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Archive for March, 2011

Flyer calling for power saving

Almost three weeks after the Tohoku earthquake and tsunami, daily life at IPMU is slowly returning to normality.

The first week after the earthquake, operations at IPMU were hampered by almost daily power cuts lasting for several hours. Luckily, the Kashiwa Campus has now been exempt from the rolling blackouts, and also the trains servicing the nearby stations are back to a regular schedule. While power conservation measures are still in effect (and will be for some time to come), they are at worst minor inconveniences. They mostly take the form of less lighting, less heating, less elevators and escalators running, and trains operating at a slightly reduced schedule. Compared to what the people in the disaster-hit areas are going through, Greater Tokyo is really well off and it would be inappropriate to complain.

Setsuden! (Electricity saving)

Unfortunately, the international media have passed around a lot of misinformation and have been hard at work to create a lot of hysteria surrounding what they call the ongoing “nuclear disaster”. Consequently some IPMU members, mostly yielding to pressure from their families abroad, have left the country. Understandably, also many foreign visitors have canceled their trips to IPMU and seminar schedules have been swept clean.
From my point of view, the tone of international reporting about the problems at the Fukushima power plant has been regrettable, bordering on irresponsible, and has done a great disservice to everyone who is living in the region and is being affected by the events.
Given that Greater Tokyo has not suffered much damage in the quake and that the problems at Fukushima Daiichi have never given rise to health concerns for people in the Greater Tokyo region, it is high time for us to resume our daily life. Every day, our tea time attracts more people again and IPMU is working to restart a regular schedule of seminars and group meetings again. As scientists, we must stick to the facts and avoid succumbing to irrational fears.


As an undergraduate physics major, I was introduced to the Heisenberg uncertainty principle, which states that it is impossible to measure the exact momentum and position of an object at the same time.  This is not caused by inadequacies in our experiments.  Instead, it implies a fundamental limit to our ability to predict the future of a system because we cannot precisely determine its present state.  Such a conclusion is shocking to any physicist. Even Einstein himself refused to accept it.  

Visible matter accounts for only 5 percent of the universe. CDMS hopes to identify the dark matter contained in the remainder of the universe. Courtesy: SLAC/Nicolle Rager

Shocking as the principle is, my university education at least prepared me for the uncertainty of the subatomic world.  What I wasn’t taught was how much uncertainty is embedded in the day-to-day life of a physicist.   A little over a week ago, the mine where my experiment is housed experienced a fire.  The name of my experiment is the Cryogenic Dark Matter Search, or CDMS.  

Before I tell you about the fire, let me explain the purpose of CDMS. Scientists have gathered a large body of evidence that tells us most of the matter in the universe is not in a form that we can see.   Matter that we can see takes on the form of stars, planets, moons, comets, interstellar dust etc..  Dark matter is instead composed of a form of matter that we have never observed on Earth.  My experiment is attempting to probe this dark matter component of the universe and will help us understand what  dark matter is really made of.  CDMS is located approximately 1 km, or a little more than half a mile, underground inside the Soudan Underground Laboratory – up near the Boundary Waters of northern Minnesota.  This unusual location allows us to use the earth as a barrier to cosmic rays.  These can produce signals that  will confuse our attempts to observe dark matter.

The CDMS with sheilding surrounding the silver cryostat where the detectors are housed. Credit: Fermilab

So while housing the experiment deep underground is necessary for its function, it can make for some unexpected challenges. The day of the fire, I and my colleagues waited anxiously, hour-by-hour for the latest news on the attempts to extinguish it.  Luckily, the fire was not in the lab, but was instead in the mine shaft.  Since this shaft serves as the entry and exit to the laboratory, it was still quite a serious situation.  In the end, the fire was put out after heroic efforts on the part of the Minnesota Department of Natural Resources, which operates the laboratory, and the various emergency responders.  Thankfully no one was injured and the damage to the mine shaft and infrastructure were minimal compared to our initial fears.  Since last week, the laboratory staff has been busy restoring power to the underground lab and assessing damage to the mine infrastructure.   As of this Monday, a few scientists have finally been allowed restricted access to the lab.  They are  beginning to assess the status of CDMS.

