 Good evening everyone, welcome to Southern Methodist University, and thank you for joining us for tonight's lectures. Tonight's public lecture kicks off the International Deep and Elastic Scattering Conference. There's over 250 physicists here from 30 countries here at SMU. I'm Matthew Bremer. We're both senior physics majors here at SMU, and we're glad to be your hosts tonight. So we have four short lectures in which we will learn about a question that each speaker believes is important for physics to address in the coming decades. Please feel free to take pictures, videos, and share any of this on social media. We'll save all questions until after the event, and speakers will be available to all outside for questions that you may have after the program. Our first speaker is Dr. Joseph Eisen from the University of Texas at Dallas. Dr. Eisen is a principal investigator for the UTD High Energy Physics Group. His work has covered a variety of experiments, including ATLAS at CERN in Switzerland, and the Babar at Black National Accelerator Laboratory, and the Beijing Spectrometer. In addition, he plays a banjo for a band called Squirrel Heads and Gravy, and two of his songs are on the residence album featuring songs from members of the ATLAS collaboration. Today, he will be talking about the quest to seek dark matter at the Large Hadron Collider. So I'd like to welcome Dr. Joseph Eisen to the stage. So I'm going to be talking about hunting dark matter at colliders, and this is an area where particle physics got informed by astronomy and astrophysics, and I was pulling out pictures of my telescope, and I realized, hmm, Steve Secoula, who will be speaking later, had some old family pictures, so I went back into the archives and I found a picture of my telescope when it was new. How many of you have something which is 40 years old still that you can still use? For me, that's my telescope. So I'm going to be speaking about the universe of dark matter, and so here's a history of the universe, and the big banning happens here, and in the first fraction of a second, we go through all the things you hear about quantum gravity and string theory, grand unifying theories, as the universe quickly pooled and expanded into a period of rapid growth that we call the period of inflation, and after the period of inflation, things are starting to get more like where we used to in our current universe, because things are cooling down. In the early universe, all of the four forces that we know about, gravity, the weak force, the strong force, the electromagnetic force, we're all about the same strength when they're hitting particles that are moving very, very fast. But as things slow down, first gravity throws out and became weaker, and then the strong force separated from the electromagnetic force, and by the time we're more or less fully expanded, it's going to be the universe is filled with quarks and gluons, in what's called the quark gluon plasma, sort of a soup, and then that cool down, and protons and neutrons start to form, and at the edge here, where it says afterglow, that was a very important event in the history of the universe. That's when electrons were grabbed up by protons and atoms formed, and that's the beginning of the Dark Ages, a period of about 400 million years, when there wasn't any life in the universe except the little leftover pangs of light that the electrons gave off as they fell into the protons and to form atoms, and there was a little bit of UV light, and that was all there was in the universe, for just about 400 million years. It was a very dark, faceless, very uniform, but not perfectly uniform place. And so the atoms were about 12% of the universe back then, and that ultraviolet light eventually would be called the cosmic microwave background, and as the universe expanded, everyone seems to be moving away from the atoms again and more, and they're now microwaves, and that's when you hear the cosmic microwave background. That's where it came from. But there's something else in the universe back then, which is overwhelmingly the single largest constituent, this dark matter. Why is it called dark? Well, in order to see something, you have to be able to shine light on it, and the light has to be reflected. But dark matter has no electric charge, so it doesn't reflect light. It doesn't absorb light. It doesn't scatter light. It's as transparent as you get. You can't see it. And it has no color or strong charge, a force which is what it would need to be attracted by the force that holds protons and neutrons together. So basically, it's not there. It behaves in a sense like the neutrinos that we know of. And the one thing we know about dark matter, the way we know about it, is that it does have mass, and that's important. And all of this dark matter was left all throughout the universe, but there were places in the universe which were denser, the remnants of quantum fluctuations during this period of expansion. And dark matter started to cover less. It started to fall to places where there was a little bit more density than elsewhere. And it fell, and it fell in excessively. But this is how we know that the background was not uniform. This is the microwave background as we see it today. And if you look at the scale, it's very, very minute variations in the temperature of the microwave background is what's represented by these colors, slightly different colors on this globe of the sky. And so this is a snapshot of those primordial quantum fluctuations that the dark matter fell to. And so for over 400 million years, dark matter fell and it gravitated in the coalesce. And when the dark matter gathered, some of the ordinary matter, the hydrogen and helium gathered and the clouds became denser until the nuclear furnaces turned on. And this is not the early universe. These are modern pictures of areas in the sky where new stars are being formed on the left of the clouds. This is something like what the early universe must have looked like. After 400 million years of being battered, it was now a beautiful, spectacular place. And not only the stars formed, there were galaxies forming. This is a region of a galaxy where there's a lot of new star formation, help that color. And so if you look at where the galaxies formed, now we can look back into the sky. This is from the Sloan Digital Sky Survey. We can see that there's a pattern that the universe isn't uniform, matter condensed, wherever there have been quantum fluctuations. And so this is the sky as we see it looking out