## Archive for January, 2013

### Higgs to light video comes to light

Thursday, January 31st, 2013

Just a quick note here on something that isn’t really mine: CMS has now released some video footage from the internal meetings where the results of the search for a Higgs particle decaying to a pair of photons (light) were first presented to the collaboration. I think it’s pretty interesting to watch this little bit of science history.

Here is the context: the Higgs searches were done “blind”, in that every little bit of the analysis was done without examining the actual detector data sample where the Higgs might be observed. Using simulations and data samples that are similar to, but not actually, the data in question are used to design the Higgs search, to understand what the experimental uncertainties are, and to give an expectation of what would be seen in the data if there were a Higgs (or not). Everyone avoids looking at the key data samples to avoid biasing the search based on what is seen. (The fear is that if you see a small signal, you might start to make changes in the analysis to enhance the signal…which could turn out to be a statistical fluctuation in the end.)

Then, in the late stages of the data analysis, we finally take a look at the “signal” sample. Of course, someone has to be the first person to do this, which means that for a brief moment, that’s the only person in the world who knows a new scientific fact. And then there is a lot of suspense for everyone else! In the video, someone who was among the first to see the result, just hours beforehand, is presenting it to the rest of the collaboration. You can certainly see how excited the presenters are about that moment.

I suppose there isn’t any suspense now, since we know what the answer is, but try to put yourself in the mindset of the audience in the room…and enjoy!

### Tweeting the Higgs

Wednesday, January 23rd, 2013

Back in July two seminars took place that discussed searches for the Higgs boson at the Tevatron and the LHC. After nearly 50 years of waiting an announcement of a $$5\sigma$$ signal, enough to claim discovery, was made and all of a sudden the twitter world went crazy. New Scientist presented an analysis of the tweets by Domenico et al. relating to the Higgs in their Short Sharp Scient article Twitter reveals how Higgs gossip reached fever pitch. I don’t want to repeat what is written in the article, so please take a few minutes to read it and watch the video featured in the article.

The distribution of tweets around the July 2nd and July 4th announcements (note the log scale)

Instead of focusing on the impressive number of tweets and how many people were interested in the news I think it’s more useful for me as a blogger to focus on how this gossip was shared with the world. The Higgs discovery was certainly not the only exciting physics news to come out of 2012, and the main reason for this is the jargon that was used. People were already familiar with acronyms such as CERN and LHC. The name “Higgs” was easy to remember (for some reason many struggled with “boson”, calling it “bosun”, or worse) and, much to physicists’ chagrin, “God particle” made quite a few appearances too. It seems that the public awareness was primed and ready to receive the message. There were many fellow bloggers who chose to write live blogs and live tweet the event (I like to think that I started bit of a trend there, with the OPERA faster than light neutrinos result, but that’s probably just wishful thinking!) Following the experiences of December 2011, when the webcast failed to broadcast properly for many users had twitter on standby, with tweets already composed, hungry for numbers. The hashtags were decided in advance and after a little jostling for the top spot it was clear which ones were going to be the most popular. Despite all the preparation we still saw huge numbers of #comicsans tweets. Ah well, we can’t win them all!

The point is that while the world learned about the Higgs results I think it’s just as important that we (the physicists) learn about the world and how to communicate effectively. This time we got it right, and I’m glad to see that it got out of our control as well. Our tweets went out, some questions were asked and points clarified and the news spread. I’m not particularly fond of the phrase “God particle” , but I’m very happy that it made a huge impact, carrying the message further and reaching more people than the less sensational phrase “Higgs boson”. Everyone knows who God is, but who is Higgs? I think that this was a triumph in public communication, something we should be building on. Social media technologies are changing more quickly each year, so we need to keep up.

A map of retweets on July 4th, showing the global spread.

I’m glad to see more physicists using Twitter and youtube and other sites to spread the word because that’s where we can build audiences faster. (Incidentally if you want to see why we should be creating new audiences rather than addressing existing ones then see this video by Vihart.) It takes more work and it’s more experimental, but it’s worth the effort. Why did I make an advent calendar? Why tell physics jokes on Twitter? Just to see what works and what doesn’t. I’m not the first person to do these things, and I’m certainly not going to be the last. All I can hope to do is try new ideas out and give other people ideas. I don’t know the people I inspire and those I am inspired by, but that’s also part of the experiment. A lot of my ideas come from people who leave comments or send E-mails or tweets. Occasionally it gets heated and controversial, but if it’s not worth fighting for then it’s not worth saying in the first place. Many comments come from other bloggers too, and we can learn from each other. When I first started to blog someone sent me a few paragraphs of advice and I forgot most of it except one part “Ignore other people’s expectations. Some people will want you to always write about physics, some people will hate that. Write what matters to you.” When I combine that with what Vihart says (essentially “If your content is worth attention then people will pay attention to it.”) then rest is easy. Well, not easy, but less stressful.

