JOE PALCA, host:
From NPR News, this is TALK OF THE NATION: SCIENCE FRIDAY. I'm Joe Palca.
A lot of what we know about the inner workings of matter comes from particle accelerators. Sure atoms are made up of protons, electrons, and neurons, but those particles are made up of even more basic particles themselves, things with names like quarks, bosons, gluons, and more.
To see these, you have to break them out of their larger hosts, usually by slamming the larger particles into each other at very high energies to make them break into pieces, then hoping to take a picture of those tiny pieces before they disappear, and they disappear very quickly.
Later this year, a new particle accelerator is scheduled to start operation at CERN in Switzerland. Called the Large Hadron Collider, or LHC, it will fire beams of protons into each other with very large amounts of energy. Scientists hope that these high-energy collisions will be enough to kick free particles they've never seen before, including one which has been sought after with great intensity called the Higgs boson.
Joining me now are my three guests for the rest of the hour. David Barney is the outreach coordinator for the Compact Muon Solenoid. That's one of four detectors - detector experiments at the LHC collider part of CERN in Geneva, Switzerland. He joins me by phone from France. Welcome to the program, Dr. Barney.
Dr. DAVID BARNEY (Outreach Coordinator, Compact Muon Solenoid): Hi, nice to be there, virtually at least.
PALCA: Well, it's good to have you. Jacobo Konigsberg is a professor at the Department of Physics at the University of Florida and is a spokesman for The Collider Detector at Fermilab in Batavia, Illinois. Welcome to the program.
Dr. JACOBO KONIGSBERG (Spokesman, The Collider Detector at Fermilab): Thank you. Good to be here.
PALCA: And I think I mispronounced. It should be Jacobo, right?
Dr. KONIGSBERG: No, Jacobo is correct.
PALCA: Jacobo, OK, very good. And Barry Barish is the director of the Global Design Effort for the International Linear Collider Project. That's another new collider still in the planning stages. He's also an emeritus professor of high energy physics at Cal Tech. He joins me from the studios of member station KPCC in Pasadena. Welcome back to the program, Dr. Barish.
Dr. BARRY BARISH (Director, Global Design Effort, International Linear Collider Project): Hi, I'm happy to be here.
PALCA: Great. And as always, if you want to join the conversation, please give us a call. Our number is 800-989-8255. That's 800-989-TALK. And I guess, Dave Barney, we should start with you and get a little bit of a description of LHC, this new collider that's coming to completion later this year.
Dr. BARNEY: Hi, yeah, I mean I'm working for, as you said, one of the experiments that's being based at the LHC. And the LHC is going to be the highest energy machine of its type ever made. It's housed inside a ring about 27 kilometers or about 15 miles in circumference, about 100 meters or 100 yards underneath the border between Switzerland and France, near Geneva. So this accelerator we've actually been working on for the best part of the past 15 years, from concepts to design to actual construction, and now we're in the phase of - we'll be starting the commissioning of the machine later in this year.
And this essentially circular device makes protons travel near to the speed of light in both directions around this ring, and these protons collide with each other at four specific points around the ring. And where they collide is where we build our detectors, or our experiments, to try and see what actually happened during those collisions. So as I said, I work for one of those four detectors, called CMS, which somewhat cryptically stands for Compact Muon Solenoid. But don't let the name Compact fool you here. I mean Compact means we've tried to squeeze as much as possible into a fairly small space, but in fact that space is about 23 yards long and about 15 or 16 yards high.
Dr. BARNEY: And it's a device that weighs about 12 and a half thousand tons, so Compact doesn't necessarily mean small.
PALCA: Got it. So these are detectors - these particles that come off, they don't come off with little nametags on them. So what are you trying to detect? How do you know what you're seeing?
Dr. BARNEY: Essentially what we've tried to do is we design our detector to look for the particles that we know and love, in fact things such as you mentioned earlier, like the electron or the neutron or the proton, or similar things a bit more exotic, such as pions. And these particles are what we call the stables ones. We know how they behave, and they live for a relatively long time. So that once they come out of the collision, they travel through the detector and leave telltale signatures inside. So they'll leave different sort of signals in the different layers of our detector.
