And they talked about this new discovery, which is going to change the world of particle physics and how we understand the universe and I'm going.

And they talked about the how the electron is a perfect sphere.

And I'm thinking, Well, what experiment is this is, And gradually, as they talked a little bit more, I realized it's I knew what the experiment.

Waas and I even know the people who have done it.

There were my colleagues in Sussex, and so, uh, I know Johnny Hudson and Ed Heinz very well in Ben Sour.

And so it was really great to hear about the experiment.

I've never thought about it as being the electron is a sphere I've thought about Is the electron die pole moment somehow?

Don't think if that have talked about the electric dipole moment of the electron that might not have made the BBC news.

I can't give you the heavy experimental details because it's too complicated for a theorist like myself, But I can tell you some of the background, first of all, why?

Why?

I said the electron is a sphere.

When we we think of the electron actually as a fundamental particle, it's one of the building blocks of the standard model, and normally you think of that as a point like object.

So what does it mean to say it's a sphere?

Andi, I think what they're really talking about is the charge.

The electrons got a charge, an electric charge on day, talking about the distribution of that charge.

They've measured it to be almost spherical, and, in fact, to show the precision of their experiment, they've demonstrated that that distribution.

If if they could scale it up to the size of the solar system, then it would be a sphere to within a hair's breadth, they could measure a deviation of a hair's width.

So a sphere the size of the solar system they could measure deviation off that charge distribution of the hairs with it turns out that the that distribution of the charge around the electron is really important, understanding the nature of the matter.

Antimatter is symmetry.

The fact that we'll live in a universe made up mainly of matter, very little antimatter around, and yet we believe in the early universe.

They were created in equal amounts.

So what has happened on the By finding this a deviation of of this charge from this perfectly spherical charge, we would hopefully gain some information about this origin of this matter and to metro symmetry.

So let me step back before I go into those details and perhaps just talk a little bit about what it means to be not spherical.

So So it's vertical distribution of charge.

Basically, the way I think about it, anyway is that if you happen to have a detector that could pick up charge could measure charge than if, if my electron is here, then the detector would pick up an equal amount of charge on this side, as it would on this side, as it would up and down and all the way around.

It would perfectly spherical.

It wouldn't see any preferential distribution of charge that's called a mon, appalled by the way where it where it's equally distributed, like that spherical distribution.

Now the next thing you can do, you can if you want to distort.

This charge is the next simplest ones called a Di, polled on DDE, where used to die.

Paul's school were used to die.

Pole's magnetic die polls about magnet, right as a south Pole in the North Pole on We're used to that in magnetic cases, but he also exists in the electric case.

If I had a positive electric charge on a negative electric charge, then the dye pole would be and put them close to one another.

The die Paul would be a line that goes from the negative to the positive charge.

Right.

So this is the electrons only got a negative charge.

So it turns out that you don't have to have a positive and a negative charge to have a have a diaper.

You just need to have a distribution of the charge, which is not spherical.

So if, for example, I distorted this sphere, so I made it so that maybe more like a raindrop.

Okay, which has got a bull, a bull just end at one bit than a narrow end of the other.

So there's more charge over here and less charge over here.

Then I would have a diaper going from from 11 part to the other part.

That's what they're looking for.

That's what this experiment is looking for with the electron.

They're looking for this asymmetry in the charge and things that cause this.

A symmetry at the interaction of the electron with the other particles.

Now, in the standard model of particle physics, the one that describes the universe as well as we know it, the there is a near symmetry.

It's induced by the interaction between the electrons and the quarks, actually, but it's so small it's expected to be an observable.

So the fact that it hasn't been seen is no surprise.

But we know that the standard model of particle physics can't describe it, doesn't describe everything, so there are extra modifications could be on the standard model, which people have put forward.

There are lots of variants.

I'm one of the goals of places like the L H sees to test these models on what's wonderful.

One of the wonderful things about this experiment is a It's also testing these models, but be it's in a lab, much lower energies.

Just in the lab down Imperial College with the Head hangs and his group on.

What they're looking for, then, is the interaction between some of these new particles in particular supersymmetric particles.

They're called.

They're the partners of the particles that we that we know exist.

They're looking for the possible interaction between those particles and the electron Onda theories predict that in some of those cases, you expect them to induce.

This s a symmetry on what they've managed to demonstrate is through months and months.

In fact, years of working on this is that there is no asymmetry, even though they've got their sensitivity down, down and down and down.

The electrical distribution of the charge still seems perfectly spherical.

They're seeing no deviation.

That then means that those models which predict there should be a deviation that's already in excess of what has been seen a ruled out it doesn't rule out supersymmetry.

Supersymmetry is a vast subject, and there are lots of regions of parameters in supersymmetry, which you can still go to, which would be perfectly consistent with the observation of no distortion.

But it's severely constraining it what the experiment is.

So you've got to create this die pole you've got that you're trying to test for this die pole moment.

Well, resolutely put electrons in in an electric field.

But if you was to simply put an electron in an electric field.

You've created a little accelerator.

It's your cathode ray tube.

It's your television.

It shoots out and you've lost it.

So what they do is they put their look at molecules on dhe molecules of you.

Ter beom fluoride!

Okay.

Fluoride of Florian.

I've heard of incredibly reactive.

Apparently the U turbans.

Heavy, heavy, an atom of you turbines Very heavy.

We need Martin.

Anatomy of Florin is very light, so it itself already has room.

What I talked about the distribution of the the electrics produces the electric dipole moment in its own right.

And so the electrons are already enhanced by this being in the presence of this, these molecules.

So they put these molecules in than the apply an electric field that shifts the energy level of the electrons.

Then they switched the electric field, and the energy levels shift again.

Now, the amount of shifting of these of the energy of the electrons actually depends upon the dye pole moment.

So the bigger the shift of the electrons, the big of the dye pole moment.

So that's what they're looking for.

They're looking to measure this shift on bacon, double it up by reversing the field.

So that's goes from positive to negative, increases the range.

And that's what they've been looking for.

They've been They've been looking for that shift, and we've seen no evidence of that shift.

And in their analysis they have.

They look, they have all of these debt, all this data.

And of course, it's all done on the computer as well.

There's analyzing all in the computer, so there is a box there out of screen, which will constantly be giving them the electric dipole moment.

But they cover it up right.

They've had it covered up because they don't want to be influenced by the by the as they're trying to reduce all the errors, they don't want to sort of be influenced and have a quick look and said, Oh, if we just tweet that a bit more, we'll get this down.

Andi.

It's very important you do that that you it must have been so difficult for them not to go and have a quick peek to see what they were seeing on.

What they do is they eventually reached a stage where they think that They've basically accounted for everything they could possibly account for over that, you know, in a sensible time period.

And, uh, they pulled screener.

They pull the cover off the screen, and they look and I have.

So what happened yesterday?

I was on a panel with them, and I asked him what it was like.

You said they pulled it off.

We had a meeting.

That is that Is it time?

First time round.

There was disagreement.

People thought they could still work out a few more systematics.

And eventually the group said Yes, let's do it.

Pulled it off.

So the result it was their open a bottle of champagne and, uh, the world got to hear about it.