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  • Why is the Higgs Bos on?

  • It's what gives everything mess.

  • We weren't made of massive particles would fly around at the speed of light.

  • Some people would like that, but you'd never joined together to form bodies again.

  • So it's very important that we've got masses at first, like everything should go at the speed of light, and you've got to stop things going at the speed of light.

  • Otherwise, they're always ing apart, not interacting.

  • So you have to put a term in which allows for a mass, which will slow it down a bit.

  • But different particles have got different masses, you know, if you just think of the standard particles in the universe the electron, for example, and say the quarks, the top quark.

  • There's a difference of about a factor of 350,000 between the mass of the electron, the mass of the of the top quark, and yet those air in the same family of particles that make up the standard model and why it's ah, particle.

  • It's also what we call a field, which means it's sort of pay me eight all regions of space.

  • It's one of those things which is very esoteric off the end of the maths that most people couldn't deal with.

  • On off the end of the mass that most theoretical physics people can deal with, the particle is just the the end product, if you like.

  • The big thing you talk about that that particle physicists are interesting is the field.

  • The field is.

  • The is the concept of this object that permeates the whole universe.

  • If it's found, it gives a basis for cosmology and masses of particles so that we become Maur securing our ideas of what the universe is made off.

  • This is the difference between the field and the particle, the particles if you like other fluctuations, the oscillations in that background field.

  • So it's the equivalent of with electromagnetism.

  • We think of the electromagnetic field pervading the universe.

  • It's fluctuations of the photons, the photons of light, of the fluctuations in the field.

  • And that's what the equivalent of the bows on the particles are.

  • They're they're the fluctuations in this field, and then you, so you can imagine you need quite a lot of energy to get the field to get excited enough to produce those bosoms in the first place, and that's what the collision of the protons come do for you.

  • What happens when two protons collide?

  • Tremendous energies that makes the Higgs Bos on shorts face?

  • Well, I guess you know you just so that the way the Higgs has appeared and this is its do you create that they get this collision, you create particles, which then can annihilate, and you get a series of events happening now.

  • If you get enough of those, then rare stuff can happen.

  • Okay, what's one of the rare things happens that may have happened, we think, is that a Higgs particle decayed into two photons, and that's what we've detected, but in a way that only the Higgs would have done.

  • So that's how we've detected it.

  • Comic a suggestion.

  • Then why are we searching for the Higgs field while researching for the particles?

  • If they're so hard because they big field is even harder, that's the problem that so we're hoping that by finding the particles will actually gain some information about the field, I cannot explain it simply to the general public because it is well, I would use the word recondite on, and that's means that it's so obscure that you have to go and look up the words on the meaning in a dictionary on DDE.

  • That is the difficulty you have to use a mathematical language which is rather obscure in order to get to grips with it.

  • And you have to have a mental picture.

  • I mean, the one that's used, you'll find my colleagues love.

  • This is a Mexican hat.

  • Can I bring my heart into this part of this foot?

  • Well, this is where the Higgs lived that the Higgs lives on on this hat.

  • And you imagine there's a potential that runs down on, then has a minimum around here.

  • I think that is the stakes.

  • So you start out on its inn this point here, this this how is that?

  • Is what we call the Higgs potential.

  • It sort of controls while the Higgs doing so, you know, just think of the of the Higgs has been like a little ball on this hat, and it's rolling around at the top here.

  • Okay?

  • It's unstable because you know, the excitation stale because if you know a little bit, it's gonna fall down the heart.

  • Okay, Now that happens.

  • it rolls down, you get with process what we call spontaneous symmetry breaking, then the heads that Higgs ends up down here.

  • Okay.

  • And then the excitation Sze around that point here this point at the bottom of the hill If you like the bottom of the hat, those are what we call the Higgs particle.

  • Andi, it's some of the properties of the excitation Sze around this point also give mass to everything else That doesn't mean anything to you but to people in the field.

  • They would know roughly if whether I got it right for a start, I'm not sure I got it right on whether this is the right physics and it is the oscillation in A and a symmetric well, which has a certain symmetry which causes the exposer.

  • So the Higgs particle is a is a very unstable particle, and that's part of the issue, right?

  • If it was really stable, they'd be all out there, and you just got to find them.

  • So let me give you an idea of how difficult it is to generate them.

  • There are, on average, 200 million collisions of a second between the protons and the going one way and the other way.

  • So two protons smashed together and that's happening 200 million times a second, right?

  • This The accelerator's been running for about best part of a year.

  • 200 million collisions a second.

  • Do you know how many Higgs have been detected?

  • How many potentially have been detected in this?

  • This data in some of the channels?

  • Three.

  • Three eggs.

  • So these are small statistics, right?

  • Because they're very difficult to produce these particles and then and then be guaranteed that you be fairly confident that you've seen it because they there you need a lot of energy to produce them on.

  • Then they decayed very rapidly, and you have to be fairly confident that you understand the decay products in order to reconstruct.

  • What you think is that is the is the Higgs in the first place.

  • So there's there, many protons colliding and very relatively few Higgs being produced.

  • There's lots of other stuff being produced, which is far easier.

  • There was a conservative MP, William Waldegrave, who asked for people to write one page of a four to explain the Higgs Bos onto the public.

  • And there's a competition that somebody wanted and you can't really do that.

  • That's what you're asking me to do.

  • One page of a four written simply on talk about missing Satcher moving through a party and everybody coming towards own making a mass around Well, I could give you an analogy for how the how the Higgs mechanism works.