Before the fire broke out, we were in the midst of an engineering run.  The purpose of this run was to commission a new design for our detectors.   We were very excited about the results of this run because they would demonstrate the power of the new detector design.  This is a necessary step towards convincing our funding agencies that we are ready for the next step of building a much bigger experiment.   Now everything has come to a screeching halt as we continue to wait to find out when we will be able to resume our work. 

 Even without the drama of the mine fire, these past few weeks are a very tense time for a postdoc, such as myself, who is in the process of applying for faculty positions.   I was one of the lucky few this year who was able to land several interviews at top universities.   These interviews are grueling sessions where one must meet and talk to many people over the course of a few days.  During a packed series of 30-45 minute interviews, where one often doesn’t even get a few minutes break in between sessions, you must simultaneously explain your research and try to find out as much about the university as possible. 

The interview rounds are largely finished for this year.  Now it is the time when the schools begin making offers to their first-choice candidates.  Some of these decisions will make or break the dreams of young physicists.  On the part of the universities, its a very large investment, especially because the recent downturn in the economy has prohibited many schools from making hires in the past few years.

 Anxiety runs high on all sides as I continue to wait for news of my future and that of CDMS…

–Lauren Hsu


A different presentation of the Higgs

There have been several very clever attempts to explain the Higgs to a general audience using analogies; one of my favorites is a CERN comic based on an explanation by David Miller. Science-by-analogy, however, is a notoriously delicate tightrope to traverse. Instead, we’ll take a different approach and jump straight into the physics. We can do this because we’ve already laid down the ground work to use Feynman diagrams to describe particle interactions.

In the next few posts we’ll proceed as we did with the other particles of the Standard Model and learn how to draw diagrams involving the Higgs. We’ll see what makes the Higgs special from the diagrammatic point of view, and then gradually unpack the deeper ideas associated with it. The approach will be idiosyncratic, but I think it is closer to the way particle physicists really think about some of the big ideas in our field.

This first post we’ll start very innocently. We’ll present simplified Feynman rules for the Higgs and then use them to discuss how we expect to produce the Higgs at the LHC. In follow-up posts we’ll refine our Feynman rules to learn more about the nature of mass and the phenomenon called electroweak symmetry breaking.

Feynman Rules (simplified)

First off, a dashed line represents the propagation of a Higgs boson:

You can already guess that there’s something different going on since we haven’t seen this kind of line before. Previously, we drew matter particles (fermions) as solid lines with arrows and force particles (gauge bosons) as wiggly lines. The Higgs is indeed a boson, but it’s different from the gauge bosons that we’ve already met: the photon, W, Z, and gluon. To understand this difference, let’s go into a little more depth on this:

  • Gauge bosons, things which mediate “fundamental” forces, carry angular momentum, or spin. Gauge bosons carry one unit of spin; roughly this means if you rotate a photon by 360 degrees, it returns to the same quantum mechanical state.
  • Fermions, matter particles, also carry angular momentum. However, unlike gauge bosons, they carry only half a unit of spin: you have to rotate an electron by 720 degrees to get the same quantum state. (Weird!)
  • The Higgs boson is a scalar boson, which means it has no spin. You can rotate it by any amount and it will be the same state. All scalar particles are bosons, but they don’t mediate “fundamental” forces in the way that gauge bosons do.

This notion of spin is completely quantum mechanical, and it is a theorem that any particle with whole number spin is a boson (“force particle”) and any particle with fractional spin is a fermion (“matter particle”). It’s not worth dwelling too much about what kind of ‘force’ the Higgs mediates—it turns out that there are much more interesting things afoot.

