 Welcome to Think Tech on OC-16, Hawaii's weekly newscast on things that matter to tech and to Hawaii. I'm Raya Salter, and I'm Elise Anderson. In our show this time, we'll cover the remarks of Professor Fred Harris, a high energy physicist at the meeting of the Science Cafe on April 18th. He called us Charm in China, but he was talking about the phenomenon of charm as it's known in physics, and that's a very different thing. The Science Cafe, part of the Hawaii Academy of Science, which presents the Hawaii Science Fair every year, meets monthly for informal discussions about science. The meetings are open to the public, and the talks are always interesting and popular. Professor Fred Harris is a scientist at the Department of Physics and Astronomy at UH Manoa. After taking a PhD in physics at the University of Michigan in 1970, he joined the high energy physics group at UH and has been teaching and doing research there for 47 years until his retirement this past February. The development of the Beijing Electron-Positron Collider began in the 1980s with advice from US physicists. This high energy physics project sparked the beginnings of modern science in China and has been of mutual scientific benefit. Led by Fred Harris, the university has been collaborating with its Chinese colleagues on this project since 1994, more than 30 years ago, using the collider's unique capabilities to study a wide range of phenomena in particle physics, including quarks and charms, hence the title of Fred's talk. So what is a quark? A quark is an elementary particle and a fundamental constituent of matter itself. Quarks combine to form particles called hadrons, including protons and neutrons, the components of atomic nuclei. What in the world then is a charm? Well, there are many kinds of quarks in particle physics and a charm quark is one of them. In fact, the charm quark is the third most massive of all the quarks. And yes, this will be on the final exam. Let me start by describing what the slide is. This is the entrance to the Institute for Energy Physics in Beijing. And this is where the Beijing Electron-Positron Collider is located and also the best experiment. This is a sculpture that was done by T. D. Lee. He's a Nobel Prize-winning physicist. He was located at Columbia. He's from China originally. And he's had a lot to do with the development of science in China, so I will say more about him a little bit later. Okay, so one of the things that I want to talk about is one of the highlights of the best experiment, and that's the fact that we think we have four quark matter. So this was the physics highlight of 2013. And this blurb down here says that quarks come in twos or threes. And the summer best three collaboration in China and the bell collaboration in Japan reported that they had found something mysterious particle that appeared to contain four quarks. And it was named ZC3900. So I hope to give enough background to say why this is useful, why it's important. This actually is in the University of Hawaii research journal. And again, it shows a picture of the best detector when it was being built. And again, it says that an international team says the discovery of electrically charged subatomic particle, the ZC4020, is a sign that they have a whole new family of four quark objects. So again, these are the highlights of the best experiment. This is the outline. It actually was up here for quite some time. So I'll give an introduction to what quarks are and particles with charm. Talk about the era where charmonium was discovered. And then the beginnings of the experiment in China and the connection with the US and Slack laboratory, Stanford Linear Accelerator Center. Come up to the present day experiment and then talk about the X, Y, Z states and bestos X, Y, Z and summarize in the end what the big science in China is now. So charm in China. So is this what I'm going to talk about charm in China, especially this guy here? Well, sorry, no. So again, we very often use words to mean something very different in physics. So by charm, I'm talking about quarks called charm quarks. And so one of the things we can ask is what are we made of? And obviously, boys are made of sugar and spice and all things nice and girls are snips and snails and puppy dog tails, right? A less poetic picture is that the world is made up of molecules, you and I, everything around us. Molecules are not terribly basic because they're composed of atoms. So for instance, the H2O molecule has two hydrogens and one oxygen. The oxygen atom is not really basic either. It has a very tight nucleus surrounded by a cloud of electrons. And the nucleus contains eight protons and eight neutrons. And the electrons are elementary particles, basic particles. But it turns out protons and neutrons are not because they're made up of things called quarks. So a proton is made up of two up quarks and a down quark. And these are held together by particles called gluons. So that brings us to the standard model of particles. And again, particle physicists like myself study all sorts of particles. And there's a whole book full of particles and their properties. And a lot of the properties have actually been measured by the Vest experiment. But