And you can imagine our detector looks somewhat like an onion, albeit a cylindrical onion. But it has different layers that do different jobs and see the different particles in different ways. So we look for these signatures of these particles that we know. And what happens is if we create something in our proton-proton collision that's interesting, let's say, such as this Higgs particle that may or may not be there, then we know from the theory of this particle what it might decay into. And the Higgs particle will only live for a very short time before it decays into something else, into these well-known particles eventually. So what we look for is these well-known things and trace back, a bit like a detective at the scene of a crime, looking back to see what actually happened in the first place.
PALCA: Got it. Well, let me turn to you, Jacobo Konigsberg, and ask - I mean what has the LHC, this new machine, got that you guys at Fermilab don't have?
Dr. KONIGSBERG: That's a good question. I would turn it around. What do we have at the moment that they don't have? And which is data. And we are running - we're running an experiment that has been gathering data for about five, six years now. And we are very engaged in analyzing this data, the way that Dave very eloquently described, trying to understand what are the particles that we are producing them.
We have a lot of experience with this machine because this accelerator Tevatron at Fermilab started operating in earnest perhaps 20 years ago. And this machine has been upgraded every so often to really achieve high - ever higher collision rates. This machine now is operating at its peak, and we actually have a good opportunity to see and search for many things that we don't know. We really at the moment, and hopefully for two or three more years, while the LHC machine turns on - the turn on of that machine is going to be slow, but it's coming - and through that time, we expect to continue the wonderful studies. We have an incredible collaboration of about 700 physicists from 60 institutions and on universities across the world - very committed, very curious and passionate people. And we are - you introduced the segment as the new toys for high energy physics...
(Soundbite of laughter)
Dr. KONIGSBERG: ...so at the moment are playing in the sandbox. We are the ones playing. We're having a lot of fund. We invested a lot of time here. And we actually have maybe a good or maybe not such a good shot at finding the Higgs. We can also think of the impact that not finding it, or that excluding certain regions where the Higgs mass(ph) maybe will have in the LHC experiment. So in a way we are also training students, we're providing a lot of people transitioning to the LHC with lots of experience, and we are a community. I don't think we should see these two efforts as entirely competitive. This is really a transition that the field of high energy physics is going through.
PALCA: A community that likes to compete, though, I think...
Dr. KONIGSBERG: Absolutely.
PALCA: Or at least at some level. OK, well, then maybe I can turn to you, Barry Barish, and ask if, you know, what - if Fermilab is providing some interesting data and LHC will provide some interesting data, what is the International Linear Collider going to provide that these guys won't?
(Soundbite of laughter)
Dr. BARISH: Well, first, we represent the dream or the future, or what we think might be the future, of the field. And the more they find, the more interesting that is actually. We're talking in our community worldwide, about maybe what you'd call a companion machine for the large Hadron Collider that has the history of several decades of the way we've studied particle physics, and that is to have also the complementarity(ph) of the collision of electrons and positrons, not protons - which are very complex objects - in the same energy regime. So we're trying to develop the technology, the design of a machine that covers the same energy range as the LHC but collides electrons and positrons. And because they're so much more elementary in electron and positron we're able to study this science in a very different way - or a complementary way.
PALCA: All right. So we have these three instruments. And we're going to learn a lot about physics. And maybe we can ask our callers if they have any questions about that.
So let's start now with Bill in Jackson, Wyoming. Bill, welcome to the program.
BILL (Caller): Hi. Thanks for taking my call.
BILL: I just wanted to ask with the energy crisis (unintelligible)…
PALCA: Okay. Bill, are you…
BILL: …over immediate application like wind power and solar power. I was wondering what the guests think the practical applications of the results of this (unintelligible) might be.
PALCA: Ah, the practical applications questions. That's a tough one. But maybe Barry Barish, do you want to take a swing at that?
Dr. BARISH: Sure. First let me say I'm not going to avoid the question. It's a shame that it's the first question, because we're more about science than about applications. But let me…let me say how we kind of have a different environment than what we lived in the beginning.
Physics basic research studies fundamental things. And often we don't know how they'll pay off. In recent generations we've had, for example, in physics laboratories nuclear magnetic resonance.
That ended up being the physics experiments - we didn't know it at the time - that have developed MRIs that we use to understand the insides of our bodies, medically. The development of lasers - lasers were only developed several decades ago as a basic physics principle. And they're now used in our CD machines and everything else that we have.