But moving back to the main point, the Higgs tweets went global and viral because they were well prepared and the names were simple. Other news included things like the search for the $$B_s$$ meson decaying to two muons and the limits that places on SUSY, but how does one make a hashtag for that? I would not want to put the hashtag #bs on my life’s work. It’s always more exciting to announce a discovery than an exclusion too. The measurement of $$\theta_{13}$$ was just as exciting in my opinion, but that also suffered the same problem. How is the general public supposed to interpret a Greek character and two numbers? I should probably point out that this is all to do with finding the right jargon for the public, and not about the public’s capacity to understand abstract concepts (a capacity which is frequently underestimated.) Understanding how $$\theta_{13}$$ fits in the PMNS mixing matrix is no more difficult than understanding the Higgs mechanism (in fact it’s easier!) It’s just that there’s no nice nomenclature to help spread the news, and that’s something that we need to fix as soon as possible.

As a side note, $$\theta_{13}$$ is important because it tells us about how the neutrinos mix. Neutrino mixing is beyond the Standard Model physics, so we should be getting more excited about it! If $$\theta_{13}$$ is non-zero then that means that we can put another term into the matrix and this fourth term is what gives us matter-antimatter asymmetry in the lepton sector, helping to explain why we still have matter hanging around in the universe, why we have solid things instead of just heat and light. Put like that is sounds more interesting and newsworthy, but that can’t be squeezed into a tweet, let alone a hashtag. It’s a shame that result didn’t get more attention.

It’s great fun and a fine challenge to be part of this whole process. We are co-creators, exploring the new media together. Nobody knows what will work in the near future, but we can look back what has already worked, and see how people passed on the news. Making news no longer stops once I hit “Publish”, it echoes around the world, through your tweets, and reblogs, and we can see its journey. If we’re lucky it gets passed on enough to go viral, and then it’s out of our control. It’s this kind of interactivity that it so rewarding and engaging.

You can read the New Scientist article or the original paper on the arXiV.

### Toshiko Yuasa : la “Marie Curie” japonaise (1909-1980)

Friday, January 18th, 2013

Cette histoire, à cheval entre le LAL (Laboratoire de l’accélérateur linéaire) et l’IPNO (Institut de physique nucléaire d’Orsay), nous retrace le parcours admirable de cette physicienne qui œuvra avec force pour promouvoir les relations entre la France et le Japon.

En 1939, partir travailler à l’étranger était loin d’être évident pour un scientifique Japonais, d’autant plus si ce scientifique était une femme.         C’est pourtant ce que fit Toshiko Yuasa, que l’on connaît aussi comme la première physicienne Japonaise. C’est en France, au collège de France, sous la direction du professeur Frédéric Joliot-Curie, qu’elle commença ses recherches. Avec l’arrivée de la guerre, la physicienne dut quitter à regret la France, mais non sans se faire confier du matériel par ses collègues français, ce qui lui permit de poursuivre ses travaux. Une fois la guerre passée, c’est avec une certaine hâte qu’elle retourna en France, au CNRS, à l’IPNO, pour y mener 30 ans de carrière. Durant cette carrière et cette vie, elle œuvra remarquablement pour promouvoir les échanges culturels et scientifiques entre la France et le Japon.

Toshiko Yuasa sur le toit du Collège de France - 1941 - © Institut for Gender Studies, Ochanomizu University

Cette figure de l’IPNO a marqué les esprits, par son caractère et en tant que symbole d’une coopération entre la France et le Japon. En 2008, à l’occasion des 150 ans des relations France-Japon, l’IN2P3 a organisé, une cérémonie en sa mémoire, au siège du CNRS. La même année, son nom été attribué au LIA (Laboratoire international associé) Franco-Japonais FJ-PPL. Et enfin, au Japon, à l’université Ochanomizu dont elle était issue, une cérémonie équivalente eut lieu et 2 timbres furent édités en son honneur.

En 2008 la post-doctorante japonaise qui avait organisé les 2 cérémonies, et qui provient de la même université japonaise que Toshiko Yuasa, s’est vue attribuer un poste CNRS au LAL, bouclant ainsi la boucle d’une jolie histoire entre la France et le Japon.

Pour en savoir plus sur cette histoire une biographie de Toshiko Yuasa est disponible ici.

— anecdote fournie par le Laboratoire de l’Accélérateur Linéaire (LAL), unité mixte de recherche du CNRS/IN2P3 et de l’Université Paris Sud, dans le cadre des 40 ans de l’IN2P3.