these particles can be described in terms of these elementary particles. There are six quarks, the up, down, charm, strange, and top and bottom quarks. And those are what compose all of the particles in that booklet. There are also leptons. The electron is a lepton that you should be familiar with. That's basically what goes through the wires in your house to power all the devices that you have, electrical devices. There's a big brother of the electron called the muon. And then an even bigger brother called the tau lepton. So and then there are force carriers. The first one is the photon. This is the carrier of the electrical force. And then there's the gluon, which as I mentioned keeps the quarks together to form the proton. And then there's the Z and W boson, which are the carriers for the weak force. Excuse me. So visible matter like the proton is then made up of two up quarks and a down quark. A neutron is made up of one up quark and two down quarks. And the pi meson, which is a very common particle that is created in interactions or cosmic ray events, is made up of an up quark and an anti down quark. So the bar over the top means it's an antiparticle. So quarks have fractional charge, meaning fraction of the charge that the electron would have. They have mass, they have spin, they have color. And again, color doesn't mean red, white, blue like we normally think of color. This is a quantum property which the gluons couple to. So the u-quark is very light. The top quark is the heaviest of the quarks. And it's 180 times heavier than a proton. So it's very heavy. It can only be created in very high energy labs. So one of the simplest particles bound states that we can create with the strong force is called charmonium. I don't know if this is the best place to stand or not. And it's a charm quark and an anti charm cork. That's again the bar over the top. And you can form lots of different states with the C and the C bar. So the way we classify these states is with JPC. Quarks have spin, as I mentioned. And quarks can have, the charmonium can have a state where both the spins are up. So the total spin is going to be one. Or one spin can be up and one down. So the total spin is going to be zero. And this total spin then is decimated by S. They can also have angular momentum where the quarks are spinning around one another. This is called orbital angular momentum. That's designated by L. The total angular momentum is the sum of the two. So it would be J equals L plus S. And then there are a couple other quantum numbers, which I won't say too much about, called parity and c-parity. And so again, we have JPC here. And so we can have 0 minus minus, 1 minus minus, 1 plus minus, and so on, going across here. And this is the mass of those states. So again, this lowest state is about three times heavier than a proton. And we can get up to something like almost four times the mass of the proton. So these states have all been discovered, measured experimentally. And these are just the lowest mass states that you can form with a C-C bar state. There are many more up here, which I don't show on the slide. Potential models, which have been developed by theorists, can predict the masses of the undiscovered states. So the potential models use the measured masses of these lower states. And then they can use those with the potential model to predict the upper states. So again, Charmonium is a very simple bound state. What else can we do with Charm Quark? So we can combine a Charm Quark with a U-bar Quark, which is an anti-U Quark. And that forms something called a D meson. Or we can combine a Charm Quark with an anti-D Quark, and that becomes a D plus meson. Or an anti-strange Quark, and that becomes a D sub S meson. Again, zero plus being the charge of the particle. Can also form anti-particles of these, and we can form excited versions. We can also form Charmed Baryons. Remember that a proton, protons also called a baryon, had two up quarks and a down quark. So if we replace one of the up quarks with a Charm Quark, we make a new particle called the lambda C plus C again, means it's Charmed. And again, we can form anti-particles and many excited versions of these. So the thing to note here is that mesons are formed by a quark and an anti-quark. Baryons are formed by three quarks. And again, we can change one of these to a D or both of them to use and form other states. Okay, so I'd like to talk about the original era of discovery. So the Charm Quark actually was predicted. Glashau, Eliapus, and Miani proposed it as a way of solving the problem that the K long meson did not decay to a mu plus and a mu minus. Something that should be allowed by various quantum numbers and by the energy. In fact, I heard a talk by Glashau where he said that he was so convinced that the Charm Quark had to exist that if it did not get discovered, he would eat his hat. He had a big hat, so it was very impressive. Most theorists are not that brave. They don't predict that the particle will be discovered or they'll eat their hat. So this was in 1970, in 1974, Bert Richter at Slack, at Stanford announced the discovery of the Psi particle. And at the same time, Sam Ting at Brookhaven in New York announced the discovery