Now let’s ask how the Higgs interacts with other particles. There are two Feynman rules that we can write down right away:

Here we see that the Higgs can interact with either a pair of fermions or a pair of gauge bosons. This means, for example, that a Higgs can decay into an electron/positron pair (or, more likely, a quark/anti-quark pair). For reasons that will become clear later, let’s say that the Higgs can interact with any Standard Model particle with mass. Thus it does not interact with the photon or gluon, and for argument’s sake we can ignore the interaction with the neutrino.

The interaction with fermions is something that we’re used to: it looks just like every other fermion vertex we’ve written down: one fermion coming in, one fermion coming out, and some kind of boson. This reflects the conservation of fermion number. We’ll see later that because the Higgs is a scalar, there’s actually something sneaky happening here.

Finally, the Higgs also interacts with itself via a four-point interaction: (This is similar to the four-gluon vertex of QCD.)

There are actually lots of subtleties that we’ve not mentioned and a few more Feynman rules to throw in, but we’ll get to these in the next post when we will see what happens with the Higgs gets a “vacuum expectation value”. Please, no comments yet about how I’m totally missing the point… we’ll get to it all gradually, I promise.

Higgs Production

Thus far all we’ve been doing is laying the groundwork in preparation for a discussion of the neat things that make the Higgs special. Even before we get into that stuff, though, we can use what we’ve already learned to talk about how we hope to produce the Higgs at the LHC. This is an exercise in drawing Feynman diagrams. (Review the old Feynman diagram posts if necessary!)

The general problem is this: at the LHC, we’re smashing protons into one another. The protons are each made up of a goop of quarks, antiquarks, and gluons. This is important: the protons are more than just three quarks! As we mentioned before, protons are terribly non-perturbative objects. Virtual (anti-)quarks and gluons are being produced and reabsorbed all over the place. It turns out that the main processes that produce Higgs bosons from proton collisions comes from the interaction of these virtual particles!

One of the main “production channels” at the LHC is the following gluon fusion diagram:

This is kind of a funny diagram because there’s a closed loop in the middle. (This makes it a very quantum effect… and somewhat more tricky to actually calculate.) What’s happening is that a gluon from one proton and a gluon from the other proton interact to form a Higgs. However, because the gluons don’t directly interact with a Higgs, they have to do so through quarks. It turns out that the top quark—which is heaviest—has the strongest interaction with the Higgs, so the virtual quarks here are tops.

Another way to get a Higgs is associated production with a top pair. The diagram looks like this:

Here gluons again produce a Higgs through top quarks. This time, however, a top quark and an anti-top quark are also produced along with the Higgs. We can draw a similar diagram without the gluons:

This is called vector fusion, because virtual W or Z bosons produce a Higgs. Note that we have two quarks being produced as well.

Finally, there is associated production with a W or Z. As homework you can fill in the particle labels assuming the final gauge boson is either W or Z:

There are other ways of producing a Higgs out of a proton-proton collision, but these are the dominant processes. While we know a lot about the properties of a Standard Model Higgs, we still don’t know its mass. It turns out that the relative rates of these processes depends on the Higgs mass, as can be seen in the plot below (from the “Tevatron-for-LHC” report):

The horizontal axis is the hypothetical HIggs mass, while the vertical axis measure the cross section for Higgs production by the various labeled processes. For our purposes, the cross section is basically the rate at which these processes occur. (Experimentally, we know that a Standard Model Higgs should have a mass between about 115 GeV and 200 Gev.) We can see that the gg → h is the dominant production mechanism throughout the range of possible Higgs masses—but this is only half of the story.

