is sort of an unwritten rule. But when the criteria explicitly ask for
a list of all publications, you chop down a couple of trees, and print out what they asked for.

This is a potential problem that cannot be easily solved. Each major collaboration over the last 10
years, along with current and future projects have discussed the issue at length, and I certainly
have no answer herein. Credit where credit’s due, is a tough concept to impose in high energy
physics. If one physicist does an analysis of the data does that mean they are more deserving
of the publication than the engineer who built and calibrated the subdetector that was crucial to
their work? No. Of course not.

Gone are the days when a few men, wearing suits and glass, put together accelerators and
detectors and published their findings together. We have a duty to do our ‘big science’, but we
have to realign old misconceptions about what it means for us as individuals to publish our
results.

In other news: Welcome to our new set of Quantum Diarists!

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Violating SUSY

Wednesday, June 10th, 2009

It can be minimal, while also unconstrained, split and violated. ‘It’ is, of course, SUSY.

I was flicking through some of the talks in the schedule of the SUSY 09 conference being held
in Boston, Ma this week, and learning a number of interesting things along the way. In my opinion ‘learning
interesting things’ is a good thing to get from any conference and can fuel your own imagination
for future work. So it was in this state of learning I studied the slides covering a vast spectrum of
potential ways to hint at, or direct methods to discover, supersymmetry.

It reminded me of a story from a workshop I attended when I was a young, wet-behind-the-ears graduate student. Two distinguished gentlemen physicists were in the queue for coffee/beer/snacks or whatever it was, and were regaling stories of a recent meeting. One mentioned to the other about a mutual friend who he had happened to catch taking a cheeky nap during a talk on Supersymmetry. He then made his colleague enter into a fit of laughter when he continued that their friend was jolted awake by the speaker mentioning, at some point during the talk, that he was “violating SUSY”. The two senior scientist giggled like schoolboys at this and mused as to whether their colleague had “a past history with SUSY”, or had, “violated SUSY himself perhaps” and other such comments. It struck me at the time as a little childish, but the moment had a silly charm, in the same way any giggling pensioner does.

Fast forward a few years and SUSY is no laughing matter. It is the shining beacon of new physics discovery in the near future and the raison d’etre of the LHC physics program, along with ‘the Higgs thing’. SUSY is considered an eventuality, no longer an exotic possibility, the conundrum being how it will be discovered, not if. Supersymmetry does present a rich and elegant new physics tapestry by which many problems that we have with the current Standard Model can be neatly solved. To date, there is no hard evidence of the existence of any suspersymmetric particles. The lightest SUSY particle, since it need not decay, would provide a tempting, and in some theories quite elegant, solution to Dark Matter by being the candidate particle that makes up this large fraction of the matter of the Universe. But this can often be brought forth in an ad hoc let’s-kill-two-birds-with-one-stone type of way. What I find most interesting as an experimentalist is that although SUSY has yet to be observed it is treated in a very different way to other potential new physics phenomena. In particular, people EXPECT SUSY to show up at the LHC. The “I told you so’s” will have to wait for the data to see whether this is the case.

Allow me to take a momentary aside at this point to bring those of you up to speed who have diligently read this far without the slightest notion of what it is I speak. SUSY is the abbreviated name for Supersymmetry, that provides a relation between elementary particles of one spin to another particle whose spin differs by half a unit; these are known as ‘superpartners’. In basic terms therefore, in a supersymmetric theory, for every type of fermion (like an electron from example) there exists a corresponding type of superpartner boson (selectron), and vice-versa. As the astute among you will have gathered this leads to roughly doubling the number of (fundamental) elementary particles, great news for experimentalists as it gives us all kinds of new things to look for.

If (some would say when) supersymmetry is discovered it will be a major achievement for high energy physics and usher in a whole new era of measurements that will profoundly alter the ways in which we view the Universe and the spectrum of it’s constituent fundamental particles. On the other hand, should we manage to rule out some regions of the SUSY parameter space (we can’t completely rule out SUSY as a possibility but can say that certain aspects of it are very unlikely) this could point to a completely different way, perhaps not yet considered, in which the various things SUSY provides can be manifested without recourse to doubling the particle count.

For those eager to learn more, an excellent source of information about the subject can be found in Stephen Martin’s ‘Primer’ on the subject here.

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A starting point

Friday, June 5th, 2009

I suppose it would be fair to say that I have mused long and hard about what to put in this, my first blog posting
for Quantum Diaries. It seems the norm is to go for the mixture between Oscar acceptance speech (“It’s an honour
and privilege to receive this opportunity etc etc”) and extended biography (“I was born in a small village and started
to study physics from the age of two in my father’s woodshed etc etc”).  This is not to knock my now fellow Diarists, on the contrary, it is more to make the point that it is hard to gauge what readers of this particular blog would care to see. Given that I am blind, in a sense, to the audience there is no clear beginning to the message. Hopefully over the coming weeks and months my experience with this interface to the world will develop and I’ll be able to give a reader friendly, perhaps even mildly entertaining, expose on life at CERN, as a physicist working on the LHC, and various ways in which this broadens and impacts ones life. However, until such glorious moments arrive, I will sit here struggling for a suitable opening message.

Well let’s see, what do I plan to include in this blog? To begin with I imagine a few stories and anecdotes to appear in due time. I work for SLAC, in Stanford, California, although I’m not American, and am based at CERN full time.  The astute among you will have spotted the “u” I strategically placed in the spelling of “honour”, the telltale sign of my Britishness (Englishness in my particular case). Coupled with working for one laboratory while being based at a different one, I experience the added complication of living and working in different countries: France and Switzerland in my case. If it sounds confusing, that’s because it is, although my case is not an uncommon one for CERN residents. Certain nuances like this add to the diversity and richness of the experience of working at CERN. From many points of view other than simply a scientific one CERN is a fascinating place, whether one cases the joint anthropologically, socially, or from the standpoint of work ethics (many researchers here tend to put in long hours) the molds are generally at the very least bent, in the majority of cases broken and for some outliers the molds are reinvented. I will not spoil this random introduction with a “for instance”, those will appear in due time, but there are a great number of things considered normal to a working physicist that most other people may think are just insane.

In these days where everyone knows what a Higgs boson is, and your bus driver or postman know more about the LHC schedule than you and your fellow physicists do (the LHC is moving closer to having first colliding beams with repairs progressing smoothly), high energy physics isn’t on the fringes of society anymore. Sites such as interactions.org and symmetrymagazine.org provide accessible high energy physics information to the reasonably informed, but not necessarily expert, reader. Particle Physics is the new hot topic at the movies or on television and everyone is scrambling it seems to include any kind of geeky-physics-nerd-type character into whatever they can. This is a good thing for the field, inspiring the minions of future discoveries and new underground particle revolutionaries by exposing them to the particle zoo at an early age. But also, perhaps, it impacts the ways in which we wish to put across a message of science and ‘life at the labs’ to a broader community. Through these blogs we can let people know of the realities of life as a physicist and not just the broader picture of the questions that the field is trying to answer. Perhaps though, the latter is a bit more exciting to read about than the former, although that depends on the life of the physicist in question!

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