### Snowmass 2013 Young Physicist Movement

Wednesday, January 16th, 2013

I know it’s been awhile since I posted (I’ve been busy, life in physics is crazy, blah, blah, blah…same excuses for being a bad blogger that everyone gives) but I wanted to bring to the attention of the larger community an interesting process that I am helping to organize and take part in. Namely, the planning process in high energy physics known as Snowmass (on the Mississippi).

This is a conference that is only held every ten years or so as an opportunity to bring together the varying sub-fields of high energy physics (HEP) and begin to lay down a road map of what the future of HEP experiments, theory, and education/outreach will look like. Previously, this conference was held for many weeks in Snowmass, Colorado…however this year it will keep it’s name but be held at the University of Minnesota in Minneapolis.

The part of this that I am most excited about is the opportunity that I’ve been asked to help lead in organizing the “young” people in HEP to have their voice heard and their opinions expressed in this planning process. To this end we have (re)formed a group of undergraduate / graduate / post-doc / un-tenured  scientist working in HEP to take part in the various meetings and plannings leading up to the Snowmass conference in July of this year.

The name of this group is the Snowmass Young Physicist Movement (or Snowmass Young for short). Briefly and broadly speaking we have three main charges:

The first charge for the YPM will be to provide a “deliverable” (some sort of summary) to the Community Summer Study reflecting the attitudes and opinions of young particle physicist on the future of the field and the most pressing concerns held by those of us early in our carrer. Moreover, we desire to engage in the planning process for the next generation experiments being planned now as these will shape the future of the field we hope to inherit.

The next charge of the YPM is to become a long term asset to young physicist. This can be done by providing information and resources to people in high energy physics when making carrer descions. This includes, but is not limited to information about current and planned experiments and collaborations. Additionally we hope to provide resources for those of us who decide to take many skills learned in physics out into the general work force.

Finally YPM aims to provide a chance to for young physicists to network and meet each other as well as become known outside of our particular subfield. To this end, we hope to provide meeting times, spaces, and topics of conversation leading up to and following the Snowmass on the Mississippi. (More on this to come)

Now I know you are asking, “How do I become part of this super exciting group?”

Well, the good news is we have a bunch of ways to join and participate if you are interested in having your voice heard during the Snowmass planning process.

1) Join the mailing list to take part in the planning and orgainizing

If you want to be involved at the level of coordinating and orgainizing and don’t mind receiving a good amount of email about the details of the Snowmass Young planning process subscribe to the mailing list by writing a mail to

LISTSERV (AT) LISTSERV . FNAL . GOV

with an empty subject line, and in the body:

2) If you want to be kept up-to-date with the latest meeting times and news from the physics world follow us on Facebook and Twitter

or
This social media outlet will have events as they are created and live tweeting from meetings and conferences.
3) Check out our website and tell your friends
Finally, Snowmass Young has a website: http://snowmassyoung.hep.net/. Here you can find a calendar of events and this sight will be updated and revised as a final action plan comes into sharper focus.
It is important to remember about all this, the future being discussed during the Snowmass process is the future that we young scientist will inherit! So having our opinions known and expressed is of vital importance to all of us. But even more important, this doesn’t have to be a top down management. This should be a movement!

If you want to lead and have and impact, GO, but please include us. Go to your university, research group, home lab and start the conversation. Find out what matters and communicate that to the larger group.

We have a planning phone meeting scheduled for this Friday. If you would like connection details please message Snowmass Young on Facebook / Twitter / or send an email to snowmass2013young .AT. gmail . com.

We look forward to hearing from everyone!

### Publish or Perish?

Friday, January 11th, 2013

Here I sit with my feet up thinking deep thoughts and some fool tells me I have to publish if I want to get paid. Curse you, Robert Boyle (1627–1692)! Don’t they know that publishing takes time away from thinking deep thoughts? After all, thinking deep thoughts is the sole reason for theoretical physicists to exist. Aw well, I suppose, I must. But things were different before Robert Boyle. Alchemists were very careful about who would learn their secrets. A lot of the information was passed down orally to apprentices or written in code. After all, if you had learned the magic incantation for turning lead into gold, you did not want your competitors butting in and driving up the price of lead. But that all changed with Robert Boyle. He started the trend of publishing his results so others could build on what he had done. Also perhaps because he could not, himself, understand what his assistant, Robert Hooke (1635 – 1703), had done and thought that others perhaps could if he made the results available. Thus he published and started a trend.