at the slices of the sky because we haven't done the whole sky in a while. And so that was the role of dark matter in attracting visible matter. And that was where things were. When did the Heidi and Lorke of 13 billion years until 1933 when a Swiss physicist named Fritz Zwicky was doing an exercise, he was looking at a cluster called the Comber cluster, in Comber, very easy to say if you are an amateur photographer, you know where it is. And he was looking at the cluster, and he was going through an exercise that, I know there are a few physics students in the audience, but he was applying the virial theorem to the Comber disease. And if you measure the velocities of the particles, it should tell you the mass of the cluster. Well, he got the wrong answer by a lot. And the answer, I shouldn't say the wrong answer, he actually got the right answer. It was just not the answer that anyone expected. And he was sort of a curmudgeon. People sort of did something wrong and that of all can't be right. And I went on. And then in the 70s, another physicist named Vera Rubin set out to measure the speeds of stars orbiting about galaxies. And so this is done, for those of you who have ever heard an ambulance go by, with a high pitch, going to a low-pitched sound, that's a doppel shift. And it works with light as well. So you put your spectrograph across an edge on a galaxy, and you can see the shift in the frequency of the light, and that tells you whether stars are coming to you or away from you, and how fast. And Vera Rubin, well, what everyone was expecting is something like we see in the solar system, where you have a sun in the center and then the speed falls off with distance. Well, that's what everyone expected. You'd expect to see something like that for a galaxy to possess that bulge in the center where all the mass, a lot of the mass of the galaxy is. But that's not what Vera found. The speed gets faster as you get further from the center. And this was a head scratcher, but it wasn't a mistake because the same result happens for all galaxies. And so that's the best thing. Hey, we're missing a lot of the mass. There's some mass, but we know where the stars are. We know what the gas is. There must be something else. By the way, this happens in the Milky Way too. The Milky Way is just like the other galaxies. So notice anything strange in this picture? See those funny shapes? That's gravitational lensing. And it's another way to measure the mass of a cluster. This is a cluster of galaxies. And you see that these shapes are a way to measure where there's mass in the galaxy. And when we do, we see this cluster has this funny ring of mass and we believe that's because there was a collision of clusters of galaxies. And as the animation shows, when you have clusters colliding, it separates out the dark matter from the visible matter. And so we can see the clusters of galaxies, these yellow things in the center, but here's this closely yellow dark matter. So dark matter is real. We make it in an accelerator. Because I am an experimental physicist. And so we have a clue from a bunch of satellite experiments as to how we might make dark matter. Because when we're looking at the cosmic ray spectra and looking at anti-electrons, positrons, the expectation was that as you go to higher and higher energies, you see fewer and fewer. And when we get up to higher energies, the number of positrons, the fraction of positrons increases. And that's another edge scratcher. Is that a clue? Because positrons don't get very far. They're anti-matter. So they have to be made locally. What's a local source of anti-matter? Well, anti-matter, high energy gamma rays have the property that they can pass any matter and convert it to an electron-positron pair. And some of the subjects suggested that perhaps amongst dark matter particles is a force between dark matter particles that has a photon-like equivalent that somehow can mix. It's all speculative. But this is what physics is like at the edge of what we don't know. If that dark photon turned into an ordinary photon, it would have a signature of an electron-positron pair or heavy cousins. And that's the signature my room at UT Dallas has been looking for a long time. The short answer is, we have not seen them so far. We have looked. If we had seen them, I wouldn't be talking to you. I'd be talking to an audience in Stockholm. But in any event, we're about to run the LAC again. We're going to come back along with a higher beam energy and an improved detector. And hopefully we'll be reading about discovery before we go through the wall. Thanks. Thank you, Dr. Eisen. Our next speaker is Dr. Pat Scubick from the University of Oklahoma. He also conducts research using the Atlas experiment at CERN. He has interest in experimental elementary particle physics at the energy frontier, proton collisions, and the development of semiconductor detectors in high-energy physics experiments. He has made several contributions to creating these semiconductor detectors. Dr. Scubick will tell us more about the search for deeper symmetries in nature than those already discovered. Please welcome Dr. Scubick. Thank you very much for the introduction. The microphone working. Hopefully it is. Well, it's a great pleasure to be here. And so I've been asking myself the question if the universe is in the answer, what is the question? The question I've been asking myself is, is there physics beyond the standard model? And that's similar to Joe's question. So if we remove the slide, okay? So the standard model has particles that are part of it, particles that make up matter, which are the quarks on the left, times on the left, and particles that mediate the forces like the proton, glubon, W and C, and of course the Higgs, we now believe, exists and it provides the other particles with masses. So these are the particles that make up all the matter that's familiar to us in everyday life. And we have atoms, molecules, of course the proton, we believe consists of three billions quarks and glubons hold those quarks together and then the proton combines the other nucleons to make up nuclei. So how do we study these particles? Well, we smash them together and we study the debris that comes off from the collisions. And actually the proton is a little bit like a car because it's fairly complicated. It has these quarks and glubons in it and so when we smash them together, which we did at the LHC, we smashed protons together, we see fairly complicated events which contain a lot of debris, some