Dr. BARISH: More recently - even in one of the labs being talked about here - at CERN they developed the Worldwide Web which we all are finding indispensable tool even though at the time it was developed, a little more than a decade ago, it was just to communicate between two physics labs.
And, you know, more other daily applications we use physics principles, like general relativity, to - and couldn't do what a GPS does, to tell us where things are, without using general relativity.
So as we master physics we're able to find many, many applications. The kind of thing that we're doing here doesn't have direct applications except through the technologies. A lot of the technologies we are developing directly push the state of the art. And we're able to do that because we build one-of-a-kind things to do science research while industry has to worry about a bottom line.
So we develop abilities to have advanced electronics control systems, ability to handle seismic vibrations, and so forth, in our laboratories and then they get applied.
So we don't immediately solve the energy problem, or we don't know what problem we solve, but we master physics. And that helps us master kind of the environment around us.
PALCA: OK. Well that - that sounds like a…
Dr. Konigsberg: We also may be training people who will solve the energy problem.
PALCA: Exactly. Exactly. So…
Dr. Konigsberg: That's another aspect of this science.
PALCA: …all right. Well we're talking about the new - the new tools and toys, I guess, of high energy physics. I'm Joe Palca. And this is TALK OF THE NATION from NPR News.
Let's see if we can get a more sciency(ph) question now from Michael, Michael in Kalamazoo, Michigan. Welcome to the program.
MICHAEL (Caller): Hi. Thanks for having me on.
MICHAEL: I just wondered, you guys talked on the Higgs boson particle, I believe it is, earlier. And I'm not much of - I know a little bit about physics. Not much. But I'm just wondering if you could explain that a little more and what it means if it actually does exist.
PALCA: Oh good. Well let's - let's throw this one to Dave, Dave Barney. I'm sure the French - at least sitting in France - must give you a good perspective on that question.
Dr. BARNEY: Yeah. I would say right now I'm not actually French. I'm English.
PALCA: Oh really.
Dr. BARNEY: Just been living here for the past nearly 15 years now and working here.
Dr. BARNEY: The Higgs particle - well let me go back a step. I mean we have some fairly fundamental, simple questions about the universe that like a 10-year-old child wouldn't be afraid of asking, that most adults just think all that's taken for granted. And they don't even think about asking it.
Like, for example, as Joe mentioned right at the beginning, we have different particles, such as protons, neutrons, electrons, that we know about. But there are very simple things we don't know about these particles, such as why one type is heavier than another.
Now it sounds like a philosophical question, if you like. You know, do we really care about this? Well, in fact we do because the mass of the particles governs the way our world is. If the electron were heavier than it is then people would be much smaller than they currently are. And the whole world would be a completely different environment.
So it's a very interesting question to us, and a very basic thing. Now the best theory that we have at the moment or perhaps the best theory is that there's another part of particle that we haven't yet discovered that was postulated by a Scottish theorist called Peter Higgs plus a couple of other people, that was termed the Higgs boson.
Now this particle is supposed to essentially give all the other particles mass. And it interacts with different particles, more strongly or more weakly, dependent on what that particle is.
So it might give some particle some mass. It might not give others anything. It might give some a lot more.
So we believe - or our best guess at the moment, is that this particle is there somewhere. And what we need to do is try to find it. The biggest problem is that so far we haven't yet found them.
So despite the best attempts on both sides of the Atlantic, and in Japan, and in other places around the world such as Germany, we haven't yet found this thing.
Now what we believe is that the LHC is probably the best chances of finding this although it was said earlier that the Fermilab experiments might also do this. But the difficulty is that the chances of finding something, or the chances of creating this illusive particle where we know from our theory about it that it's very remote, it's very difficult thing to create.
So what we have to do is we have to collide particles together, protons together, extremely often. And on - in the hope that one in a million or one in a billion times you actually create one of these Higgs particles and you manage to see it with your detector.
PALCA: Well we're going to have…
Dr. BARNEY: (unintelligible) trying to do at the moment…
PALCA: Right. Try…
Dr. BARNEY: …trying to get as many collisions as possible…
PALCA: We're going to have to take - I'm sorry. I don't mean to interrupt. But we have to take a short break. And we'll try to sort this out when we come back. So don't go away. We'll be back.
This is TALK OF THE NATION from NPR News.
