P5 Meetings Discuss Future Physics in the U.S.
In the United States, the particle physics community is creating a plan for the next decade through the Particle Physics Project Prioritization Panel, or P5. The panel is building their plan using input from the summer’s Snowmass on the Mississippi workshop and will evaluate which research goals can be met within the field’s budget. The panel is holding open town hall meetings to encourage physicists to gather together and discuss possible scenarios. In November, the first meeting was held at Fermilab, and in December meetings will be held at SLAC and Brookhaven.
As many of you may know (and some of you may not) the next phase in the long term planning for the future of High Energy Physics (HEP) over the next 10 – 20 years in kicking into gear.
We live in a galaxy permeated with tiny particles called neutrinos. Trillions of them stream through each of us each second. They are everywhere, but much remains a mystery about these particles, which could be key to understanding our universe.
As I’ve discussed a number of times, the United States particle physics community has spent the last nine months trying to understand what the exciting research and discovery opportunities are for the next ten to twenty years, and what sort of facilities might be required to exploit them. But what comes next? How do we decide which of these avenues of research are the most attractive, and, perhaps most importantly, can be achieved given that we work within finite budgets, need the right enabling technologies to be available at the right times, and must be planned in partnership with researchers around the world?
Since 4th July 2012, the physicists at CERN have had a new boson to play with. This new boson was first seen in the searches that were optimised to find the world famous Higgs boson, and the experiments went as far as to call it a “Higgs-like” boson. Since then there has been an intense program to study its spin, width, decay modes and couplings and so far it’s passed every test of Higgs-ness. Whether or not the new boson is the Standard Model Higgs boson is one of the most pressing questions facing us today, as there is still room for anomalous couplings. Whatever the answer is, a lot of physicists will be pleased. If we find that the properties match those of a Standard Model Higgs boson exactly then we will hail it as a triumph of science and a fitting end to the quest for the Standard Model which has taken the work of thousands of physicists over many decades. If we find some anomaly in the couplings this would be a hint to new physics hiding “just around the corner” and tease is with what we may see at higher energies when the LHC turns on again in 2015.
For those who have read my blog for a long time, you may remember that I wrote a post saying how I was skeptical that we would find the Standard Model Higgs boson. In fact I even bet a friend $20 that we wouldn’t find the Standard Model Higgs boson by 2020, and until today I’ve been holding on to my money. This week I found that ATLAS announced the results of their search for the Higgs boson decaying to two tau leptons, and the results agree with predictions. When we take this result alongside the decays to bosons, and the spin measurements it’s seems obvious that this is the Higgs boson that we were looking for. It’s not fermiophobic, and now we have direct evidence of this. We have see the ratio of the direct ferimonic couplings to direct bosonic couplings, and they agree very well. We’d had indirect evidence of fermionic couplings from the gluon fusion production, but it’s always reassuring to see the direct decays as well. (As a side note I’d like to point out that the study of the Higgs boson decaying to two tau leptons has been the result of a huge amount of very hard work. This is one of the most difficult channels to study, requiring a huge amount of knowledge and a wide variety of final states.)
Now the reason for my skepticism was not because I thought the Standard Model was wrong. In fact the Standard Model is annoyingly accurate in its predictions, making unexpected discoveries very difficult. What I objected to was the hyperbole that people were throwing around despite the sheer lack of evidence. If we’re going to be scientists we need to rely on the data to tell us what is real about the universe and not what some particular model says. If we consider an argument of naturalness (by which I mean how few new free terms we need to add to the existing edifice of data) then the Higgs boson is the best candidate for a new discovery. However that’s only an argument about plausibility and does not count as evidence in favour of the Higgs boson. Some people would say things like “We need a Higgs boson because we need a Brout-Englert-Higgs mechanism to break the electroweak symmetry.” It’s true that this symmetry needs to be broken, but if there’s no Higgs boson then this is not a problem with nature, it’s a problem with our models!
The fact that we’ve seen the Higgs boson actually makes me sad to a certain extent. The most natural and likely prediction has been fulfilled, and this has been a wonderful accomplishment, but it is possible that this will be the LHC’s only new discovery. As we move into LHC Run II will we see something new? Nobody knows, of course, but I would not be surprised if we just see more of the Standard Model. At least this time we’ll probably be more cautious about what we say in the absence of evidence. If someone says “Of course we’ll see strong evidence of supersymmetry in the LHC Run II dataset.” then I’ll bet them $20 we won’t, and this time I’ll probably collect some winnings!