  • And so the mechanism the denouncing people normally uses is, they say, Well, imagine a room I don't know in Hollywood or something on the room's empty, and you get some superstar like Brad Pitt walks into that room and there's no one in the room, so you can walk about freely.

  • There's no problem.

  • Okay, now you go later on the day and the room is filled with people.

  • Okay, let's call them Higgs.

  • People have you, like, right now from pit walks into that room, and he can't so easily move about because everywhere he goes, he gets surrounded by these pigs.

  • People sort of wanna talk to you, want to be with him, you know, one associate themselves with it, and so if you like, it's difficult for him to move about.

  • It's like he's got sort of, you know, a lot of Mass, if you like.

  • That's the analogy of the Higgs mechanism.

  • Really, It's like, you know, you feel permeates space with with this particles Robin being here.

  • It's down here on then That gives mass that everything else that have sort of absorbs the mass from that that's not too tall.

  • You have to talk about broken gauge symmetry and different groups and all sorts of things which are too abstract for even undergraduates.

  • We don't teach them that it is a difficult subject for undergraduates.

  • You need it schooling in this subject before it makes any sense.

  • What happened last week?

  • What happened last date?

  • Well, I don't want to say that they discovered the Higgs Bos and because they didn't discover it.

  • But there was a smoking gun, Shall we say so?

  • Last week was the sort of the preliminary set of death that's that's really important, right, because there's a risk that everyone will say This is it.

  • Now it's all done.

  • This is a preliminary set of data, which is kind of the culmination off the initial runs that were done throughout this year.

  • Up until I think about Tober runs of the Alexeev Protons going around the galaxy and looking at the collisions on two groups, announced the results to of the experiments.

  • The atlas experiment in the CMS experiment on both was specifically looking for signatures of the Higgs particle on dhe.

  • They've both seen what looked like excess events.

  • That means events above what the background would be.

  • An above what you would naturally think you should get from the standard model.

  • And these events are Edison over.

  • Certain mass Rangers have said about 125 times the mass of the proton.

  • Andi.

  • What they're hoping is that as more and more data is tech and the significance of these events will it will either grow.

  • So they'll see more and more of these events building, building, building above the background, like a volcano rising up.

  • Or if these events are not really due to a Higgs what they'll see over the course of the next few months.

  • Is these events basically disappearing back into the background noise again?

  • I guess what would a beam or interesting is if they hadn't found it right, because then we'd be thinking, all right.

  • Okay, where did all this masculine?

  • So of course, It's the Higgs particle.

  • That's after Peter Higgs, the particle physicist in Adam Bro.

  • I got Higgs here, if I can find it.

  • This is 1964 Peter Higgs Broken Symmetries.

  • That's the paper where he comes up with a version which is written in the language of particle theories, which is Legrand Jin's and co variant derivatives and all sorts of frightening mathematics.

  • It when it's frightening for me because I'm not used to this language.

  • This work was done back in the 19 sixties, okay?

  • It actually I was thinking about this earlier today that it just shows, you know, you work on the topical things, you work on the exciting things.

  • In the 19 sixties, people were working on the standard model, and of course, they realize there was this problem with the masses of the gauge particles, and they knew they had to come up with a mechanism to give the gauge particles masses of Standard Model had the more massless So not surprisingly, it wasn't just Peter Higgs working on this.

  • There was, ah group brought in on glee.

  • We're working on it in Belgium.

  • And then there was a group of three people working on it in at Imperial College, including a good friend of mine, Tom Cable, and the paper.

  • They were working independently of each other on different aspects of it on DDE.

  • In fact, the papers all appeared within a few months of each other.

  • In fact, almost a few weeks of each other.

  • We will always be known as the Higgs mechanism in the community, and it would be outrageous if he's not rewarded.

  • But if the Higgs Bos on hasn't been discovered, no prizes will be awarded.

  • So it's contingent depends on whether they actually see it.

  • If they do see it, it's going to be somebody in that group.

  • Who'd you give the credit to it?

  • I remember at one stage when it used to be called the Higgs cable mechanism, and then it became the Higgs mechanism on dhe.

  • Who knows where I mean?

  • It looks cause it looks like it's got to go to Hicks if if a prize is given.

  • But there's this crazy ruled, I think, in the Nobel panel, which is it's meant to go to no more than three people.

  • Well, Brown sadly died earlier this year.

  • Historically, the order in terms of publications is brought in on glee, then Higgs and then cable in his collaborators on DSO you potentially got Higgs, and only and then you've got the three collaborators, so it's a difficult call.

  • I'm not gonna call it, but one of the three of them should get it.

  • I think they should abandon this three people maximum and give it to the whole five of them.

  • Yeah, there was such an exciting time.

  • Bread.

  • I mean, you know, you must be picking up on it, right in particle physics.

  • It's just great time, right with the neutrinos.

  • And then you've got this spherical electrons and you've got the l.

  • A.

  • C just producing this amazing data.

  • Yeah, we were all excited and then we it was all a bit of a damp squib for us because we went over to watch it all on a big screen.

  • We did watch on the Internet, and it was it was it was great, because the Internet connection is really not know Nottingham.

  • But it said so we had it all hooked up onto a big screen, you know, like, and the stream was just rubbish.

  • And it's kind of ironic because the guys its own invented the Internet, and yet that can actually wasn't working very well.

Why is the Higgs Bos on?

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希格斯玻色子--六十種符號 (Higgs Boson - Sixty Symbols)

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    林宜悉 發佈於 2021 年 01 月 14 日
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