We don’t actually directly measure the Higgs in our detectors because it decays into lighter Standard Model particles. The particular rate at which it decays to different final states (“branching ratios”) are plotted above, image from CDF. This means we have to tell our detectors to look for the decay products of the Higgs in addition to the extra stuff that comes out of producing the Higgs in the first place. For example, in associated production with a top pair, we have gg → tth. Each of the tops decay into a b quark, a lepton, and a neutrino (can you draw the diagram showing this?), while the Higgs also decays—say, into a pair of b quarks. (For now I’m not distinguishing quarks and anti-quarks.) This means that one channel we have to look for is the rather cumbersome decay,

gg → tth →blν blν bb

Not only is this a lot of junk to look for in the final state (each of the b quarks hadronizes into a jet), but there are all sorts of other Standard Model processes which give the same final state! Thus if we simply counted the number of “four jets, two leptons, and missing energy (neutrinos)” events, we wouldn’t only be counting Higgs production events, but also a bunch of other background events which have nothing to do with the Higgs. One has to predict the rate of these background events and subtract them from the experimental count. (Not to mention the task of dealing with experimental uncertainties and possible mis-measurements!)

The punchline is that it can be very tricky to search for the Higgs and that this search is very dependent on the Higgs mass. This is why we may have to wait a few years before the LHC has enough data to say something definitive about the Higgs boson. (I’ve been somewhat terse here, but my main point is to give a flavor of the Higgs search at the LHC rather than explain it in any detail.)

As a single concrete example, consider the gluon fusion production channel, gg → h. This seems nice since there’s no extra particles in the production process. However, from the plot above, we can see that for relatively light masses (less than 140 GeV) the Higgs will want to decay into b quarks. This is no good experimentally since the signal for this has hopelessly large background from non-Higgs events.

In fact, rather counter intuitively, that one of the best ways to use gluon-fusion to search for a light-mass Higgs is to look for instances where it decays into a pair of photons! This is really weird since the Higgs doesn’t interact directly with photons, so this process must occur through virtual quarks, just like the Higgs-gluon coupling above. As the branching ratio chart above shows, this is a very rare process: the Higgs doesn’t want to decay into photons very often. However, the upshot is that there aren’t many things in the Standard Model which can mimic this “two photon” signal so that there is very little background. You can see that this stops working if the Higgs is too heavy since the decay rate into photons shrinks very quickly.

Next time

In our next post we’ll introduce a completely new type of Feynman rule representing the Higgs “vacuum expectation value.” In doing so we’ll sort out what we really mean when we say that a particle has mass and continue our march towards the fascinating topic of electroweak symmetry breaking (“the Higgs mechanism”).


Thanks, Mr. Simons!

Thursday, March 24th, 2011

This week, I am attending the workshop “Branes and Bethe Ansatz in Supersymmetric Gauge Theories” at the brand-new Simons Center for Geometry and Physics in Stony Brook. While the theoretical physicists and mathematicians at the State University of New York in Stony Brook have been a force to be reckoned with for some time already, this new center came into being thanks to a large donation by Jim Simons. Simons, a successful mathematician (the one of Chern-Simons), had later in life made a fortune with his extremely successful hedge fund management company Renaissance Technologies, and he continues to support science generously. Upon entering the shiny new Simons Center, it becomes clear immediately that this is a well-funded place. We are fed breakfast, lunch cooked by an excellent chef in the center’s own cafe, and oven-fresh cookies during coffee break.
Scientifically, this workshop has been a success. Among many others, we’ve also had the chance to hear the talks of two Fields Medal winners.

Of course, nothing in life is free. I had to pay for all this by suffering through a 12+ hour flight and an 11 hour jet lag (the biggest I have come across so far).


Lecture on Fukushima radiation

Forgive me for digressing a bit from the LHC focus of this blog, but I wanted to take time to share a timely and accessible public lecture by UCSB particle physicist Benjamin Monreal about the science of the Fukushima reactor meltdowns in Japan. I strongly recommend it for those who want to be able to make sense of the news regarding radiation in Japan and elsewhere.

One of our jobs as scientists is to be there to inform the public when something like this happens, and Benjamin rises to the occasion with exceptional clarity. As he mentions towards the end of his talk, it is often the case that misinformation is one of the biggest dangers after an event like this, and he goes a long way to explain what’s actually going on. I learned quite a lot from the presentation and it has helped me provide a proper scientific context for the news about the region.