This summer, The New York Times’ Opinionator blog posted a photo of an ordinary, fluorescent-lit hallway, indistinct apart from one feature: a placard proclaiming “Dungeon” in tall capital letters. As part of the blog’s “summer game” series, readers were asked to guess the context of the photo. Many correctly guessed “conference room,” but none deduced the precise location: Fermi National Accelerator Laboratory, a Department of Energy-funded high-energy physics lab in the suburbs of Chicago.
As it turns out, Fermilab plays host to a trove of whimsical, bizarrely named conference rooms.
While the Dungeon is found in the lab’s Cross Gallery, a building dedicated to accelerator operations, most of the conference rooms are housed in the lab’s main office building, Wilson Hall. John Kent, the building manager for Wilson Hall, said that rooms are often named by those who would most often use them. The building, modeled after a Gothic cathedral in Beauvais, France, has one of the world’s largest atriums, and, at 16 stories, it towers over the rest of the lab grounds. Much of the work conducted there translates into high-tech particle accelerator experiments and contributions to scientific discoveries such as the Higgs field.
Let’s explore, from the ground up.
1. Names of meeting rooms start out simple and ordinary on the first floor: One North, One East, One West and The Small Dining Room.
2. The second floor, though, is where things start to get weird. For starters, both the Black Hole and the Snake Pit flank the north end of the building. Then, the Comitium is just a short jog away, its name stemming from the Latin word for “assembly.” Fermilab’s first director and Wilson Hall’s namesake, Robert Wilson, chose that one personally as a hat tip to the so-named outdoor public meeting spaces of ancient Rome — Wilson had spent some time studying art in Italy prior to his directorship days.
Wilson also named Curia II, another second-floor conference room (preceded by the Curia in the Fermilab Village), this time after a Latin word thought to derive from the word “coviria,” meaning a “gathering of men.” No word on how Fermilab’s female employees feel about this.
As one climbs higher in the Brutalist concrete tower that is Wilson Hall (there’s a reason it’s also called the high-rise), the conference rooms get fewer and farther between.
3. The third floor only has two of them, and while they sometimes go by “Theory Conference Rooms 3-Northeast and 3-Northwest,” the names Conjectiorium and Theory lend more individuality.
4. The fourth floor, though equally scant in its conference room offerings, has a bit more flair. The Req Room’s name conjures up visions of Hogwarts’ Room of Requirement, while the Abacus was christened in an employee naming-contest.
5. The ConFESSional, on the fifth floor, plays with the acronym for Fermilab’s Facilities Engineering Services Section and, together with the Baptismal and Tabernacle, creates some kind of holy trinity of religion-themed conference room names.
6 and 7. Up a floor, the Dark Side channels George Lucas. Then, on seven, there’s the Racetrack (perhaps paying homage to the particles that some accelerators hurtle around a circular tunnel at high speeds). Other sports-themed conference rooms include the Bullpen, also on the seventh floor, the 19th Hole, on 14, and elsewhere on the Fermilab grounds, the Outfield, in MW-9 near the Meson Assembly Building.
8. Wilson Hall’s eighth floor’s claim to fame is the Hornet’s Nest, marked by an actual hornet’s nest on display. A plaque by the nest jokingly says “a piece of the DZero Muon Chamber.” The detector from the DZero experiment was one of two that were positioned along the now shut-down Tevatron accelerator ring; muon chambers made up the outermost layer of DZero’s detector. Colorful signs posted on either side of the conference room state the words or phrases for “hornet’s nest” in many languages: “zes muv,” “avispero,” “nido del calabrone,” “Hornissennest.”
In its day, the buildings housing the DZero experiment had a few quirky room titles of their own, among them: Hurricane Deck, Doghouse, Salles Des Heros (“room of heroes” in French) and the Far Side. The latter might be a nod to the popular cartoonist Gary Larson, who often draws tongue-in-cheek portrayals of scientists in his comics. Too bad for DZero, though; Larson already has a species of lice named after him — Strigiphilus garylarsoni — and is unlikely to be wooed by a conference room namesake.
9. It seems most likely that Wilson Hall ninth floor’s Libra is yet another reference to a Latin term rather than a zeal for the astrological. But you never know.
11. Users may watch the sun rise from the Sunrise conference room, located on the northeast corner of the 11th floor, or enjoy a view of the setting sun from the southwest corner of 11, in the Sunset conference room.
12. The 12th floor houses the Nu’s Room, which has nothing to do with the HBO drama series and everything to do with the Greek letter v. In particle physics, v, or nu, represents subatomic particles called neutrinos.
