Pagan-Griso & Johnson

Spectrum

A discussion between two physicists on the Higgs Boson and Super Symmetry. Simone Pagan-Griso, Postdoc Chamberlain Fellow at LBNL, works on the ATLAS team at CERN. Will Johnson, a Physicist at Sandia National Lab in Livermore CA, has worked on the Collider Detector at Fermilab.

Transcript

Speaker 1: Spectrum's next [inaudible]. Welcome to spectrum the science and technology [00:00:30] show on k a l x Berkeley, a biweekly 30 minute program bringing you interviews featuring bay area scientists and technologists as well as a calendar of local events and news.

Speaker 2: Good afternoon. My name is Brad swift and I'm your host today. In today's interview, Rick Karnofsky talks with two physicists about the search for the Higgs Boson and supersymmetry at cern, Simona Pagan. Greece is a postdoctoral Chamberlain fellow at Lawrence Berkeley National Laboratories. [00:01:00] Some money first appeared on spectrum on September 23rd, 2011 you can listen to that show online at iTunes u soon after that appearance, somone moved to Switzerland to work in close proximity with the atlas team at cern on among other things, the search for the Higgs Boson. Rick is also joined today by will Johnson, a physicist at Sandia national laboratories in Livermore, California during will's Phd Studies in physics at UC Davis. [00:01:30] He worked on the collider detector at Fermi lab in Illinois. Somani was visiting Berkeley recently and we invited him and will for a followup interview. During the interview you will hear mention of GE v which stands for Giga Electron volt.

Speaker 2: The Electron volt is a unit of mass and energy head to Wikipedia for more on the electron volt. Now the interview, welcome back to spectrum. Thank [00:02:00] you. Thank you. Glad to be back. Let's get to it. A few months ago it was widely reported in the media that scientists have discovered the Higgs. Can you walk us through exactly what people found and what bearing that has? Yes. Just a reminder. We look for coalitions of protons at the very high energy in this accelerator in Switzerland, and so what we really look at these, the products of these collisions and we tried to reconstruct for what to see what happened at the very [00:02:30] smallest Cade few months ago. We helped enough data and our analysis of the data got to enough refined to be able to distinguish from the existing of expose explosive with that mass and the not existence. And so we actually found it.

Speaker 2: So that was awkward of success in the official masses and efficient mass is around 125 GV GVU is the unit information that we use for the mass. So is a roughly equivalent to the mass of a, [00:03:00] and what detector was this all? So we have two main detectors. General purpose for these kinds of searches are the large Hadron collider. One is called atlas, which is the detector I'm working on and other trees called the CMS. So both experiments had independent analysis on independent at the samples and they confirmed the existence of the heat disposal. So we had two different experiments confirming the same result, which of course is always good, right? And now [00:03:30] what's next? Now? Next, our first call is to measure more accurately the property of this new particular we found to really establish if it is fully the he exposed on or fetus any deviation.

Speaker 2: There are several reasons why we may expect some deviations, but up to now I have to say everything looks like he exposed to as predicted by the most simple theory what kind of deviations would, so you can have several things if you want precision measurement that are ongoing [00:04:00] to determine if this is really the particle we were expecting. But on top of that there is a full harder program looking for other different products of these collisions which may show deviations from what we expect. We mentioned I think last time, very briefly one today, which is really popular in the last decades, which is called supersymmetry. This is probably the very next big thing that we are hunting for. Stepping back a little bit, in [00:04:30] the months that interceded are for sharing with you and the report of the Higgs, what if any big steps in data analysis or the way that you guys were running experiments had to change?

Speaker 2: Since we talked? One big step came from data. When we're collisions that almost doubled the amount of data we had since we talked and that discovery was announced. One collision happens, but you may have multiple collision happening at the same [00:05:00] time and you need to disentangle them from what you see. A lot of work was put into actual decent tankers, these interactions, and this was really a key to be able to analyze efficiently. So enormous progress was made. Just to give you a rough ideas in our detector, one part of it try to track charged particles transverse in our detector. What you end up having are different points in different [00:05:30] layers of Europe. Sub detectors are you need to connect them to actually track the particles. So this seems easy to have one or two particle, but then you end up having more than a thousand of particles and you need to disentangle who belongs to whom.