of which may not be interesting, some of which may be interesting. So that's what the field of energy physics is all about. So what do we conclude about the Higgs that we just discovered? Well first of all we know its mass quite well, a little over 125 GED, all the cross sections that we measured are consistent standard model expectations. So it appears to be exactly the state that the standard model predicted. Of course we'll be studying it much more in the new run as it starts to summer. But while the standard model is quite successful, it has important limitations. First of all in my mind the biggest limitation doesn't include gravity whatsoever. So there's also no candidate for the dark matter that Joe was talking about. And another technical problem is that the Higgs mass would not be stable due to virtual quantum corrections as indicated by the diagrams here. So I think it's a bit embarrassing that we don't have the quantum theory of gravity, we have a classical theory of gravity and that's been known for 100 years. In fact this is the 100th anniversary of Einstein's general theory of relativity. And we know gravity exists by step off the stage. I know I'm not pointing to the meaning of the straight line which just got covered up here, this picture from Science Macy. Instead space-time is going to be worked by the presence of the Earth and I'll be moving in the direction of the Earth by step off the stage. So how can we incorporate gravity into our theories? Well fortunately several decades ago an extension to the symmetries that underlie relativity theory was discovered. And this is called supersymmetry, or SUZI for short, and this requires a symmetry between the matter particles and the force particles. So for every particle in the standard model there should be a supersymmetric partner. And after putting those superpartners in then the bad quantum corrections I mentioned cancelled and are no longer a problem. So if this is true for every particle in the standard model there will be a supersymmetric partner. And we give these supersymmetric partners names we put an S in front of the name of the particle if it's a matter particle so that a squirt superpartner would be a squirt, a squirt superpartner would be a squirt. And then if it's a force particle we put an Eno at the end of the name so the superpartner of the photon would be a fotino. And the superpartner of the Higgs would be a Higgs Eno. But nevertheless if this theory is correct all these particles should be out there in nature. And what does the Higgs mass tell us about supersymmetry? It turns out that for supersymmetry to be viable there's a fairly narrow mass range where the Higgs goes on to be live and it turns out that it does lie in that narrow mass region labeled MSSM. Whereas if you just take every kind of standard model by itself the range of possible Higgs masses could be much wider. So maybe this is a clue that we're on the right track thinking about supersymmetry. Well once we specify the parameters in the theory we can calculate exactly how these particles will behave and how they will interact with other particles and how they will look in our experiments. So here is a simulated Suzy event and how it would look in the Atlas detector. So we have charge tracks that leave tracks in the tracking system we have lots of energy deposited in the outer parts of the detector indicated by these yellow bars which are proportional to the energy deposited. So this is the beam's eye view this is the beam that's coming right into the page right in the center of the detector. So that's the beam's eye view through the vent. If you look at it from the side it looks like this and here we see we have some muons coming out into the outer muon system and lots of energy deposited in the calorimeters. So we can compare our data to the events predicted by the standard model and if we see any excess we can use these simulations to determine whether Suzy particles are the excess. And our group at Oklahoma theory group has been pioneers in developing the code necessary to make these displays. So far we've looked very hard for these extra particles and so far we haven't seen them. So is that a crisis or could there be an explanation for why we haven't seen them yet? Well it turns out there are a couple possible explanations. One is that we just have enough energy to produce these super partners and that we need a bigger accelerator. Or it could also be possible that the particles decay in such a way that they don't leave signals in the detector. We expect that the lowest mass super symmetric particle would probably be stable and it would leave the detector without leaving any trace. So that particle would be an excellent candidate for the dark matter that Joe was talking about. But if the particles have a spectrum so that the particles that are slightly higher in mass than the live in the smallest mass one might leave very little energy in the detector if the mass is very similar. So those are two possible explanations and in fact to take into account the value of the haze mass actually a spectrum that looks like this is actually quite possible. And here we have low mass super partners around 100 GV or so that have very similar masses to each other. The haze and haze nanos for example might decay into just dark matter without leaving any real signal in the detector. Now we may be able to see some of these higher mass states if they exist. Maybe you want to teach me a solid mass but we probably will not see the we will not see the particles up here the higher masses because they're simply too heavy to be made in the LHC. So what are the future prospects? Well we have as I said may not be able to discover super symmetry at the LHC and it will not cover all the parameters space so it could still be out there even if we don't discover it. I'm actually erotically avoided a super collider that was under construction right down the road in Texas here would have had a lot more energy than the LHC and would have covered a lot more than the parameters space. We'd love to have that machine today. But maybe we can make other new machines if we don't see anything. One possibility would be to build a machine with electron positrons as the fighting particles and they would be more cleaning events and they would possibly be able to detect these low mass oops, sorry these low mass particles that I mentioned that we could maybe are not seeing at the LHC because of the compressed spectrum. So there's a proposal out to build such a machine