15. The highest conference room in Wilson Hall is the Aquarium. One can only imagine how often mix-ups occur with the Quarium, a room located on floor 8.
About 2,500 researchers from 34 countries collaborate on Fermilab experiments, some of them full-time employees and more of them visiting experimenters from other institutions. If one thing is clear from this list, it’s that researchers from all different backgrounds can be brought together by puns, inside jokes, dead languages, offbeat pop culture references and passed-down traditions.
Si vous n’avez pas eu la chance de visiter le CERN à Genève, vous pouvez maintenant le faire à Londres. En effet, le Musée de la science de Londres vient tout juste d’ouvrir une nouvelle exposition intitulée : Collider. J’ai pu la visiter et peux confirmer que cette exposition transmet réellement l’impression d’être au CERN.
L’exposition, ouverte jusqu’en mai 2014, explore les personnes, la science et l’ingénierie derrière la plus grande expérience scientifique jamais construite, le Grand collisionneur de hadrons (LHC) du CERN.
L’exposition commence dans un petit amphithéâtre où les visiteurs ont le sentiment d’assister à la réunion tenue dans celui du CERN le 4 juillet 2012. C’était le jour où l’on a annoncé la découverte d’une nouvelle particule, qui s’avéra bien être un boson de Higgs. Quelques physicien-ne-s y partagent leurs impressions sur la physique des particules et leur participation aux travaux ayant mené à cette découverte.
Comme la conservatrice Alison Boyle nous a expliqué à mes collègues et à moi, leur idée était de décrire en essence les diverses personnes qu’ils et elle avaient rencontrées au CERN au cours des deux années requises pour préparer cette exposition. Bien que quelques personnages nous aient semblé légèrement étranges, d’autres étaient drôlement familiers.
Les professeurs Peter Higgs et Stephen Hawking durant leur visite de l’exposition Collider (© Science Museum)
L’exposition est stupéfiante dans son utilisation intelligente de différents effets visuels. Les visiteurs traversent des pièces aux murs couverts d’images grandeur nature représentants des endroits clés du CERN, donnant l’impression d’y être. Des notes griffonnées sur des tableaux ou des bouts de papiers collés aux murs, comme on en voit tant partout au CERN, renforcent la similitude tout en fournissant les explications nécessaires. De vrais objets rehaussent les images pour créer une ambiance bien spéciale. Une super animation vidéo donne aussi une idée de ce que les particules rencontrent lors de leur passage à travers les détecteurs.
Mais pour les gens du CERN, l’élément le plus surprenant est la reproduction d’un couloir dans toute sa splendeur d’architecture des années 1950. Les murs vieillots sont couverts d’affiches annonçant toute une série de conférences passées ou futures ainsi que des activités locales, aussi bien celles du choeur du CERN que du groupe LGBT. J’ai eu l’impression d’être au travail tout en me trouvant à des milliers de kilomètres de distance.
Si vous ne pouvez pas venir visiter l’original, voici donc un excellent succédané qui vous plongera dans l’ambiance du CERN. L’exposition partira éventuellement en tournée à travers le monde, donnant ainsi la chance à plus de monde de voir un peu comment ça se passe au plus grand laboratoire de physique du monde.
Vous pouvez suivre le blog de l’exposition ici.
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If you have not had a chance to visit CERN in Geneva, you can now do it in London. The London Science Museum just opened a new exhibition called: Collider. I had the opportunity to visit it and can confirm that this exhibition conveys the impression of being at CERN.
The exhibition, open until May 2014, explores the people, science and engineering behind the largest scientific experiment ever constructed, the Large Hadron Collider at CERN.
The exhibition starts in a small amphitheatre where visitors get the feeling of sitting in CERN main auditorium on 4 July 2012. That was the day the discovery of a new particle, which was later confirmed to be a Higgs boson, was announced. There, a few physicists share their thoughts about particle physics and their participation in that search.
As the curator Alison Boyle explained to my colleagues and I, they tried to portray the essence of various people they had met at CERN over the two years it took them to prepare this exhibition. Although some characters seemed slightly odd, others were strangely familiar.
The exhibit is stunning in its clever use of visual effects. Visitors wander at their own leisure through rooms where the walls are covered with life-size pictures of various places at CERN, giving them a sense of being there. Notes scribbled on boards or pieces of papers taped to the wall as one often finds all over the place at CERN add to the likeliness and provide the necessary explanations. Real objects enhance the pictures to create a very special ambiance. A great video animation also gives a feel for what particles go through as they zip through the detectors.