Speaker 2: Right? So this for example is an area I've worked a little bit hard to to be able to make sure that we actually can efficiently distinguished different particles and not be confused [00:06:00] by our connecting points, which are actually belonging to different particles. Tens are there still improvements being made to the data analysis? Of course, improvements are always ongoing. We worked very hard on that. Right now the larger collider is shutting down for a two years period and on February it will actually shut down and work will be made on the accelerator itself for two years almost. [00:06:30] And we expect to be back in taking data for physics analysis the first months of 2015 and the reason we do this works not only as maintainers, but actually to improve one big thing is that we will be able to raise the energy of the collision of disc pratum's almost double it a little bit less.

Speaker 2: So right now we are working at around 8,000 GV. After the shutdown and improvements, we [00:07:00] will be able to collide protests around the 13 thousands GV. So why is that important? Increasing the energy. It actually also increased the probability of producing rare phenomenon like the he exposed in production or particular that predictably supersymmetry theory. In all this theory, the likelihood of producing such particles increased dramatically with an edge. The higher energy we can probe, the higher [00:07:30] are likely to produce those particles. And this is also because they may be heavy, even heavier than the Higgs and not only rare but also with a heavy mass and so the more energy you have the more likely is that you can produce them and what kind of work will be done besides this upgrade, what are all the staff scientists going to do with their time for two years?

Speaker 2: We will keep us busy. I'm sure the detectors themselves will be upgraded as well. The [00:08:00] trust, etc. I'm working on has a big project of trying to replace one of its inner most part. I mentioned these detectors to detect charge particles. These are based on silicon and they suffer radiation damage. With all this collision happening, we have a lot of tradition which can damage all the electronics and the censor themselves. A new detector was made and we'd be inserted in addition to the existing ones in order to improve [00:08:30] the detection of discharge particles. This is probably the biggest project which will be ongoing doing shut down for our experiment. There are also several other minor maintenance and other upgrades which are ongoing and in the meantime we easy our analysis strategy, our software in order to be ready when we come back to put in practice what you've learned, analyzing the past two years data and to be even more efficient. So with these [00:09:00] new detectors it'll be detecting even closer to the points of collision? That's correct. In fact, I mentioned things happen very close to where the protons collide. So when I mentioned that particles decay to other particles and so on, that usually happens in a small space like way less than half a millimeter. So it's important to note that you never actually see the particles you produce. You only see the decay products from them. [00:09:30] That's correct. Exactly. Having a detector which is close to where the protons collide will allow us to differentiate even better. Yeah.

Speaker 1: [inaudible] you are listening to spectrum on k a l x Berkeley. Our guests today are Simona and Pega and will Johnson both are physicists. In the next segment they discuss supersymmetry.

Speaker 3: [00:10:00] It may not be obvious, but so actually one of the main goals for High Energy Particle Physics is actually defined a single equation. And from this one equation we can drive everything we could possibly need to know about how particles interact, what particles exist, how everything works. So the goal is one grand equation, a grand unified theory right now we have a great equation called the standard model that takes [00:10:30] care of all forces. Everything we know about how physical objects interact and how they exist can be described by this one equation with the exception of gravity. We can't combine that in with this one equation. And also there's some parts to the equation that we think could be a little bit more elegant and we want to combine it with gravity and also possibly take care of some of these ambiguities. Going to supersymmetry allows [00:11:00] us to do that. So one of the big questions is we haven't seen supersymmetry yet. I know when the LHC turned on, everybody was hoping that it would just be very obvious and we would just see supersymmetry. But that hasn't been the case so far. Has there been any hints or signs that people are looking for that supersymmetry is most likely to be hiding?