of the J. They were the same particle. And so because they were both very impressive people, we ended up calling this particle the J Psi. That should be a Psi there. All other particles just have one symbol to label them. So this is Sam Ting at Brookhaven announcing the discovery of the J Psi. Again, the experiments back in those days had very few people. So that's basically the experimental group there. And I should mention that Sam Ting is also still active. He's head of the AMS experiment, which is the experiment that's flying in the space station. And it means the Alpha Magnetic Spectrometer. Sam actually came to Hawaii and met with Dan Inouye and the president of the university and convinced them that they should start an AMS group here at Hawaii. And I was able to create some faculty positions. So Veronica Bindi was here some years, some weeks ago, months ago. She was one of the AMS physicists whose position was created by Sam Ting. OK, so this was called the November Revolution because it was the discovery of the J Psi. And this J Psi had a mass of about three times that of the proton. And it was very soon interpreted as being made up of a Charm Quark and an Anti-Charm Quark. Because there were, again, lots of theoretical ideas that were put forth. But this was the one that survived. Sam Ting and Bert Richter received an award prize in 1976 for the discovery, again, because this was a very monumental discovery. And finally, I should mention that this led physicists to actually take quarks seriously. Before this, they were thought just to be a mathematical construct. But now that a fourth quark was predicted and actually found, people started taking the quarks as being physically real. So this is the discovery. This was an electron-positron collider. So the reaction here is actually E plus plus E minus goes to something. And so we have the electron and positron coming together head on. And when they meet, they actually annihilate. And they can create all of the energy that they have, can create a new particle. So what's happening here is that they're changing the energy of the beams at slack, increasing them slowly. And the event rate is very low down here. And then when they get to the threshold for producing the J-si particle, the event rate starts going up. So here it's 100 times higher than it is down here. So they didn't expect to see anything. And when they saw it, of course, it was a very exciting discovery. So this was the discovery, then, of the J-si, which is this particle right here, which is now colored yellow. So this is the first state discovered of the Charmonium states. Pardon? Were they both discovered in the same way? Well, I'll see you in just a moment. I'm glad you asked. So slack, of course, could continue raising the beam energy. So here they raised the beam energy up to about 3.68. And again, they saw this huge bump showing up, which is a new particle. And it turned out that was, in fact, the psi prime, which is the excited state of the J-si. And again, there are other psi states that can occur up here. So that was second. Now, slack is an electronic celebrate. Yeah. E plus E minus. Why are you using electrons rather than protons? Protons are not fundamental. So protons are made up of quarks. And so you're smashing a messy thing with a messy thing. And so the nice thing about electrons is that when you smash them together at this energy, all of their energy is being converted into the final state. OK. So anyway, this is the second of the general particles. Now, it turns out that these particles are not stable. They decay almost immediately. And so one of the things that they found, again, at slack was that the psi prime can emit a pi plus and a pi minus particle and then become a J-si state. And then the J-si state can decay into electrons. Again, neither of these are really stable. They decay into other states. And so this is what they actually saw in their detector. The electrons are rather high energy, so they come out in rather straight lines. The pions that are created are rather low energy, so they curve a lot here. So they saw something that they like to point out looks just like a psi. OK. So it proves that this is a psi, not a J. It's not a J. And so the other discoveries were 1974. This is 1975. So this is all happening very, very fast. Now, there are more states that can be produced. And here what happens is the psi prime emits a photon, a particle of light, and drops down to be a chi state. There are three of them, chi-c1, chi-c2, and chi-c0. And the energy of the photon then is really just the difference in the masses of these two states. These chi states can then again emit a photon and drop down to the J-ci state. And again, the energies will just be the energies of the difference. Or the psi can emit a photon and drop down to the eta. So if you plot the energy spectrum of the photons, it's smooth. Then you see these peaks. And these peaks now correspond to these photons that are being emitted. So here we are able to find the other states in the low mass region. OK, so that was the beginning of the Charmonium family being discovered. So I want to next talk about the beginnings of VEPC and BESS and how it was connected to Slack. So