Don't have any. OK, thank you.
Everyone can hear me. Sounds like I can hear myself, which is a good start.
OK, so yes, as you've just heard, I'm going to be breaking down a little bit more in a little bit more detail.
If you like how we know what we're doing, see how we can use those protons to tell us about the Higgs and all the other exciting things we're doing.
So indeed, we've heard we've heard from Gavin about the Large Hadron Collider at about.
You know what it can do, what the physics it can probe, and we know we saw in that animation, what's it doing?
Well, it's it's getting protons, it's accelerating them to high energies, essentially smashing them together and seeing what happens.
So, you know, there's a lot in that kind of sentence, I suppose, you know,
how do you go from smashing something together to seeing what happens to understanding things about the Higgs boson?
And it's, you know, it's it's not a trivial thing, and it's there's a lot of interesting physics in that.
So we're colliding protons, but we know protons themselves a composite complex, objects made of quarks.
And so the question is, what is a proton? I told you half the answer, but there's more to it than that.
And crucially, actually, how does it behave when we give it the LHC treatment and really speed these things up and we collide them head on?
So that's what I'll talk about first from a fairly briefly from a historical point of view, kind of telling you what the proton is.
I'm sure you'll know some of it, but probably not all of it. And then going going on to here.
So here is the roadmap. And it's worth remembering that over the past century, we really have come a long way in understanding,
well, festival, all discovering a proton and then actually understanding what it is.
And it's really a story that's continuing today.
Well, basically uncovering layers and layers of deeper complexity and substructure, complexity and simplicity,
if you like, but certainly substructure things going on at smaller and smaller, distant scales.
So we start with Rutherford's on the discovery of what the nucleus?
And then we know that that is then made of protons, and then we find out what actually, the proton is not a fundamental object.
It's made of corks, and these things interact via quantum chromate dynamics and building on all of that understanding.
Here we are today, and we're really using these things.
This complex mass, if you like here as a precision discovery tool and a precision tool to actually probe the Higgs boson.
So, yeah, how do we do that? Well, let's start at the beginning.
And remember, you know, start the 20th century, we didn't really know what an atom was, let alone a proton.
You know, atomic theory was well established, but we didn't really know what this thing was. We knew there were things called electrons.
We knew there was some rough kind of size 10 to the minus 10 metres.
We knew that they were neutral and therefore that had to be something with positive electric charge.
But potentially it could just be some typical plum pudding like picture a big cloud of positive charge with the electrons dotted in amongst it.
How do we go further than that? What we need to look to look inside the atom?
Not in order, not, you know. How do you look inside something that's that small is not obvious.
And the answer is, well, rather like, you know, I look at our desk photons from the beam photons coming from the Sun.
If you like from the lights, they scatter off the desk, they go into the detector, which is my eye.
And I see that as a desk that is not so different from that, just a very much higher energies.
So Rutherford's, he collided, positively charged alpha particles, helium nuclei with a gold foil.
And he looked at what happens. And that's the basic idea basically on a tabletop in a basement 100 years ago.
So it's basically the fundamentally the same thing we're doing today, colliding things with seeing how they scatter.
We're seeing how to interact. We're seeing what that tells us.
So, of course, he found out that these alpha particles tended to scatter sometimes at rather large angles,
and that was something you couldn't understand from having a diffuse cloud. Rather, that had to be a compact nucleus with a positive charge.
So the alpha particle came in and got to flight and got deflected off.
And you know, it wasn't just a statement of that sort, it was a quantitative statement.
You can predict here, you know, there will be a few equations, but not too many, I promise.
But you can predict how many alpha particles are scattered.
Some give an angle just from the kind of cool on repulsion from that nucleus.
And indeed, it exactly matched that formula, so a point like nucleus with positive charge.
So in what sense was it point like, I mean, how can you ever say anything's point like?
Well, you know, we can never really say is at its point, like within the resolution of the experiment.
So it's smaller than whatever distance scale you can probe.
Distance scale here rather straightforwardly was essentially how close the alpha particle could get to whatever this thing was.