Speaker 2: We were hoping to see signs of the supersymmetry in a couple of years of running of the large Hadron collider. [00:11:30] The large Hadron collider started with an energy which was slower than what is designed and only after this shutdown we will get to the energy which was designed for, so we really hope that is increasing energy, which can shed more light on the natural supersymmetry and why we didn't see it so far. For sure. The data we analyzed so far already poses a slight challenge to the theory itself. It might be good to explain why supersymmetry is such an attractive theory. People who have been looking for it for [00:12:00] 30 years now, we've seen no hints of it yet. Still very convinced. Yes, supersymmetry can explain a lot of the unexplained feature that we see up to now. Supersymmetry will give us from the practical point of view, the door to unify also gravity with the other forces.

Speaker 2: A lot of people think that this is the right way to go to be able to actually describe gravity together with the other forces in our single tier. People have already [00:12:30] heard about the string theories and so on. The all implicitly assume that supersymmetry exists in some form of it. So it's very important for us to find any sign of it or this theory, we lack a fundamental part of it. And so actually what happens if it turns out we don't see supersymmetry, the Higgs bows on looks exactly like the standard model predicts and we see no other hints of supersymmetry. Well certainly this is something that we need to consider, right? [00:13:00] There are open questions that we hope supersymmetry can answer if supersymmetry is not found still we need to answer those questions so we need to keep looking. There are several other theories which may predict and explain the same scenarios, just had not the more simple ones.

Speaker 2: So just means that probably the most simple solution we found was not the correct one. So we still need to look for other sign of it. I we do it already in parallel. So we consider [00:13:30] the possibility of supersymmetry is not the right answer. It's just the one that we think is most likely we will keep looking even if we had no sign of it, so we really expect to find some sign of something. Maybe supersymmetry may be something else, but we really hope that with the next data we will find a sign of something else beyond what we know. If that doesn't happen still we need to find a mechanism to explain what we see, which is different from what we have taught so far [00:14:00] and that for sure will require big synergy between the theoretical part and the experimental one trying to work together towards a new different solutions.

Speaker 2: There are people actively working on data from the LHC looking for other theories. Technicolor is one of the other big ones, but the detectors aren't designed specifically to look at supersymmetry. They're designed to try to catch as wide of possibilities as possible. [00:14:30] Yeah, this is actually a very good point. We perform some generalist searches which do not depend on a specific models, but just look for consistency between the given theory that we have. The standard pondered and what we see. So any hint of it can be used, at least as our guidance in watch theory can predict this kind of phenomenon. So we keep looking also for unexpected as much as possible.

Speaker 1: [inaudible] [00:15:00] this is k a l x Berkeley. The show is spectrum. Our guests are Tsimané, Pegol Rizo and Bill Johnson in the next segment. The detailed useful byproducts of high energy particle physics.

Speaker 3: Can you think [00:15:30] of any good examples of the technology developed our hundred [inaudible] physics or maybe the announced techniques designed for high energy physics and invented for it have affected people in common everyday life.

Speaker 2: This research is really targeted in fundamental research, understanding how nature works, so the effects of it are usually a very long term, so it's very hard to predict what will happen. However, the means that we use to actually [00:16:00] perform these searches, they may have a more direct impact. If we go back a bit in the history, all the nuclear science that was used to start this particle physics in general decades ago is, for example, used to treat cancer. Here in alifornia is for example, very advanced in what is called heartland therapy, so try to treat cancer with protons and they have sidebar advantages with respect to the common radiotherapy, particular for inner most tumors. [00:16:30] In this way you can reach and try to kill the tumor burden, the size of the tumor without having to burn whatever is in the meter. All these kinds of the tactful with a lot of r and d of course on top of them but were taken from what was developed for nuclear physics in the past.

Speaker 2: This is a very good example of how technology that we may use for our scope can actually be bring vented and adapted for other scopes in other very big challenge that we face every day [00:17:00] is that the amount of data we collect and the computing power we need to analyze it is huge. In order to cope with this, we had since several years our projects for distributed computing in order to be able our to analyze data everywhere using computing that are located everywhere in the world, sharing computing resources, sharing disc. This was a necessary step for us. In order to be able to carry on and having physics results. However, that can have [00:17:30] also an impact to everyday life. What we see now is our all the cloud computing increasing faster and faster in our everyday life. This is a slightly different version of this distributed computing that we've been developed and worked so far.