there was a very turbulent period at the beginning of the 20th century in China. The Communist People's Republic of China was formed in 1949. And then it became very closed until about 1972, when Richard Nixon went to China and met with Mao Zedong. And we're supposed to play the chairman dances here, but that doesn't work on the max, so sorry about that. Anyway, there's a nice little tune by John Adams, which describes the chairman coming down from a picture and dancing with his wife. OK, so that was the opening up of US China politically, but there was also a scientific opening up. And a bunch of this Chinese physicists visited major laboratories in the United States in 1972. Collaboration, especially including international collaboration, is at the heart of scientific discovery in the 21st century. It's obviously a mutual benefit for us to learn about our world together. Just as other countries learn from us, we learn from them, and science is thus advanced for all humankind. And science is so important for the University of Hawaii, which has so many excellent departments and researchers doing world-class scientific research, and for the state, offering great jobs, careers, lifetime learning, discovery, and recognition for our young people. For them to stay and do science here helps all of us. Scientific research attracts hundreds of millions of dollars in grants and is important to our economy, our future, and our relevance in a rapidly changing world. We are delighted that Fred gave this talk, that he covered this interesting and timely subject in high energy science, helping us understand the science and Hawaii's participation in its global diplomatic advancement, and that we had the opportunity to be there and film his talk and the discussion. The next meeting of the Science Cafe is on May 16th, and will feature researchers Chris Measures and Mariko Hata of the Oceanography Department at UH Manoa. They will discuss oceanography in the Arctic Ocean and the disappearing sea ice there. They'll talk about their expeditions to the North Pole and the physics and chemistry of trace elements and isotopes there, and how climate warming affects that special environment. We hope to cover that talk too. Check out high-sci.org. Given the disturbing changes being made by the Trump administration, especially the reduction of federal funding for scientific research, it becomes all the more important that we follow and speak out about what is going on in science. Many researchers at UH, along with many other people who support science, participated in the March for Science on University Avenue last week. ThinkTech was there, and we will be sharing our footage and our observations on that event on ThinkTech on OC16. So stay tuned for more about science on ThinkTech. And now, let's take a look at our ThinkTech calendar of events going forward. There's so much happening in Hawaii. Sometimes things happen under the radar, and we don't hear much about them. But ThinkTech will take you there. Remember, you can watch ThinkTech on OC16 several times every week to stay current on what's happening in government, industry, academia, and communities around the islands and the world. ThinkTech broadcasts daily talk shows live on the internet from 11 a.m. to 5 p.m. on weekdays. Then we broadcast our earlier shows all night long and on the weekends. If you missed a show, or if you want to replay or share our shows, they're all archived on demand on thinktecawaii.com and YouTube. The audio is on thinktecawaii.com slash radio. And we post all our shows as podcasts on iTunes. See our website for links. Visit thinktecawaii.com for our weekly calendar and live stream and YouTube links, or sign up on our email list and get the daily docket of our upcoming shows. ThinkTech has a high-tech, green screen, first amendment studio at Pioneer Plaza. If you want to join our live audience or participate in our shows, write to think at thinktecawaii.com. Give us a thumbs up on YouTube, or send us a tweet at thinktech.hi. We'd like to know how you feel about the issues and events that affect our lives together in these islands. We want to stay in touch with you, and we'd like you to stay in touch with us. Let's think together. You can call in to our talk shows live. While you're watching any of our shows, you can call in to 415-871-2474 and pose a question or make a comment. We'll be right back to wrap up this week's edition of ThinkTech. But first, we want to thank our underwriters. That wraps up this week's edition of ThinkTech. Remember, you can watch ThinkTech on OC16 several times every week. Can't get enough of it, just like Elise does. For additional times, check out oc16.tv. For lots more ThinkTech videos and for underwriting and sponsorship opportunities on ThinkTech, visit thinktechawaii.com. Be a guest or a host, a producer, or an intern, and help us reach and have an impact on Hawaii. Thanks for being part of our ThinkTech family and for supporting our open discussion of tech energy, diversification, and global awareness in Hawaii. You can watch this show throughout the week and tune in next Sunday evening for our next important weekly episode. I'm Raya Salter. And I'm Elise Anderson. Aloha, everyone.