It’s always very difficult to cope with the aftermath of a natural disaster on the scale of the Tohoku earthquake two weeks ago. The particle physics community is especially international and the news of the disaster hit quite close to home for many of us with friends and colleagues in Japan. Our hearts go out to everyone affected.

Coleman’s QFT Lectures

Sidney Coleman. Image from L. Motl.

Now to change gears quite a bit, I’d like to share another link that has been making a splash in particle physics circles: a typed up version of Sidney Coleman’s 1985-1986 Physics 253a quantum field theory course at Harvard, thanks to the heroic typesetting efforts of Bryan Gin-ge Chen and Ting Yuan Sen. (See also the videos of the lectures from 1975-76.) The link is perhaps most useful for young physicists who are learning field theory (or older physicists who are teaching field theory), but as a concession for the non-physicists reading this blog, here’s a link to Coleman’s well known seminar, “Quantum Mechanics in your face.”

Let me provide some background. Sidney Coleman is one of the towering figures of theoretical physics in our time and one of the true masters of quantum field theory. While he doesn’t have the same popular image as Richard Feynman, his unique charm and wit as well as his dexterity as a teacher are nothing short of legendary in the physics community.

Coleman’s life and work were commemorated at Harvard in 2005 at “Sidneyfest.” The list of famous presenters and speakers speak volumes about Coleman’s influence. Sadly, Coleman passed away in 2007. He left behind an indelible mark on the history of quantum field theory as well as several lectures (most notably his Erice lectures, published in Aspects of Symmetry) which continue to educate generation after generation of particle physicists.


A good friend of mine, Brian Christian, has recently written a book and a teaser article in The Atlantic about Artificial Intelligence and what it can teach us about our humanity. As a physicist, I enjoy learning about AI and other broad technological advancements, and as a human, I enjoy learning and thinking about humankind; I find the intersection particularly intriguing.

Ken Jennings, 74-time Jeopardy champion, competing against IBM's Watson

At issue are the defining characteristics that make us uniquely human. Historically, we would compare and contrast ourselves with the rest of the animal kingdom. We would make statements like “Humans are the only animals that use tools” (a fine theory until primates were observed doing the same thing), or “Humans are the only animals to use language” (until discovery of communication in dolphins, whales, and other species). With the advent of computing and advances in AI and machine learning, the list of uniquely human attributes is dwindling rapidly. To start, computers possess memory and arithmetic skills that easily outclass humankind. Perhaps more interestingly, computers have demonstrated superiority in specialized fields like chess (Deep Blue) and Jeopardy (Watson), emerging victorious against the top human contenders – impressive feats given the non-deterministic trajectory of the contests.

So what about us is unique? Is it possible to complete the sentence “Humans are the only animal to __________”, in a way that is accurate now and reasonably accurate in the future? As I ponder this, I can identify two broad areas in which the quintessential essence of humanity shines through (and I’m sure there are many others that I haven’t considered).

The first is one of subtext – an ability to “read between the lines.” We can tell when someone is bored without asking directly. When a friend says “everything’s fine,” we can tell immediately if everything’s fine, or if there is some concealed crisis. Bribery, seduction, and threats (to use the words of Steven Pinker) can all have their desired effects without being spelled out explicitly. As humans, this comes so naturally to us that most people take it for granted.

Subtle body language, wordplay, and innuendo all stem from the root of shared experience. A human from a different culture may easily misinterpret or miss altogether these forms of under-the-radar communication. Having a computer attain fluency in such a medium seems to me reasonably out of reach for now. It’s worth noting that Watson performed most poorly when faced with questions involving puns, jokes, or words used in unusual contexts. Deep Blue played chess most weakly not during the opening (memorizable) or end-game (calculable), but the middle-game, where strategy, subtle positioning, possible gambits, and intent all need to be analyzed.