Speaker 3: The web as we know it today from

Speaker 2: what was created at cern. So if you actually see some of the photos of the very irst web browsers, they actually have design specifications and pictures [00:18:00] of the atlas detector at certain it was created for the scientists to communicate, but then it was such useful technology it felt to the rest of the population. So an interesting story is that even today that when you press and you don't find the page, you get these set of [inaudible] and this was actually the room at cern where the irst web server was hosted. A lot of the physics analysis that we do is [00:18:30] really from a statistical point of view, decent target. These huge amount of data that we collect and trying to find a rare phenomenon. It's usually trying to find a handful of events of collisions which have the characteristics you want among the billions that happened.

Speaker 2: So these techniques are very similar and are in common to other challenges where you have a huge amount of data and you to find a specific [00:19:00] ones on a slightly different level. But it's what Google needs to find when you put some keywords and you can find what are the relevant pages for you. And there are few. So even in this case, what you need to do is basically try to find the most appropriate few pages among the billions that exist, which match what you're looking for. In many senses, this is not very different from what we try to do. And in fact, some of the technologies [00:19:30] with very big differences are actually in common. Well, ne question of course, is with the shutdown or from your lab, do you see the need for more accelerators besides certainly I strongly think these accelerators are big and they take a lot of resources of our community, not only in terms of the money you need to build them, but also as intellectual power of our community.

Speaker 2: Run random and analyze data, but [00:20:00] having a new accelerator right now is not worth the investment in both their mind, intellectual power that we need to put on it, so the larger other collider will run at least up to the end of the Deca. Then probably up to the end of the next tech ad and this will be enough to give us data to answer most of the questions we actually build it for. Of course, people are already thinking of what's next. They're thinking [00:20:30] of new accelerators. They're thinking what is the best choice? I want to build it. If we have the technology, if we need to develop something that we are missing and people are actively working already on this and the LSE is a giant machine. It's hundreds of feet underground in miles

Speaker 3: and miles across. So building a bigger tunnel is a very, very expensive proposition. Yes. And there's just fundamental limitations on how strong magnets can be. So a lot of people are investing [00:21:00] a lot of effort into finding other ways of accelerating particles or studying phenomenon that doesn't necessarily need accelerators. Is there anything particularly promising? There's the plasma wave accelerator. Um, there's cosmic sources, so some of the highest energy collisions we get are actually from particles from outer space. And a lot of people are using the atmosphere itself as a detector. So you can look at the interactions in the atmosphere [00:21:30] and then decay particles from those interactions to see what happened. There's also a lot of work going into just looking to see if you can study these processes with a lower energy. So maybe you won't be able to see what particle you're looking for, but you'll be able to see some very slight effects on other particles or another process. Very, very slight effects, which if you're very careful and you study it, it might tell you information about these much heavier particles than you can produce. So there's, there's a lot of ways of finding supersymmetry [00:22:00] yes. Or other further beyond the standard model. Yeah. These are complimentary ways in many senses. As you mentioned, there is a lot of work on going and it's very promising, so we really look forward to these [inaudible] well, thanks for joining us. Thank you Rick as thank you Rick. Cool

Speaker 1: background [00:22:30] is archived on iTunes university. To find the archive, do a search in your favorite browser for iTunes Dash u space Calex space spectrum.

Speaker 3: We'd like to mention a few of the science and technology events happening locally over the next wo weeks. [00:23:00] Rick Kaneski joins me for the calendar. The theme for the Spring Open House at the crucible is the science of art. The Criswell is located at welve sixty eventh street near West Oakland, Bart and mission on Saturday April ix it's free from leven am until our pm the open house seeks to highlight the scientific principles, inquiry and exploration behind the industrial arts processes. Taught and practiced at the [00:23:30] crucible. Highlights include the science of fire, the gravity of mold making, mysteries of steel made visible bicycle physics. Yeah. Surfing the solar flares with science at cal recycled glass processing and more.