But for CERN people, the most surprising piece is the reproduction of one corridor in its 1950s architecture glory. The walls are pasted with posters announcing a plethora of past and future conferences as well as local events, from the CERN choir down to the LGBT group. It felt like being at work thousands of kilometres away from work.
So if you cannot come see the real thing, this is an excellent substitute to get immersed in CERN ambiance. The exhibition is due to go on tour across the world, giving even more people a chance to experience what it feels like at the world’s largest physics laboratory.
You can follow the exhibition blog here.
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As many of you may know (and some of you may not) the next phase in the long term planning for the future of High Energy Physics (HEP) over the next 10 – 20 years in kicking into gear.
The centre piece of this phase is a panel of scientists who have been appointed to develop a strategy based on the various important pieces of physics, planned experiments, and various budget scenarios HEP faces. This panel is (terribly) named the Particle Physics Project Prioritization Panel, or more commonly referred to as P5. (www.interactions.org/p5)
This panel is meeting immediately following the summer study known as Snowmass to seize on the opportunities for interesting physics that were brought forward during this 8 month long study.
I was personally involved in one aspect of the Snowmass study by trying to get young (untenured) scientists to participate in the Snowmass study and to help ensure that their positions and opinions were heard. The group that I helped lead was known as Snowmass Young (http://snowmassyoung.hep.net) and through an online survey as well as attending countless meetings we attempted to capture these opinions in a paper which you can now find on the arxiv! (Snowmass 2013 Young Physicists Science and Career Survey Report)
However, our work hasn’t stopped there. With the P5 holding open town halls last month as well as December Snowmass Young has been trying to ensure that all voices are heard during this important process. The great news is we have been met with open and encouraging arms. The chair of the P5 process, Prof Steve Ritz, has met with Snowmass Young to hear from us and encourage all young scientists to come to the P5 town hall meetings and have their voices heard. Prof Ritz has written a letter to the young community which can be found in full here and I quote below:
The purpose of this note is to reaffirm that engagement by everyone in our community, including Snowmass Young Physicists, is needed.
Each of the upcoming meetings (our first face-to-face meeting on 2-4 November at Fermilab, then 2-4 December at SLAC, and 15-18 December at Brookhaven) has a Town Hall, and all sessions except the executive sessions are completely open. I encourage you to attend and participate. The Town Halls are deliberately unstructured: most of the time will be devoted to open-mike statements and discussions. If there is something you want to say, just come up to one of the microphone stations in the aisles.
Don’t be subtle! Let us hear from you about your concerns, advice, and input.
With these words in mind Snowmass Young is working to make sure that as many opinions are heard at the upcoming P5 meetings. The Fermilab meeting has already passed with only limited attendance from young people, so we want to work hard to change that for the upcoming meetings.
All scientists (especially young scientists) have received encouragement to attend the upcoming P5 meeting at SLAC from Kelen Tuttle (Editor in Chief at Symmetry Magazine) in the below letter where more details can be found
SLAC will host the next Particle Physics Project Prioritization Panel (P5) meeting on Dec. 2-4, and you’re invited!The meeting, which will focus on the Cosmic Frontier, is open to all and will take place in SLAC’s Kavli Auditorium with overflow in Redwood C&D. In addition, the meeting will be live-streamed online (details on how to access the feed will be posted to the meeting website soon: https://indico.bnl.gov/conferenceDisplay.py?confId=688). Although there won’t be a way for online viewers to comment or ask questions in real time, the P5 committee welcomes feedback via its online form: http://www.usparticlephysics.org/p5/formP5 held the first town hall at Fermilab in early November, and will follow the SLAC meeting with another at Brookhaven National Laboratory Dec. 15-18.In addition to the three town hall meetings, P5 is receiving input from the US Department of Energy, the National Science Foundation, and the full community via the Snowmass process. The end goal is a new strategic plan for US high-energy physics investments over the next 10 to 20 years. The plan will offer a coherent path forward, building a strong position from which the US high-energy physics community, working with the international community, can answer grand scientific questions and improve our understanding of nature.More information can be found at: http://www.usparticlephysics.org/p5
For the upcoming Brookhaven meeting Elizabeth Worcester (a Snowmass Young convener and brilliant research scientist) is organizing a dedicated session during the meeting as a way to help entice more people to attend. You can find her letter below with more details
Dear colleagues,As you may know, a P5 Workshop on the Future of High Energy Physics is being held at Brookhaven National Lab, December 15-18, 2013 (http://www.bnl.gov/p5workshop2013/). The P5 committee has strongly encouraged early-career physicists to attend the workshops, participate in the Town Halls, and provide input to the P5 process. To further facilitate input from early-career physicists, a Young Physicists Forum is being held at the BNL meeting, during the lunch hour on Monday, December 16. The chair of P5, Steve Ritz, has agreed to speak briefly at the forum and answer questions from the young community. We encourage pre-tenure scientists who wish to learn about the P5 process and/or share their perspectives to attend the workshop and this forum.Please help us spread the word by encouraging any young scientists who may not be on this list to attend. For planning purposes, please contact Elizabeth Worcester (firstname.lastname@example.org) if you plan to attend the Young Physicists Forum.Best,Elizabeth, for the Snowmass Young conveners
Too many of the attempts to sell science are like the proverbial minister preaching to the choir: they convince nobody but the already converted. This is unfortunate because we, as scientists, have a duty and a responsibility to sell science to a wider audience. There are four motivations for this:
- There are important technical questions that can only be answered by the scientific method. These include, for example, what is causing global warming? Or why are the returning salmon runs in British Columbia so erratic? We must make the case that science and only science can address these types of questions and that the answers science provides should be listened to.