(Soundbite of music)
PALCA: From NPR News, this is TALK OF THE NATION: SCIENCE FRIDAY. I'm Joe Palca. This program note, coming on Monday a couple of very unlikely friends. While writing his latest book, veteran war reporter Thomas Ricks created a soundtrack to work by including the music of an up and coming young folk rocker. And on Monday Tom Ricks joins Neal Conan for a live performance by his friend, Josh Ritter. That's Monday on TALK OF THE NATION.
This hour we're talking about high energy physics. My guests are David Barney from CERN in Geneva, Switzerland, Jacobo Konigsberg from Fermilab in Batavia, Illinois, and Barry Barish, he's the director of the global design effort for the International Linear Collider Project.
And David Barney, I think you were just finishing up the description that the Higgs boson is going to be hard to find. And is there anything else that you briefly wanted to add to that?
Dr. BARNEY: No, no, no. That's the end of my description about that.
PALCA: All right. Well I thought it was actually - I thought it was quite excellent. Let's take - let's take some more calls now. And let's go to Roland in St. Louis, Missouri. Roland, welcome to the program.
ROLAND (Caller): Thank you for accepting my question.
ROLAND: It's more of an engineering question. Exactly how does your detector work?
PALCA: Ah. Ah. Well I'm sure we get three answers if we ask that to three people. But I'll start maybe with you, Jacobo Konigsberg. How does your detector work?
ROLAND: I'll take my question off the air.
PALCA: OK. Thanks.
Dr. Konigsberg: Right. Well it's a complicated answer because each of these detectors, as Dave described, is really made of a tremendous amount of components that they all need to act together.
So you need to think of each of these big detectors as a 3-D puzzle. Each of the pieces has to look at these collisions simultaneously with the other ones. And as these particles come out of the collision traverse each of these pieces, they need to immediately digitize, let's say, the passage of these particles through these detectors.
And then we need to build very sophisticated electronics to very quickly understand whether this particle collision - we call them events - were interested or interesting enough to pass it on to another level of sorting before we decide to write these events to a medium where we can analyze them further.
So it is like a camera that has to operate at a very, very fast rate. But taking pictures of detectors that are built of very thin wires embedded in gas with very high voltage in them that I - particles, charged particles, have passed through this gas, ionize the gas, and then the signals get recorded by the wires, or sandwiches of plastic and iron or lead that really capture the particles passing through them and convert their energy into a measurable quantity.
I think we can go on and on…
PALCA: Yes. I understand. But…
Dr. Konigsberg: …on this but I hope this is…
PALCA: …no that was - that was very interesting. And actually before I let you go - because I want to ask Barry Barish something. But before I let you go you've been collecting data for quite a while now. Is it possible that the data that has the proof of the Higgs boson has already been collected and it's buried somewhere yet to be analyzed?
Dr. Konigsberg: Most definitely. The problem with that is that it's not enough to have a few of those events collected among the millions, or really billions, of other events that we've collected.
What we need to do is collect enough of these Higgs events so that we can really look very, very carefully at everything and convince ourselves that we have some events that really are Higgs.
And this is a very, very tricky business. We have experience with a top quark(ph) that we discovered in Fermilab in 1995 where we were producing top and anti-top pairs every 10 billion collisions.
Dr. Konigsberg: OK? And we collected data for about two years. And we very carefully and very slowly analyzed it until we were able to convince ourselves and others that there was no other choice but to have a new process that has - hadn't been seen before that was very consistent with production of top corks.
We're trying to do the same with Higgs. The only problem is that Higgs, at the Tevatron, is even more rare than the top quarks. Instead of every 10 billion collisions producing at top quark we may have every 100 billion collisions producing a Higgs, if it's light enough, or every one trillion collisions producing the Higgs.
PALCA: Got it.
Dr. Konigsberg: Now given time we can collect enough data to do this work.
PALCA: Got it. Well, and as I gather time is coming - is coming to a close. But maybe - maybe I can turn to you, Barry Barish. I mean as I listen to these descriptions, first of the Higgs boson and what I would call a heroic description of by Jacobo Konigsberg to explain how a detector works, is this a problem for the field of high energy physics that it is a little bit esoteric and hard for the general public, even the scientifically interested general public, to appreciate the importance of?