A second broad area that seems exclusively human is that of imagination and the will to create. The obvious application of imagination and creativity is to the arts; humans hold the monopoly on art for art’s sake, and computers have a long way to go to catch up. This may not be altogether unexpected. The arts are a subset of the humanities – those subjects which seek to inform us about the human condition. It is an enormous challenge for a computer, without any shared human experience, to teach us something about humanity. People certainly try; I like the example of a program that composes in the style of Bach. It can do pretty well for a short while, but then gets stuck in a rut – it fails to surprise us with new keys, transformations, and motives as would be expected from Bach. In a sense, these masters of high art – Bach, Shakespeare, Michelangelo – are guardians of our humanity, in that their creations stand alone as something only humanity can accomplish.

Of course, imagination and creativity are not limited to the arts. I would argue quite strongly that these concepts are of supreme value in the sciences, physics included. We may have ceded the grunt work of equation solving and data analysis to computers, but ideas are human borne. Einstein’s quote – that “imagination is more important than knowledge” – rings prescient here. The capacity of the human mind to see reality as it is, and imagine the unknown, underlying governing laws, seems safe from the encroachment of computers that necessarily rely upon pre-programmed, well-known governing laws.

I believe that identifying unique aspects of our humanity can have far-reaching implications, but I want to restrict myself to a quick discussion of education for now. In the US, modern schooling revolves around standardized testing, in which creativity is too often subordinate to fact memorization. This is troublesome in an era where we are losing (have already lost?) our knowledge supremacy to computers. It seems as though we should grab hold of creativity or whatever else makes us uniquely human, and build a culture around encouraging these pursuits. Otherwise, we may simply be leading future generations down a path of obsolescence.

Whatever the implications, thinking about the relationship of AI and our own humanity can teach us something new about ourselves, which in my mind makes it a fascinating subject.


Dim lecture halls: Nobu Toge giving an update of the situation at KEK in Japan.

My spring travel season is in full swing, and brings a lot of work with it: New results to finalize, talks to prepare and to give, discussions, … which means I’ve again been neglecting Quantum Diaries. I am in Eugene, Oregon at the moment, at the Linear Collider Workshop of the Americas. Things are now winding down, after almost five days packed with new results and intense discussions.

Of course one of the recurring themes were the LHC results which are now coming in, and which are starting to seriously eat into the space for models for new physics that could be explored at a new collider. The Higgs might be just around the corner, and other discoveries are hoped for. What that is… Who knows? It could be Supersymmetry, a number of other models floating around, or, perhaps most exciting, something completely unexpected. Needless to say, that would give the whole field a new push, and show us where to head with a new large scale experimental facility.

News from Japan are also omnipresent, with a large number of our colleagues from Japanese labs and universities absent for understandable reason. Just this morning, Nobu Toge gave a report from KEK, including a video shot in the accelerator test facility at KEK during the earthquake. That showed everyone once more what a powerful natural disaster has hit Japan less than two weeks ago. Damage to experimental facilities is still being assessed, but the really good news is that as far as we know now, none of our colleagues has suffered bodily harm.

The pacific coast, west of Eugene, Oregon, on a rainy Sunday morning.

Of course, five days in dim lecture halls without getting out at all is too much, so I took the opportunity to clear my head by visiting the stunningly beautiful pacific coast. Weather was not perfect, but nothing beats some fresh air. Right here in Eugene, there are first signs of spring, with flowers and trees in bloom, during a rare moment of sunshine. Today, the rain is back, with bad weather reported from San Francisco which has me worried about my connection for my trip back home tonight… Keep your fingers crossed, but then, there are worse places to get stranded than San Francisco…

Signs of sping in Eugene, Oregon.


Why run at lower energy?

Wednesday, March 23rd, 2011

Right now the LHC is about to start a short run with proton-proton collisions at a center of mass energy 2.76 TeV.  This is lower than what we ran last year and is a special request from the heavy ion physicists.  So you’ve heard a lot about why the particle physicists want to go to higher energy.  But why do we heavy ion physicists want to go to lower energy?