- To provide answers to questions like those above, science must have ongoing support since the answers can only come from a scientific infrastructure that is maintained for the long haul. In addition to answering practical questions, science also has the important cultural role of satisfying human curiosity. To satisfy either the practical or cultural goals, science needs support from the public purse. This means science must be sold to politicians and the general public who elect them and support science through their taxes.
- We need to excite the next generation’s best and brightest to consider science as a career. This is the only way that we can ensure science’s future.
- Selling science is rewarding and can even be fun. You should have seen the fun both TRIUMF staff and visitors had at the last TRIUMF Open House. There is also something contagious about explaining a topic you are passionate about.
The allusions to religion in the opening sentence are appropriate as many attempts to sell science come across as a claim that science is the one true religion and anyone who disagrees is a fool. While that may, indeed, be true, hollering it from the hill tops is a strategy doomed to failure. A frontal attack on a major component of a person’s world view will only arouse hostility. Hence, to sell science, we have to start with a common ground with the audience. To achieve maximum impact, you have to know your audience and tailor what you say to its interests.
However, there are three things that should be part of any attempt to sell science:
- A definition of what science is. This may seem self-evident but I have seen seminars on selling science that carefully avoided any attempt to define what science actually is. I have this real nice pig in the poke to sell you. Even worse are attempts to define science that are wrong and/or annoy people. A major impediment to selling science is that there is no commonly accepted definition of what science is. However, allow me to offer a fairly safe definition: using observation as a basis for modeling how the universe works. This definition is simple, understandable and reasonably accurate. Alternatively, one can talk about the ability to make testable predictions as the hallmark of the scientific method. Use the word theory sparingly as that word has multiple meanings and invariably leads to confusion. Using words like objective reality, truth, or fact is a real turn off to many audiences. Besides, every Christian will tell you that Jesus is the truth and the more fundamentalist Christians that the bible is fact. You cannot win with those words, avoid them.
- Examples of scientific successes. This is the greatest strength in selling science. We have a plethora of examples to choose from, but it is probably not a good idea to start with the nuclear bomb. Again, it is important to understand the audience. To a person talking non-stop on his cell phone, the cell phone would be a good example (if you can get his attention) but to other people the cell phone is an anathema. The same is true of almost any example you can choose. After all, curing disease (and motherhood) leads to world overpopulation. On TV or radio, the role of science in enabling TV and radio is a good bet. On YouTube, the internet would be a good example. Despite the comment above, curing disease usually gets brownie points for science. But claiming the Higgs boson cures cancer is a bit of a stretch.
- Your personal experience of the thrill of science; whether it is for the good of humanity or just learning more about how the universe works. It is here that the emotional aspect of science can come to the fore. To some of us, the hunting of the Higgs boson is more thrilling than hunting grizzly bears and probably more environmentally friendly. Using personal experience may seem as going against our training as scientist; but here we can learn from the professionals, those who sell religion or political parties: Do not talk about theology but your personal experience. Do not talk about the platform but your own experience. In the end, this may be a telling argument and it is important to counter the stereotype of the mad scientist in his (almost always male) laboratory plotting world domination or ignoring the obvious flaws in his theory and its disastrous side effects. Drs. Faustus and Frankenstein are never far from people’s conception of the scientist.