and actually Japan is very interested in hosting it it would have an energy between 250 and 500 GB it's called the International Linear Collider or ILC and it would have as I said cleaner events where you could detect these compressed hexagons. So the Japanese are considering it it's cost about $10 billion so contributions will be needed from other countries including the United States. Here's an example of what an event would look like a Targino event at the LHC this was provided to me by my theory colleagues and you can see the topology of the event is relatively simple. And then on the right you see the city traveling on its way to a Japanese city and looking very much like a bullet train. So in some way if supersymmetry is discovered it would gain and move us to the next level in understanding unification of the laws of physics would provide a dark matter candidate it would also be an avenue to include gravity in our theories and maybe a window to superscream theory. An immediate crisis would be averted and here is a picture of a quote unquote in the Susie event as seen by the Albus detector. I'd like to thank the other members of our group for contributions to this talk in particular the theory members as far as up-to-date neck how we bear it was in the audience and chunked out. Thank you very much. Thank you Dr. Skivak. Our next speaker is Dr. Chris Jackson from the University of Texas at Arlington. Dr. Jackson specializes in theoretical high-energy physics he has been the lead author on several publications regarding the precise predictions of Higgs boson production rates at LHC. This will help us understand the complete nature of the newly discovered particle. In addition he has developed novel ideas concerning dark matter. Today he will talk about dark matter and how particles from space can help us figure out what dark matter is. Let's welcome Dr. Jackson to the stage. Can you guys hear me? Yes, okay good. Alright, so thank you. So I want to thank the organizers for inviting me. Like the introduction said I'm a theorist so I'm kind of like the thing on the Sesame Street. I'm the one that's not like the others. And so I come from a different point of view some might say totally old and in reality. When I look at physics, when I look at dark matter but I hope to give you an idea of the things that we think about as theorists and some new exciting ways that we're looking at to detect dark matter. So I have to thank Joe and Pat for a very nice introduction to my talk and so my slides are going to kind of seem like maybe dark matter for dummies or idiots got into dark matter but that's what they are, okay? So what I spend most of my time about what I spend most of my time doing is trying to think what is dark matter. Most of the time I'm scratching my head. Sometimes I'm banging my head against my desk. But the unfortunate thing is I can't tell you what it is but I can't tell you what it ain't. And so this comes from measurements that Joe was talking about things like gravitational lensing and things. So you're asking the question what can dark matter be? The most logical thing would be it's got to be something big. It's got to be something that we know. So it's such as brown dwarf stars so things like big Jupiters, neutron stars or maybe gargantua from interstellar movie, right? So giant black holes. But we know from these gravitational measurements, gravitational lensing measurements that these things are there. We know they're there but there's just not enough of them to make up what we, you know, what makes up about 20% of the universe, right? And this stuff goes by the acronym of massive compact halo objects or machos. And so the next question you could ask, you know, after this is, well, maybe, you know, maybe it's not something big. Maybe we screwed up or we don't understand the laws of gravity, right? To explain these rotational curves and things like that. It turns out that that is not true. We've shot that down. Those ideas, those are called modified Newtonian dynamics. So those alternate theories of gravity are gone, right? And everything we have now seems to point towards dark matter being a particle. And you guys have seen this picture a couple of times. These are the particles that we know about. These are the standard models. This is like your periodic table of particles, if you will, all right? And everything that we know of is made up of all this stuff, except dark matter and maybe dark energy, right? And everything in this room is basically made up of this first column, okay? So the ups and down, quarks make up the protons and neutrons and the electrons obviously are present. But so you ask yourself, well, you know, if these are the particles we know about, could dark matter be one of these guys? And as Joe highlighted, we know that dark matter is electrically neutral, right? So if it doesn't interact with light, otherwise we would see it. It's not weak. It is weakly interacting. It doesn't interact through any other strong force because if it did, we would have detected it, right? So we hope that it's weakly interacting. That's kind of the hope of theorists. And the other thing is that it's extremely long-lived. So as I pointed out earlier, the abundance of dark matter that we had was born in the Big Bang. So, you know, 14 billion years ago, right? And it turns out that when you, you know, use these three characteristics, or these three constraints, that nothing in the standard model can play the role of dark matter, right? The closest you can come are the neutrinos, because they're extremely long-lived, weakly interacting, weakly interacting and electrically neutral, but they are ultra-ultivistic. They're moving at very high speeds, and so you can't get these beautiful pictures of these large-scale structures. So you don't have time in the universe for neutrinos to act as your kind of gravitational wells. So that all points to a new particle, right? And you say, well, okay, so that's a new particle. We have to go, what's called, beyond the standard model. And you say, okay, well, are there theories of, you know, dark matter? Can we come up with theories? And the answer is, oh yeah. Okay? So the good thing about energy physics for theorists is that these experiments take years and years and years to build. They take years and years and years to run. They take years and years and years to analyze the data. And that gives theorists, you know, just, you know, sitting in a Starbucks somewhere down in Espresso with the laptop to come up with all