Mr. BARISH: Oh, I think definitely. You know, we look at problems that seem very esoteric, the names of the particles we talk about, the particular questions we ask, but I think it was pointed out that - earlier in this program - that many of the questions that we're asking now could be almost understood, at least as questions, by a 10-year-old.
And I think that's true, and it's been a change of the nature of the field. When we did particle physics two or three decades ago, we basically built a new accelerator and knew we'd find and make new discoveries, and all we did was move into a new let's say window on that universe.
Today we actually are designing the accelerators and the particle detectors much more to answer specific questions. We've been talking about one, which is the Higgs Boson, but the underlying question there is what is mass all about? We know that our planet, ourselves, are made out of - we have mass. Where does it comes from and how do we understand it?
We have a lot of other questions like that that are guiding us. We think we live in what we call a four-dimensional world. We all know that we can go forward and backwards, up and down, sideways, and time is different today than yesterday, and those are our four dimensions.
But modern theory indicates that there may be other dimensions that we haven't seen yet, and it's really because they're smaller than we can see with in our everyday life. And so we're asking fundamental questions like how many dimensions there are in nature and what causes mass?
Those are very, very basic. You'd think we could explain it to everybody, but it certainly doesn't affect everyday life every much. So it is, I think, a real problem for us to communicate the importance of the questions we are asking, our ability to answer those, the direction we have to the general public.
PALCA: We're talking about high energy physics and some of the experiments that are being done in that world. I'm Joe Palca, and this is TALK OF THE NATION from NPR News.
And I've said that at the wrong time, haven't I? Yes, of course. Anyway, let's take another call now, and this time let's go to - I'm sorry, Brian in Muskegon, Michigan.
BRIAN (Caller): Hi, thanks for taking my call.
PALCA: You're welcome.
BRIAN: I was wondering that if while you're doing your experiments, if you were to get something that you totally didn't expect, how would you be able to discern that, and I mean would you even be able to make sense of out anything like that?
PALCA: Interesting question. Maybe Barry Barish, you want to take a quick swing at that?
Mr. BARISH: Yeah, actually I just talked about the fact that we're very directed now, compared to decades ago, but still the serendipitous discovery has always been maybe the most exciting thing in science, that we see things we don't expect.
When we design these experiments, these complicated experiments like we heard just explained, we actually use our imagination as much as possible to cover the bases, if you want, to try to make a design that doesn't just answer the directed questions that we're aiming for, like how we can see the particular decay modes of this Higgs particle, but might see other things.
And we always have adventurous experimenters that look at the data exactly for those reasons. They look to find the particular events that look funny and see if they look funny because the instrument behaved funny or maybe there's a new phenomenon that we haven't seen before.
And actually, the advances in this field and in other fields are some combination of directed research and kind of the surprising discovery, and it's part of what makes it exciting to be a scientist.
PALCA: All right. Let's take one more call now from Piers(ph) in St. Paul, Minnesota. Welcome to the program.
PIERS (Caller): Yes, sir. I'm honored to be part of this. I wish you'd talk a little bit about the consequences of not finding the Higgs Boson. Suppose after another 10 years of operation of the LHC, and you know you're doing everything right, and you don't find it, then what?
PALCA: Okay, that's a good question. Dave Barney, will you give the money back?
Mr. DAVID BARNEY (Outreach Coordinator, Compact Muon Solenoid, CERN): No, we'll take it and run.
PALCA: I see.
(Soundbite of laughter)
Dr. BARNEY: Essentially it is a good question. One of the - and it sort of stems also from what Barry was saying about the unknown, and indeed with the detectors being built at the LHC and the LHC itself, we don't really know what we're going to find, if anything at all.
Now what we do know from the current theories that we have that work extremely well and the bits that go on the end, like this Higgs Boson theory and so on -what we know is that if that particle exists, then the LHC has the energy and it has the collision rate to discover this thing within a few years of operation.
There are two really big experiments being built - CMS, that I'm working for, and another one called ATLAS - that are what we call general-purpose detectors. They're being designed to try to see whatever might be there. If the Higgs is there or something like it, something that could explain mass that fits in our current theories, it will be found at the LHC. There's no doubt about that.
The problem comes in that if we don't see it at all in several years of running, it means it really isn't there, and in fact our theories are wrong in some way. Now, this might sound like a get-out clause, if you like, but in fact to a lot of people that would be even more interesting.