We want a reference for our lead-lead collisions.  If nucleus-nucleus collisions were nothing but a bunch of proton-proton collisions, what we measure in lead-lead collisions should be just some constant times what we measure in proton-proton collisions.  This is a bit simplistic, but it’s a pretty good start.  A lot of our measurements use proton-proton collisions as a reference and look for differences between proton-proton collisions and lead-lead collisions.  For instance, in the paper I discussed here we looked at the distribution of particles as a function of their momenta in lead-lead collisions and compared that to what we observed in proton-proton collisions.  For this paper we used the data from proton-proton collisions at 900 GeV and at 7 TeV to extrapolate to what we’d expect at 2.76 TeV, the same energy per nucleon as our lead-lead collisions.  As discussed here our models for proton-proton collisions are pretty good but they get some of the details wrong – and miss some features like this.   Since we depend on models to extrapolate to 2.76 TeV, we have greater uncertainty in our measurements than we would have if we had data at 2.76 TeV.  The LHC can go down to 2.76 TeV and what we need 2.76 TeV proton-proton data doesn’t require as many statistics (as many total proton-proton collisions) as what the particle physicists need to look for things like the Higgs.  So we’re having a short run with proton-proton collisions at a lower energy because it will significantly help the heavy ion physics program.  (We’ll also get some core physics measurements out of the 2.76 TeV proton-proton data, but like the paper I discussed here, these will refine our understanding but not dramatically change our understanding of proton-proton collisions.)  I hope you’re as excited as I am!


Witness to Beauty

Tuesday, March 22nd, 2011

–by Lindsay Davies, Communications Assistant

G’day Mates!

Less than 24 hours ago, I had the opportunity of a lifetime and plunged into the depths of the Great Barrier Reef off the coast of Cairns, Australia. The largest reef system, it encompasses an area of over 344,400 square kilometers – including over 2,900 individual reefs, 900 islands, and over 15,000 species of fish and wildlife.

If you need a jolt of reality to put things into perspective – scuba diving at the Great Barrier Reef will do that for you. Entirely surrounded by water, you can’t help but feel so incredibly small in such a vast foreign world. A visitor to the great depths, you witness so much wonder that not even Planet Earth can fully describe how it feels to see it for your own eyes. It’s something you hope everyone can experience for themselves within their lifetimes, but unfortunately there’s so many factors to prevent this – money, time, accessibility… and health.

Just before I left to travel down under, I was able to meet with a few of the individuals who work with the Proton Therapy division within TRIUMF. I knew that we treated patients here at TRIUMF with severe eye melanoma, but that was the extent of my knowledge. They were kind enough to show me the room where the therapy takes place and explain to me the preparation and procedure entailed in treatment, along with some statistics. Our Proton Therapy treatment has an over 90% success rate in curing eye melanoma – in all ages! Unfortunately due to the required power needed to treat patients (70-100 MeV), we need medium-sized accelerator cyclotrons to be built which are expensive (in our case, we primarily use the main cyclotron to get this power). Due to this we can only treat so many patients per year, we only treat the severe cases where the patient has the choice of this, or it is likely they will lose their sight. Despite this, we are still able to give those who pass through our doors a great chance at keeping their eyesight, so they can witness all the great things they know, want to know, and love. Research is also being done to try and reduce the cost of these cyclotrons in order to have the ability to treat more patients all over the world, so we can hope to have more treatments available in the not too far away future!

As a tourist jumping in and observing the beauty the Great Barrier Reef has to offer, you can’t help but feel lucky to witness the beauty, and I like to think that those who receive our treatment will be able to witness similar beauty for themselves.



Tuesday, March 22nd, 2011

As I wrote just last week, the 2011 dataset is going to be huge. And as a promising sign of great things to come: The LHC has already surpassed its previous instantaneous luminosity record!

That means more data, faster. Keep it coming!

I swear I’m not just sitting at home, watching the OP Vistars web page refresh… which it does automatically, btw. You can even have a program announce changes in the beam status out loud! Just saying. 🙂

— Burton