kinds of crazy ideas. Okay? The bad news, or the good news, depending on your point of view, that it might be bad news for some experimentalists, is that we can come up with a whole boatload of theories, right? And this is just a cartoon showing a bunch of different theories and, you know, maybe like a Venn diagram from hell. But it shows this kind of pink overlap region here that's showing that all these different models basically lead to the same types of cycles, right? And so you ask, well, if we could discover it, how are we going to tell them apart? Well, we're going to push that question under the rug because the first thing we want to know is can we detect it? That's what we want to start out with. And the one thing we know for sure is that it's everywhere, okay? And Joe showed a similar picture to this. This is from theoretical simulations, but you see these large, these are what they call large-scale structures. So this is on the scale of the universe, and these are clusters of galaxies, and they form these filaments and voids and all kinds of stuff, okay? But the important point is dark matter is everywhere, even in this room, right? And so you say, wait a minute, dark matter's in this room, why can't I feel it, right? And it turns out that dark matter, there's billions of dark matter particles passing through your body every second. Every second, right? But it's so weakly interacting that it just goes right through you, right? So you're sitting in this cloud of dark matter, and this is going right through you. Well, some people did a study based on some experimental constraints on dark matter, and they did a calculation to see how many dark matter particles actually interact with the nuclei in your body. And it turns out that, you know, that number is typically on the order of a few. So you get a few dark matter scatterings off of your nuclei every year. But it could be, you know, in a more optimistic scenario, it could be up to, you know, 1,000, maybe 10,000. But the important point is you don't have to worry about dark matter radiation, like you don't have to worry about turning from these cosmic rays, you know, these dark cosmic rays or anything like that. Okay, so what do we do? Well, we can try to produce it, like Joe and Pat, right? Or we can use the fact that dark matter is all around us, right? And that's the idea of these experiments that they put underground, and they just wait, right? They put those things down there, and Dr. Cooley... Way back there, right? As an expert on these, as they put a detector underground, they just wait for dark matter to come in and scatter off of their detector, right? Or the third possibility is you look to the sky, right? You look to the sky where you expect there to be a lot of dark matter. Because it's weakly interacting, you don't want to try to look in this room, because it will just be waiting forever. So you look in places where there are very strong gravitational wells, right? Where gravity is very strong. And so one example might be the center of the Milky Way, right? So there's a lot of matter there. There's a supermassive black hole there. So there's a lot of gravity, right? And so you would expect a lot of dark matter to fall into this well. And if there's a lot of dark matter, that means the density is high, right? And there's a higher probability of dark matter to scatter off of each other. And if it can scatter off of each other, there's a possibility of sickness. Okay? And not only, you don't have to look as far as the center of the galaxy, you can also look closer to home. So the sun is obviously a strong gravity, gravitational potential, or gravitational well. So you could expect some dark matter to accumulate in the center of the sun. And you could actually, you know, imagine scenarios where dark matter is caught up in the gravitational well of the earth, right? So what do we look for? We're looking at these places where there's a lot of dark matter. We look for dark matter annihilations. It sounds cool, right? But what is it? So it's like Pat was saying, that every particle has this antiparticle, right? And so you apply the same ideas to dark matter. And so you look for these types of events. So you have a lot of dark matter that you can interact in. So there's a higher probability that it will interact. And if it has its own antiparticle, or if it has an antiparticle, it can annihilate, right? And so you're using E equals mc2, right? But in reverse. So these guys are just sitting out there and you convert their mass excuse me, convert their mass into energy, right? And that energy can be converted into the mass of lighter objects, works and bosons. And energy. So these guys will be boosted. They'll be given a lot of energy. And so they can make their way to our detectors. Just a funny story because they pointed out that Howie bears in the audience. And Howie was my, I'm with the grad school floor of state and Howie taught me everything I know about quantum field theory. But in your first semester of grad school they make you go to the colloquium, the departmental talks. And so the very first one I think I went through Howie was given a talk and he was talking about supersymmetries, one of the world's leading experts. And he was talking about electrons and smuons and all this stuff. I had no idea, I didn't know I wanted to go into particle physics. He was talking about smuons and spotting and stuff. And all I could think was, wow, this guy has a really bad list. I'm a little, little did I know that I would go into this field and I would be the one saying smuons and electrons. Anyways, so we're looking for dark matter annihilations. How do we look for them? Well, we can look for gamma rays, high energy photons. And the way we do that is so dark matter is annihilating and annihilates into the photons out here, these wiggly lines. Those would occur, say, at the center of the galaxy and they make their way here and we would detect them in space with the Fermi Gamma Ray Telescope. So this is one of the ongoing experiments looking for of many things that's looking for dark matter annihilations. And you say, what would it look like? Well, this is a picture from the Fermi Gamma Ray Telescope that shows the plane of the Milky Way in gamma rays. And you can see it's mainly located in the plane of the galaxy. You see these little dots here and there. Those are neutron stars and things like that. But you're hoping to see that once you subtract off the normal astrophysics, you might see some signature of dark