This nucleus was under the Coulomb repulsion that was about 30 metres very small compared to
the atom radius somewhat larger than it turns out Inupiat to be the one the proton size to be,
which is about one centimetre, as I'll discuss. It's a little bit more about that, just breaking it down a little bit more.
If we want to go further, we know Proton exists, we know it's rather small.
But is it point like, does it have an extent? What's it made of?
And the idea is to look deeper and deeper inside the proton to get to higher and higher energy particles and electrons, for example of this thing.
And again, just to see what happens.
And the basic idea is, if you imagine an electron scattering off the proton blob here, it will interact by photon exchange, as we've heard.
And that photon will have a characteristic wavelength.
Losing I and using your kind of classic plank formula relating the energy of that photon to its frequency,
you can get the wavelength of that photon, which gives you the resolution scale in terms of its energy.
And the crucial point here is that the higher energy, the smaller the resolution.
And so we can plug in some rough numbers if we want to plug, if we want to probe a distance scale of one centimetre, that's 10 to the minus 50 metres.
That is, as it turns out, about the size of the proton. You need an energy for that electron of about one GV.
Remember, now this is this energy unit, if you compare to the energies of the protons,
the LHC, the seven thousand, these doesn't seem like much, but in the fifties.
Yeah, I can assure you it was quite the kind of technology then to get to that energy.
And so we build up, we collide Hofstetter, he collides an electron beam with about half a G.V. with protons.
We only have the technology ready status in the fifties. And you see what happens again.
So we have this rather old looking plot, but you know, there's a lot of very interesting physics hidden within it.
So we have the number of scattered electrons again against the scattering angle.
And what you have is a prediction here, which is just that Rutherford prediction,
what would happen if the Proton continued to be point like down to the distance scales you're now probing?
That's the prediction as the data. Completely different.
So it's not certainly not scattering of something point like these distant scales,
and you very much can interpret that as it being actually an extended object, and you can even be more quantitative and get a distance scale out.
So we've got an extended object, it's not like the electrons, it's not like as far as we know, it's obviously made of something.
What is that something? Is it a cloud of some stuff, you know, continuous material?
Is it made of something more fundamental? Well, who knows.
The only way you can answer that question is by looking deeper, going to smaller, distant scales.
And so we come forward to the 70s and the Stanford linear electron collider in California because it's known.
And again, we're colliding electrons with protons. But now at about 40 times higher energy than our original experiment by Hofstetter.
And we look at the same things,
so the electron will scatter off the proton and now the energies are so high that actually it tends to break up that proton,
it tends to tends to destroy it into other particles and you're really seeing inside the proton itself.
And now something slightly at the time, incredibly unexpected and very strange happens, which is that as you go to those smaller,
distant scales, you see a scattering that again looks like the scattering exactly as you'd expect from point like particles.
So this is the plot. This is what it's showing. It's showing a so-called cross section. That's just the rate that the electrons are scattered.
How much are they scatter that each angle and you divide it by the prediction that rather point my prediction?
That is what it would look like. If the proton is a diffuse cloud down to those distance scales, you get less than less scattering.
This is what it looks like, basically flat. Basically, you can understand that point like scattering literally.
By looking at these things, you can see the inside the proton.
There must be some point like objects that electrically charged that we're actually scattering.
So, you know, that's the really compelling evidence that there's something inside the pro-tem.
Of course, there is much other besides,
we knew in the 60s and in the 50s and in the seventies that lots and lots and lots of new particles are being produced in cosmic rays.
We were seeing them in colliders. You couldn't list them all pions on lambdas size, so on and so forth.
And it was completely unexpected. How do you understand this, that these all fundamental? What are they?
How do they interact? And of course, someone had the bright. This cried out an explanation and and showed off.
It had one, which is the from a spectroscopy point of view,
you can understand every single one of these has been a combination of some more fundamental object, which we called a cork.
So fine, you know, did these things exist? Are they just a mathematical object used to describe these things?
Well, people were asking those questions at the time,
but that certainly stopped with a slack experiment to really see that you could actually measure these things and scatter off them.
They were really that forming a proton and the neutron, as we heard.