Since the time of Robert Boyle, publishing has become the standard by which scientists are judged. One needs at least one publication for a Ph. D, 15 to 20 for a permanent job (in my specialty), and one very good one to get a Nobel Prize. Unfortunately, publishing does not directly correlate with how much you get paid. Now, my father cut down trees for a living and was paid for each ton of trees trucked to the pulp mill. Perhaps it could be similar with scientists: pay them by the ton of paper consumed rather than produced. At the end of the year, weigh up the paper used to publish their work and pay accordingly. A good journal would then be one that had a large circulation and used a lot of dead trees.  Of course, then you might get a bunch of really prolific writers, but a lack of deep thinkers.  And never mind electronic publication—that throws a whole new element in. Guess we’ll have to throw the paid-by-the-ton scheme out the window.

The world of electronic publishing leads to an interesting digression: What is a publication? Everyone agrees that words printed on dead trees and circulated form a publication. But what about words that never appear on dead trees? With even Newsweek becoming an electronic only publication, I guess that electronic publications must be considered legitimate. Going further, what about preprint servers like arXiv? It seems to me that arXiv largely replaces the need for the traditional journals. I always took the point of view that I would put my papers on arXiv so other scientists would read them and then submit it to a regular journal so I could put it on my CEV as a peer-reviewed publication. I also used that electronic archive as my main source of information on what was going on in my field. The archival, printed journals I rarely looked at. If we had a rating and peer-review system for papers on the electronic archives we could safely do away with the traditional journals. However, my boss does like to brag about the number of laboratory papers that make the cover of Nature.

But back to the main point, publishing is important. The first reason is that while publishing  a lot of papers does not necessarily indicate that one is making a major contribution, no papers probably does indicate that one is sleeping rather than thinking deep thoughts. Thus, papers published should be considered the first indication of scientific productivity—and a baseline for your supervisor to keep paying your or not. The second reason (and the one that Boyle initiated when he didn’t understand his assistant’s work) is that peer review, in the broad sense, plays a major role in error control. It is one’s peers that will ultimately decide if one’s thoughts are deep or shallow, on track or not. The only way one’s peers can critique one’s work is if it is published and made available. The third reason is that science progresses by building on what has gone before, and to this, we must thank Boyle. It is the published journals and the much-maligned archival journals that keep the record of what has been learned. While much that is published can safely be forgotten, the gems, like Einstein’s papers, are also there.

So if you wish to flourish as a scientist and not perish, it is best to publish—but only good papers, as to not bog down the archives or kill too many trees. As for me, I wonder if I can count these blogs as publications on my CEV. That would give me an additional sixty publications. Probably not. Anyway when I retire in a few years, I will have a CEV burning party so it really does not matter.

### Gluon Walls: A New Form of Matter?

Tuesday, January 8th, 2013

Theoretical physicist Raju Venugopalan

We sat down with Brookhaven theoretical physicist Raju Venugopalan for a conversation about “color glass condensate” and the structure of visible matter in the universe.

Q. We’ve heard a lot recently about a “new form of matter” possibly seen at the Large Hadron Collider (LHC) in Europe — a state of saturated gluons called “color glass condensate.” Brookhaven Lab, and you in particular, have a long history with this idea. Can you tell me a bit about that history?

A. The idea for the color glass condensate arose to help us understand heavy ion collisions at our own collider here at Brookhaven, the Relativistic Heavy Ion Collider (RHIC)—even before RHIC turned on in 2000, and long before the LHC was built. These machines are designed to look at the most fundamental constituents of matter and the forces through which they interact—the same kinds of studies that a century ago led to huge advances in our understanding of electrons and magnetism. Only now instead of studying the behavior of the electrons that surround atomic nuclei, we are probing the subatomic particles that make up the nuclei themselves, and studying how they interact via nature’s strongest force to “give shape” to the universe today.

We do that by colliding nuclei at very high energies to recreate the conditions of the early universe so we can study these particles and their interactions under the most extreme conditions. But when you collide two nuclei and produce matter at RHIC, and also at the LHC, you have to think about the matter that makes up the nuclei you are colliding. What is the structure of nuclei before they collide?

We all know the nuclei are made of protons and neutrons, and those are each made of quarks and gluons. There were hints in data from the HERA collider in Germany and other experiments that the number of gluons increases dramatically as you accelerate particles to high energy. Nuclear physics theorists predicted that the ions accelerated to near the speed of light at RHIC (and later at LHC) would reach an upper limit of gluon concentration—a state of gluon saturation we call color glass condensate.* The collision of these super-dense gluon force fields is what produces the matter at RHIC, so learning more about this state would help us understand how the matter is created in the collisions. The theory we developed to describe the color glass condensate also allowed us to make calculations and predictions we could test with experiments. (more…)