matter annihilations. The other experiment that I really like, that I think is really cool is an experiment called ice cube. This is an actual picture of it. It's not the rebel base on Hoth, even though it looks like it. But this is a really cool experiment that Dr. Cooley also worked on. And what they do is they're in Antarctica and they drill down using these hot water drills and they sink these detectors, these strings of detectors down in the ice. So they use the ice cap as the detector itself. And so what they look for are signatures of neutrinos coming from different sources but one of them is possibility coming from dark matter. So this is a picture of an actual event an actual event passing through the strings here and so you can see the little circles of the detectors themselves firing off. So we hope to see something like that coming from either the sun or some cosmic source. So I just want to end with just a statement because when the Higgs was announced that it was discovered a lot of the media made it sound like that's it, particle physics is done fold it up and let's go home and it's not. The discovery of the Higgs is just to begin. It's just the tip of the proverbial iceberg. So now we know kind of a complete picture of the 5% of the matter that we can see but there's all this stuff beneath the surface that we hope to discover and study in the next few years. So thanks a lot. Thank you Dr. Jackson. I always wondered why the ice cube experiment was in Antarctica. I think it's amazing dark matter particles are passing through us every second. Do you know how it tastes like chocolate? Alright our next speaker is Dr. Sikula from here at SMU. He's also my research mentor here so it's a great pleasure to introduce him to you. Dr. Sikula has studied the quantum numbers of the Higgs boson and contributed to searches for additional Higgs bosons like the charged Higgs. He's also interested in dark matter and as an award-winning teacher here at SMU. He's also a leader in the Higgs experimental physics community. Today he will talk about his journey to understand forces and particles at the beginning of time. Thank you very much. Make sure that this is on. One of the things that's very important to me is family. You can think of family quite narrowly in terms of the people that you may go home to at the end of the day or the people you hang out with at family reunions or holiday feasts at various times of the year. I'd like to be a little bit more inclusive than that. If you think about all of us tonight we're all part of this shared human family with a lineage going back hundreds of thousands of years to all the ancestor humans that came before us. In a much wider sense we're part of a great cosmic family. The atoms that make up our bodies are made from particles that have essentially been with us in one form or another since the beginning of time 13.7 billion years ago. And so the theme of my presentation tonight is to think about the journey that physicists take through the cosmos by asking it questions and then having the hubris to expect answers back by doing experiments to sort of get back to family photos of the cosmos at the beginning of time so that we can better understand ourselves now and in the past and maybe understand something about where we're going in the future. So this is Jacob Haskell Thompson. I knew him as Papa. This was my grandfather on my mother's side. And you can see a picture of him crouching in his basement workshop in his home in Maryland. He was a World War II veteran. I never much talked about that part of his life until far later in life. But he was also an engineer by trade and when he retired he was an electrician and used that basement shop quite a bit more. Now that shop was full of dangerous toys that I was not allowed to play with and I could never go into that basement shop unsupervised. And so for me it was a place that was important to Papa but I didn't really understand that place. All I knew was that mom and dad didn't want me going down there and playing when no one was around. Well, I came home from school by day in 1990 and my parents were waiting for me at the end of the driveway, not 10 feet from where the photograph of me and Papa was taken when I was very young. And they told me the news that he had died that morning, very suddenly, died on breakfast table, basically of a stroke. It was a shocking death. Nobody expected Papa to be the first grandparent to die in the family. He seemed to be the most vibrant, the most healthy, the most everything. And so the family in the wake of this terrible news was essentially crushed to the point of not supervising the children in the family. And so in the weeks and months after Papa's death, I spent a lot more time wandering down into that basement workshop with all of his dangerous toys and nobody seemed to much mind anymore. And that shop is in fact still there today where my grandmother still lives, essentially the way it was when he died after my father did some tidying up and organized it a little bit after. I found myself spending a lot more time in that basement shop. I burned myself once and I electrocuted myself twice. And by doing things like that, by getting my hands into radios and other gadgets that Papa had in the basement, I learned to not only take them apart, but lose my fear of putting them back together and worrying that they wouldn't work anymore. Now you could put them back together and they would still work and sometimes they were broken and you could fix them. So, even though I didn't get to know Papa all that well in life, I was only a freshman in high school when he died, in his death I spent more time in a place that was important to him to try to get closer to him, to try to learn more about Papa than family photos and an old album to tell me. And in doing that I lost my fear of tinkering with the cosmos. And in part in death, Papa made me into the experimental scientist that I am today. And so while he didn't live to see me graduate from high school or college or earn my PhD or get my faculty position at SMU, he was instrumental in me becoming the scientist that I am today. And much as we can learn about a family member from photos and then interacting with members of our family to learn more about them, we can also ask questions of the cosmos by using experimental science and try to get answers back about what the cosmos was like when it was very young. So if you imagine that 13.7 billion years ago when no human beings were around, there was this moment