You would think that selling science would be easy. We have a well-defined technique, four hundred years of successes to prove its usefulness and the thrill of the hunt. But we are up against two formidable foes: competing world views and vested interests. If someone believes they will be raptured to Heaven in the near future, learning about the world below is not a high priority. Similarly if they subscribe to the old hymn, I Don’t Want to Get Adjusted to This World Below, finding a crack in which to start a conversation is difficult.
In the same vein, if you have spent your life building a tobacco empire the last thing you want is some scientist claiming tobacco causes cancer. Or if you have made selling tar-sands oil a key political plank, you do not want scientists claiming it is destroying the earth. In these cases, science, itself, tends to become the target of the counterattack. With the world’s best public-relations machines powered by religion, politics and vested interests in opposition it is not at all clear that the efforts to sell science will be successful. But we must try. The motivations are so compelling, we must try.
Acknowledgement: I would like to thank T. Meyer and members of the TRIUMF Communications Group for comments on various drafts of this post.
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 Or not, as the case may be.
 My Quantum Diary blogs support this definition of science.
 Unless you are in Los Alamos.
 A well-known mega church pastor.
 Obama campaign worker.
This article appeared in symmetry on Nov. 12, 2013.
Scientists interested in protons and the sea of particles that compose them are in good spirits this week. Researchers from 15 different institutions that participate in the SeaQuest experiment are watching beam flow into their experiment and data flow out.
The SeaQuest experiment, based at Fermilab and managed by a group of scientists from Argonne laboratory, studies the structure of protons and the behavior of the particles of which they’re made.
Protons contain a constantly simmering sea of particles bound together by the aptly named strong force, which is the strongest of the four fundamental interactions of nature—above the weak force, electromagnetism and gravity.
In the experiment, a particle accelerator sends a beam of protons at very high speeds into a target made of either liquid hydrogen or deuterium or solid carbon, iron or tungsten. These bursts of beam come once a minute and each last about 5 seconds.
This causes protons to essentially break apart and release the quarks and antiquarks within. (Antiquarks are the antiparticle of quarks, meaning they have the same mass but opposite charge.)
SeaQuest physicists will then study in great detail the particles that are released during these interactions. Their aim is to resolve questions about the particles that make up the visible mass in our universe.
Initially, experimenters hope to shed light on the internal structure of protons, specifically, the ratio of anti-up quarks to anti-down quarks—two types of antiquarks with different properties.
Results from SeaQuest’s predecessor, NuSea, and DESY’s Hermes experiment, both reported in 1998, found a surprise in measuring the ratio of anti-down quarks to anti-up quarks in the proton; it trended toward a value of less than one. This shook up current assumptions about symmetry between these particles and might hint that we have an incomplete understanding of the strong force.
SeaQuest is re-examining this notion, using beam with about one-eighth of the energy and 50 times the luminosity of that of NuSea.
“We think in several months we will have enough data to confirm what NuSea saw,” says Argonne physicist Paul Reimer, spokesperson for SeaQuest. “Then we of course want to do better, which will take a year or more after that.”
The experiment is also intended to study how exactly the strong force binds these subnuclear particles together and how those effects are modified when the proton is inside an atom’s nucleus rather than isolated and separated from it. Quarks’ angular momentum, also called their “spin,” is known to be distributed differently depending on if the proton is “free” or if it is bound inside a nucleus at the time.
Yet another goal of the experiment is to measure how much energy quarks lose as they pass through cold nuclear matter. Both of these pursuits will be explored simultaneously.
The last time SeaQuest saw beam, during a commissioning run, it lasted about six weeks, from March 8 to the end of April 2012. The data from that run, Reimer says, was useful for debugging the detector and hammering out the algorithms they need to take data this time around.
Over the past year and a half, while beam was shut down for scheduled upgrades, SeaQuest researchers and technicians used that downtime to make technical improvements to the experiment’s spectrometer (pictured above) to enable higher beam quality and smoother delivery of protons, which should result in greater accuracy.
University of Michigan postdoc Josh Rubin says the detector and experiment are ready to take on the mysteries of the proton.
“We are all excited at the chance to study the sea of quarks,” he says.
A version of this article appeared in symmetry on Nov. 5, 2013.
The same particle-physics technology used to understand the universe is also used to improve health and medicine. Accelerators and detectors play an important role in diagnosing disease, shrinking tumors and sterilizing medical equipment. Large-scale computing makes it possible to determine which potential new drugs are most likely to work before starting large-scale human trials. And particle-physics-trained scientists serve as medical physicists, making sure it all works as planned.