And for the last 10, 15 years, we were running experiments such as the ones at Fermilab and other ones at CERN that were taking very precise data about our current understanding of the universe, a thing called the standard model that describes the particles that we all know and love, and it worked extremely well, with amazing precision, probably the most accurate experiments ever done.
And we know that this is our theory at the moment, but maybe we've got it completely wrong, and we're just seeing an approximation of something else that might be there. Perhaps there are more dimensions of space, as Barry was saying, and maybe this is hiding something much more fundamental from us.
I think it will be very interesting if we don't find Higgs.
PALCA: We are talking about high energy physics, and I'm Joe Palca, and this is TALK OF THE NATION from NPR News.
Well, maybe I can ask you, Jacobo Konigsberg, would you be satisfied that the lack of evidence is the proof that there's something lacking?
Dr. KONIGSBERG: You mean at the LHC or -
PALCA: Right, yes. I mean, do you agree with -
Dr. KONIGSBERG: I think I agree with that. It will be very interesting to understand that the standard model finally does not hold together the way we think, and that there is conclusive evidence from our accelerators that there should be something different and that we need to revise the understanding we have.
What Barry said is quite correct. One of the things that make this whole enterprise really exciting is searching for the unknown, and we have these theoretical guidelines that more or less predict or suggest what good solutions are for the various problems we find, such as the mass hierarchies (unintelligible), the problem that we don't really know the source of why different particles have different masses.
And understanding that is fundamental, and why it's fundamental because historically it's been so. When we set out to understand the periodic table of elements, we learned a whole lot about the universe. We understood the atom, and quantum mechanics came out of that. Every time we see patterns in the universe, and humankind has been pursuing these questions, mostly very, very interesting things happen.
So it's a fantastic enterprise, and we really are very excited to be part of it, and great nations do great enterprises. So we're very hopeful that we continue on this path, and I'm sure Barry shares that.
PALCA: Let's go to Jim now, Jim in Paltney(ph), New York. Jim, welcome to SCIENCE FRIDAY.
JIM (Caller): Hi. Thanks for talking my call and especially thank you for discussing real, cutting edge physics and real science, and my question is, given that the Large Hadron Collider could create conditions which would generate a small black hole, would you explain to us how you decide the size of a black hole? Is it mass or is it volume?
PALCA: Maybe I could ask Barry Barish to take a swing at that. Is that possible?
Mr. BARISH: Sure. These kind of questions sometimes don't really have very sharp answers. We know we can create something like a small black hole, but remember, a black hole is a very complicated object that has to do with space-time.
One of our biggest questions in physics is somehow reconciling space-time, if you want, or general relativity, with particle physics. So when we get into a realm of asking a question like the one you asked, it gets to some of the deepest questions we have. How do we bring together a very successful theory, quantum mechanics, with another very successful theory, general relativity?
And we have ideas how to do that, and those ideas can end up creating things on particle accelerators that come out of both theories, but I would say we're on very shaky grounds writing it down theoretically.
If that's so, then it becomes more like the kinds of searches that we were kind of talking about before; that is, that we see something - we don't know exactly how to search then, so we basically see something in the data that we're not expecting, and then we try to interpret it.
PALCA: Well, you know, this is the kind of program that concerns me a little bit because it gets to the point where it's so interesting that you figure you could go on talking about it for hours and hours. But alas, I think we've come to that point where I have to say goodbye.
So I would like to thank my guests this hour. David Barney is the outreach coordinator for the Compact Muon Solenoid, the CMS. That's one of the four detector experiments at the LHC. That's part of CERN in Geneva, Switzerland. Thank you very much.
Dr. BARNEY: Yeah, thank you very much. It's been an enjoyable half an hour.
PALCA: And Jacobo Konigsberg is a professor in the department of physics at the University of Florida and is the spokesman for the Collider Detector at Fermilab in Batavia, Illinois. Thank you.
Dr. KONIGSBERG: Thank you very much.
PALCA: And finally, Barry Barish is the director of the global design effort for the International Linear Collider Project. That's another new collider, still in the planning stages. He's also an emeritus professor of high energy physics at Cal Tech.
Mr. BARISH: Thank you for having us.
PALCA: You're welcome. Thanks to all of you.
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