Speaker 4: There will be demonstrations, tuition discounts, food and bikes for sale. Visit the rucible dot org for more info. In April of wo thousand and twelve a small asteroid impacted [00:24:00] close to home in alifornia at Sutter's mill. The site where gold was irst discovered in ighteen forty eight media are astronomer. Peter Jenniskens of the Seti Institute started a tally of fines and mobilized NASA Ames research center into leading the recovery effort from the air and the ground. eventy seven media rights were found. He will summarize research results reported in a recent eventy author science article and also discuss a econd meteorite fall that happened in [00:24:30] Nevato and Sonoma last October. The presentation is Monday pril eighth at the Academy of Sciences. Planetarium. Tickets for the even hirty event can be purchased nline at Cal Academy Dot Org San Francisco Science Museum. The exploratorium is reopening in their new location at peer ifteen on Wednesday pril seventeenth to celebrate. They will offer free outdoor programming from ine am until en pm [00:25:00] the new museum offers ix galleries on human behavior, living systems maker culture, observing the landscape scene and listening as well as an outdoor space.

Speaker 4: More nformation at exploratorium dot edu also on pril seventeenth UC Berkeley is holding its monthly blood drive. You can make an appointment online but walk-ins are also welcome. You are eligible to donate blood if you are in good health, weigh at least ne hundred and ten pounds [00:25:30] and are eventeen years old or older. You can also check out the eligibility guidelines online for it and initial self screening if you are not eligible or you prefer not to donate blood. There are other ways to support campus blood drives through volunteering, encouraging others and simply spreading the word. The blood drive will be on Wednesday, pril seventeenth in the alumni house. On the UC Berkeley campus. It [00:26:00] will last from noon until ix pm you can make an appointment or find more information at the website. Red Cross lood dot Org using the sponsor code you see B. We also like to bring you several news stories that we find interesting. Once again, Rick joins me for the news and Red Alax died of cancer in ineteen fifty one but her immortal cell line called Hela cells derived from her cervical cancer is the oldest and most [00:26:30] commonly used human cell line.

Speaker 4: The cells were used to test the polio vaccine and have been used in the research of over eventy thousand scientific papers since lar Steinmetz and others in ermany published the genome of Heela and the journal g hree in March. However, the team has since removed the data from public databases because of privacy concerns expressed by family members and other scientists. Blacks did not give her a consent for the line [00:27:00] to be used and some are concerned that it may disclose genetic traits shared by her descendants. However, no law required that kind of consent in ineteen fifty one and even current regulation differs widely as to what consent would be required to sustain a modern cell line due to the extensive documentation of the cells. The privacy of the healer line may have already been broken with literature already published. Harvard medical school researchers have assembled a draft genome and [00:27:30] a team of University of ashington researchers have spoken about not only the heela genome, but also the more specific information about individual haplotypes at the American Society for Human Genetics Conference in San Francisco.

Speaker 4: A recent UC Berkeley study on the lives of wild bees find that the insects thrive better within diversified farming systems. While you might consider the insects yellow nuisances, bees actually play a crucial role in the life cycle of cross pollinated [00:28:00] crops, which account for ne hird of our caloric intake. The mysterious decline in both honeybee and wild bee populations in recent years has prompted many scientists to study the buzzing insects more closely. This study found that crop yield generally increased with wild bee population, but also linked to the recent decline in bee populations to heavy pesticide or fertilizer use. Typically in large scale monoculture agriculture, a number [00:28:30] of alifornia beekeepers seem to agree. They recently sued the federal EPA for failing to ban wo pesticides, widely regarded as harmful to wild bees and honeybees. The wo insecticides named in the lawsuit known as [inaudible] and Simon Foxen have already been found to pose an unacceptably high risk to honeybees by the European food safety authority.

Speaker 1: [inaudible] the music heard during the show [00:29:00] is by Louiston at David [inaudible] help on folk make available at creative Commons license hree point zero after music production and editing assistance by Renee Brown. Thank you for listening to spectrum. If you have comments about the show, please send them to us via email. Our email address is spectrum dot k a l xat Yahoo Dot com [00:29:30] join us in wo weeks at this same time. [inaudible] [inaudible].

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