Sterilizing instruments and supplies
Particle physics technology can be used to disinfect syringes, bandages, scalpels, stethoscopes and other tools without damaging them. Medical equipment is sent through a series of small particle accelerators and bombarded with beams of electrons or X-rays. In a matter of seconds, the beams eradicate any surface microbes.
Distributed and grid computing
The World Wide Web is not the only computing advancement to come out of particle physics. In order to cope with the huge amount of data produced by experiments, particle physicists developed a network of grids allowing multiple users to share computing power and storage capacity. The grid concept has a number of uses in the medical field, including screening drug candidates to determine which ones are most likely to fight disease.
Practice makes perfect, and when it comes to our health, the closer to perfect, the better. So some doctors and medical physicists are designing treatment plans using modeling tools developed for particle physics to predetermine the electromagnetic and nuclear interactions of particles with tissue. In radiation therapy, this software can help doctors understand what will happen when a beam of particles passes through a patient’s body.
In the heart of particle physics detectors around the world, hundreds of detectors made with silicon semiconductors splay out around particle collision points, tracking charged particles to create pictures of their paths. Physicians make use of this semiconductor technology in many medical devices, including semiconductor lasers. These discrete beams of high-intensity light are perfect for delicate operations like eye surgery.
Many particle physicists can be found inside hospitals and clinics. Particle physicists who cross over into the medical field often come with extensive training in the operation and maintenance of accelerators. With their thorough understanding of particle beams, these scientists are highly valued as specialists who manage the medical imaging systems that detect tumors and who operate the accelerator beams that kill cancer cells.
PET scanners are common tools that let medical professionals examine organs and tissues inside the body. The PET scanner’s genealogy traces back to detector technologies developed in the 1980s to identify individual photons in particle physics experiments. It may sound strange, but PET scanners use antimatter produced inside the body. When a special tracer is injected into a patient, a type of radioactive decay occurs, emitting positrons—the antimatter counterparts to electrons. These positrons annihilate with nearby electrons, releasing bursts of photons. The photons are detected and compiled into three-dimensional images.
Magnetic resonance imaging, the basic principles of which emerged from early research in physics, is more discerning than traditional screening, which sometimes can’t make out tumors hidden within dense tissue. When a patient is subjected to the powerful magnetic field inside an MRI machine, atoms inside his body line up in the direction of the field. A radio frequency current is temporarily switched on, causing the protons inside those atoms to flip around until the radio frequency is removed. At that point, the protons pivot back into place—each at a different rate. The varying rates are measured, allowing scientists to determine what’s happening inside the living tissue.
One of the most effective techniques to fight cancer uses the same technology particle physicists employ to accelerate particle beams to nearly the speed of light. There are more than 17,000 particle accelerators worldwide used for the diagnosis and treatment of disease. Doctors exchange a scalpel for a beam of charged particles, which they aim at cancerous tissue, killing malignant cells by destroying DNA strands in the nuclei while sparing the surrounding healthy tissue.
While my family and I are spending a year at CERN, our Subaru Outback is sitting in the garage in Lincoln, under a plastic cover and hooked up to a trickle charger. We think that we hooked it all up right before going, but it’s hard to know for sure. Will the car start again when we get home? We don’t know.
CMS is in a similar situation. The detector was operating just fine when the LHC run ended at the start of 2013, but now we aren’t using it like we did for the previous three years. It’s basically under a tarp in the garage. When proton collisions resume in 2015, the detector will have to be in perfect working order again. So will this car start after not being driven for two years?
Fortunately, we can actually take this car out for a drive. This past week, CMS performed an exercise known as the Global Run in November, or GRIN. (I know, the acronym. You are wondering, if it didn’t go well, would we call it FROWN instead? That too has an N for November.) The main goal of GRIN was to make sure that all of the components of CMS could still operate in concert. In fact, many pieces of CMS have been run during the past nine months, but independently of one another. Actually making everything run together is a huge integration task; it doesn’t just happen automatically. All of the readouts have to be properly synchronized so that the data from the entire detector makes sense. In addition, GRIN was a chance to test out some operational changes that the experiment wants to make for the 2015 run. It may sound like it is a while away, but anything new should really be tested out as soon as possible.
On Friday afternoon, I ran into some of the leaders of the detector run coordination team, and they told me that GRIN had gone very well. At the start, not every CMS subsystem was ready to join in, but by the end of the week, the entire detector was running together, for the first time since the end of collisions. Various problems were overcome along the way — including several detector experts getting trapped in a stuck elevator. But they believe that CMS is in a good position to be ready to go in 2015.