where the universe came into being. You would really like to know something about that moment in time. I mean after all, everything that happened from that moment onward influence everything in the cosmos and where we are today, who we are now and what the fate of this universe ultimately is. So by gathering information about the past, we can gain not only wisdom, but also the ability to control the world around us and understand it a little bit better, maybe lose a little bit of that fear that we have about the universe. So the question that gets me up every day and coming into the office with all the stuff that is associated with an office job, all the stuff you don't like because of the kernel of the thing you do like. The kernel of the thing I do like is the question. And the question that's been on my mind since 1991 when I realized that I had a love of physics. And that is simply what were the building blocks and the forces that were present at or near the beginning of time that ruled the cosmos. And right now from my perspective as an experimental physicist working on the Large Hadron Collider and especially working with the Higgs boson, which was newly discovered I am particularly interested in understanding what the Higgs boson can tell us about a moment in time that's maybe 400 millions of a millionth of a second after the beginning of time. So to do this, to study particles that were around and playing big roles near the beginning of the cosmos, but which are very hard to see now and to see the role that they play in our lives now. You have to have a machine. And the machine that's been mentioned time and time again here tonight is the Large Hadron Collider. There is no such thing as a time machine, at least not yet. And so we can't hop in a time machine and try to go back and see what those first moments of time are actually like. But we can recreate them in miniature. And so the Large Hadron Collider for a particle physicist like me is a microscope. It lets us see and create and study the smallest building blocks of nature that we can summon now. And in many ways it's also a time machine. In the same way that kind of getting your family together every year for a reunion is a way of seeing the history of your family laid out all in one moment. The Large Hadron Collider smashes together protons at such energies that it essentially recreates a moment in time, about a hundred millionth of a second after the creation of the universe. So this is a view inside the Large Hadron Collider tunnel that's 17 miles around. And what you're seeing here are one of 1200 of the most powerful magnets that humankind has ever constructed. And their sole purpose is to keep something of the order of several hundred trillion protons going around in a big circle. That doesn't sound very impressive. But the idea is to get them up to within about 8 miles per hour of the speed of light and then try to smash them together. A hundred trillion protons on another hundred trillion protons. In the hopes that one or a dozen or maybe 45 of those pairs of protons will smash into each other and annihilate one another. And the resultant's fireball is a little bang. It's a little burst of energy that represents a moment in time a hundred millionth of a second after the beginning of time. And if we can photograph those moments in time we can build up a family photo history of what the universe was like when no human eyes were there to see it in the hopes of understanding what were the building blocks and the forces that were playing the dominant role that the time Large Hadron Collider can recreate. Well you need a camera. If you're going to take pictures you need a camera. And this is my camera. Sorry it's not my camera. I mean I share it with the three thousand other people. There's only really one light in the world. I mean technically there are two big multi-purpose cameras at the Large Hadron Collider. But Atlas is unique in its scale. It is eight stories tall it is half a football field in length. And unlike the mobile phone camera that can be stamped out of a factory like a toaster for you to buy on a payment plan from a telecommunications company you know that thing can maybe take 240 pictures per second of high definition quality video with you know pixel resolutions of up to maybe 12 million pixels. The Atlas camera in contrast is a 100 million pixel camera capable of taking 40 million pictures per second. That's an incredible achievement and that's why there's really only one or two things like it in the entire world. And this thing has to run nine to ten months out of the year 24 hours a day while the Large Hadron Collider is operating and it's going to do that over something like 20 to 25 years. So this thing has to work and it has to work all the time and really well and that's why it takes a huge group of people not only to make it happen but to keep it going and make it better. Alright well this is an example of one of the photographs that we you know study. We don't do it this way we don't do it with our eyes. We write computer programs that break this down and do things businesses can talk about like energy and momentum. And we build up a picture by all the stuff that sprays into the camera we work back to the center where the proton-proton collision happened and we try to figure out what stuff was made at the moment of the collision and is it stuff we've never seen before that's so rare that you'd only lay eyes on it with enough energy and enough proton-proton collisions every second. This happens to be a photograph of a very good candidate for a Higgs boson. It has evaporated its energy, its mass energy has converted into other things. Those are the things we see but thanks to hundreds of years of understanding nature using the laws of physics we can work back to what happened at the center where the protons collided. Now we don't keep 40 million pictures per second do you keep every photograph that you take I mean for instance here the photographer was clearly trying to get a lovely photo of these three friends or family members or something like this and this idiot jumped in and photobombed it at the last minute. We all have a cousin or a best friend who does this sort of thing right? In many ways all the physics that we already discovered all the particles we already know about the low-hanging fruit in hindsight that was easy to discover that's the stuff a large electron collider makes all the time. When you smash two protons together you get the whole record of all the