As a member of CMS, that was really encouraging news. Now, if only the run coordinators could tell me where I left the Subaru keys!
The Open University asked me to write an article on my time at CERN over the summer. I replicate the article below which was published by the OU on 5 November 2013 here. The article pulls together my experiences on the CERN Summer Programme and provides links to particular blog entries on this site should you wish to learn more. Enjoy!
I got lucky – very lucky. For I spent this summer at CERN in Switzerland at the world’s greatest laboratory and the birthplace of the Nobel-winning Higgs boson. I am studying physical sciences with the OU and in this article I recount an incredible, challenging and unforgettable summer. I also include links to my blog which you can click to learn more about life at CERN.
What is CERN?
CERN, or the European Organization for Nuclear Research, is an international organisation which operates the world’s largest particle physics laboratory. At CERN scientists use complex scientific instruments to probe the fundamental structure of the universe and basic constituents of matter – fundamental particles.
CERN is the home of the world’s largest machine, the Large Hadron Collider (LHC): a 27km circular particle accelerator that collides particles which are travelling at close to the speed of light. The LHC was used to observe the Higgs boson, a particle which is the by-product of a mechanism by which other fundamental particles acquire mass. This observation led to Peter Higgs and Francois Englert being announced as winners of a Nobel Prize for Physics in October 2013.
The Student Summer Programme
Each year CERN invites around 300 physics, engineering and computer science students from across the globe to participate in its Summer Student Programme. The programme affords students the opportunity to attend a six week lecture series on particle physics and related topics, and also to carry out a research project.
Learn more about the CERN Summer Student Programme here.
CERN is plonked in the midst of beautiful agricultural estates which nestle between the Alps and Jura mountain ranges, with several sites on either side of the Swiss-French border. Smaller experiments are based on the main Meyrin site on the outskirts of Geneva, while larger accelerators, such as the LHC, extend into France.
On arrival one is rather taken aback by how plain, industrial and, dare I say, ugly CERN is. Buildings are haphazardly distributed and typical of 1960 university campus architecture. But there is more to CERN than first meets the eye.
More first impressions here.
What are the people like?
There are approximately 10,000 people on the CERN site each day who hail from all corners of the Earth. One need only walk into the main restaurant at lunchtime to sense the excitement in the air at CERN. People know they’re involved with something special and they want to be there. The diverse, multicultural and enthusiastic workforce creates a fantastic atmosphere.
The lecture series was intense, technical and extremely interesting. Topics ranged from theoretical and mathematical subjects, such as the Standard Model and Supersymmetry (theoretical models which explain how fundamental particles interact), to more applied and technical topics, such as the operation of particle accelerators and detectors. Lectures were delivered by leaders in the field and daily Q&A sessions provided an excellent opportunity to interrogate them.
More on the lecture series here.
I worked in the Beam Instrumentation Group to develop a new type of beam position monitor (BPM) for the LHC. This is a gizmo which measures the position of the beams of particles which circulate around the LHC so that they can be kept on target. The project was very hands-on and involved playing with lasers and crystals. This new type of BPM might someday be installed in the LHC so it was exciting to be involved with its development.
The social life
Bringing together 300 students inevitably leads to an active social scene. There was lots going on including parties on site, trekking in the mountains, trips to nearby Swiss towns, dance classes, and music festivals. Geneva also provided enough entertainment, cheese and wine to keep most amused, satiated and merry. My favourite activity was having a swim in Lake Geneva.
What did I learn?
I learned a lot at CERN. One of the most striking features of modern physics is that we are still largely in the dark – literally. The matter which everything we can see, including ourselves, is composed of makes up a mere 4% of the universe. The rest is dark matter and dark energy. Supersymmetry holds some promise for a deeper understanding of dark matter but as far as dark energy – which accounts for 73% of the universe – is concerned, we haven’t got the foggiest. It is this kind of mystery which I think makes science so alluring.
I also learned that there are exciting times ahead for physics. CERN is mostly closed for business at the moment as its accelerators are being upgraded but when the LHC is switched back on in 2015, it is going to reach incredible collision energies approaching 7 TeV. Higher energies means different kinds of stuff might fly out of the particle collisions. So the observation of the Higgs boson may be just the tip of the iceberg of a whole new generation of fundamental particles and physics.
Will I go back?
I had a fantastic time at CERN and would love to return one day… if they’ll have me.