easy discoveries you ever made before and you made somewhere in there are the new ones you're really hoping to find and so we don't keep every picture either we whittle down 40 million photos per second to maybe a few hundred interesting ones per second that can get distributed all across the globe and analyzed by physicists looking for various things including more information about the Higgs boson. So if you would ask me about three years ago what did I think as an experimental scientist the family photo looked like for stuff to go into the lab and run the reunion and reliably study. I would have shown you a picture like this much like the ones that you've seen earlier tonight there are the quarks and the leptons and as we said by Dr. Jackson in the previous talk all you need are the ups and down quarks and the electrons to make all the atoms that make us up. All this other stuff played a much more important role near the beginning of time and without it the universe wouldn't be the way it is today. These are the common things you run into like charmed quarks and top quarks and things like that. They are essential in why the universe turned out the way it did. As far as we know there are four forces three of them we can describe as being carried by particles and that pesky gravity problem is a real challenge to physics that everyone says will be solved in 20 years and we'll see what happens in 20 years and there was a rumor a story in the family there was a rumor that there's another particle out there that you needed in order to give mass to give substance to all the other things that have mass or have substance and that thing, that rumored thing was the Higgs boson, the Higgs particle so it's like, you know, great great great great great uncle Peter who's rumored to exist but no one can find a family photo of this guy and then one day you happen to go through enough photo albums and you find some person you've never seen before in a family picture and that's essentially what happened in 2012 when the APHIS collaboration and the CMS collaboration co-announced the discovery of a new particle it took a whole other year of work just to nail down its properties enough to be convinced that it's probably very likely the Higgs boson so as a result of the mathematical work that they did with colleagues in the 1960s from Swann and Blair and Peter Higgs so great great great great uncle Peter I guess over here they received and shared the Nobel Prize in 2013 for their essential contributions that led to the discovery of the Higgs boson in 2012 they did their work in the early 1960s that's a long road to travel so if you were to ask me what I think the family photograph looks like I would say, okay it's not a rumor anymore I really think the evidence says that the Higgs boson is a real thing and we've only just barely begun to scratch the surface at understanding this particle and its role in the great family photo so if you heard about great great great great uncle Peter and then stumbled across one photograph of this person would you be satisfied just knowing what the person looked like and then be done with your quest to understand this family member? would anyone in here be satisfied? probably not you'd probably take that picture and go from family member to family member do more work you want to understand who was great great great great uncle Peter when did they live? but what did they do? why does nobody really seem to know what their life was like? is this a whole other branch of the family that we would like to understand more about our rich family history and so I would say that my biggest hope is that as we continue to study the Higgs particle now that the Large Hadron Collider has gone through an upgrade and we're going to get even more collisions at a higher energy than we've ever had before we'll not only make lots more Higgs but we'll be able to discern their exact properties with much more clarity than we could from the first two years of data that we had from the Large Hadron Collider in a multi-decade program to understand this particle that now in many ways sits at the center of the focus of our family photo my hope as a physicist is that it won't just be the Higgs particle that we study alone I hope that there will be a whole bunch of other things maybe relatives of the Higgs particle heavier Higgs is a bit of weird or strange in some way compared to the one predicted by the standard model of particle physics dark matter has got to get mass from some place if it has mass and it doesn't get it the standard model Higgs particle so I'm hoping that we'll find a whole new family tree a whole new branch of the family tree that tells us about where mass comes from for things outside of the standard model of particle physics so my big hope that I'll leave with you tonight is that all of us retain the curiosity that we had as children and we use the life experiences that we go through to develop in a particular path that's of most interest to us I became passionate about physics and understanding physics in 1991 through a series of events including Oddly Enough to Death for Papa that was one thing that set me on the path of being a physicist but one thing that's essential to never lose is the curiosity that drives you to ask questions do the hard work to try to get the answers and then actually have the hubris to expect answers to come to you at some point from the universe that's how you make discoveries and that's what all of you should go out tonight and try to do, ask questions and go find the answers thank you very much thank you Dr. Sikula, that was a great story about discovery so we had quite a few good talks tonight and they were about these interesting questions about future physics so I hope in coming years we will be able to answer some of these questions so I'd like to invite all of our speakers tonight to come back up on stage please we would like to let's thank our speakers again for having such a great time we have a few presentations to make I know I'm taking a photo of them so Professor Eisen, thank you I'm probably going to get paid for this job wow wow that's it thanks this is what happens when we let the chair of the physics department I forgot what you were doing we're running a show and and also thank you for your time here so yeah, thank you for coming here everybody and I hope you have a safe journey home and thanks to our brave MCs for hosting the season and the four speakers will be available for questions on the Centennial Hall so thank you