And we got through three types at a time up, down and strange and more recently, the charm bottom and top.
So we heard from Gavin again, so I won't go through this in detail, but just to reemphasize because it will come up, of course,
as I go on into into and discuss more that the proton is made, it three cooks in the most basic picture to up and down.
These are fractional electric charge. And sure enough, gives us a charge with one proton.
OK, very good. That's that's a that's a kind of cartoon, if you like. But of course, a cartoon only gets you so far.
And there are a lot of questions behind, you know, what is the force behind in these together?
And even if we can put a name to it? How do we actually? Well, we calculate with it, how do we understand what it is and make predictions with?
And this is how we do it. We do it with theory called quantum chromite dynamics.
We heard about quantum field theories in about quantum electrodynamics,
electrons scattering off each other, exchanging other force carrying particles.
Very powerful idea. And the discovery of quarks allowed us to build on that and understand what was binding these things together.
As such, it's such a theory.
So we knew there was a strong force binding the nuclei together because that the proton charge would essentially repel, repel them.
We knew it had to be rather strong, so we called it strong nuclear force.
But until we really uncovered these quarks, this fundamental, apparently fundamental point nine objects within the proton,
we couldn't come up with a convincing theory of the strong force.
But once you had that, you had a fundamental matter particle being the cork, and you could understand it very clearly in terms of that sort of theory.
OK, so that gets us up more or less where we where we where we want to be the LHC.
And so for the rest of the talk, I'll tell you a little bit about actually what we do with the LHC,
with protons and how we can really understand at all what we're doing with them.
So, OK, that's the basic cartoon. Number one, how do we apply that cartoon to the to the LHC?
How do we make predictions? Is there more going on in the proton than that cartoon?
It might be relevant. The Higgs production. The answer is certain yes.
So just to try and give you some idea at a kind of very semi quantitative level about how we understand this.
I'll stick for now with this idea of colliding the electron of a proton and build up a picture of proton and the basic idea as suggested by
that that initial slack experiment was that you don't want to talk about electron proton collisions or proton proton collisions at the LHC.
We want to talk about what you can talk about is rather the collisions of the more fundamental things within the protons and the quarks and gluons.
So that's why we're going. That allows you to make these predictions, but it's not sensible.
I mean, you know, this is a complicated object of corks bound together.
Can you really ignore that fact when you when you in fact ignore that fact, when you when you collide them?
And yeah, the answer is yes, the answer is yes.
And I know there are different ways to get at this, but essentially, in fact, relativity comes to the rescue.
Know there is Einstein looking very happy about that fact.
Very happy indeed, in fact, yeah, it was either that or the one with him sticking his tongue out, so.
Yeah, so right. Think about Proton at rest in Amoco and.
How would that look? It's going to be a dynamic object.
You can have corks, they're going to be interacting, they're going to be moving with a relative motion.
It's going to be a very complicated thing. And now you want to scatter an electron off that and ignore all of that.
And just imagine it just being this, this scatter here. Can you do that?
Do you not need to worry about the kind of coupling all that motion and that interaction with the scatter?
And the answer is you don't. And the reason for that is that, yes, arrest this thing is moving, moving rather fast.
The timescale for these things is that again, not 10 to the minus 24 seconds, a million billion billionth of a second.
Very fast. But nonetheless, there is a time scale associated with it and how you speed these things up to close to the speed of light.
And we have time dilation. Imagine giving the electrons rest, frame a proton rushing towards you at the speed of light.
The clock on that proton coming towards you is going to be moving much slower than the clock at rest,
so that motion or that interaction starts to slow down.
And then it turns out that when you think about that and you think about the time scale that you're actually interacting with this proton wave,
which are called T, cue that it is a lot,
lot less than the time scale that these things are moving around when you think about
that relativistic collision and therefore you're really just seeing a snapshot,
a static snapshot, if you like, of the underlying motion and interaction and you don't need to worry about it.
So as I say, the electron cork interaction time is less than that timescale.
And so it does make sense to talk about an electron scattering more fundamentally.
But is there more to it than that? I mean, clearly I've tried to motivate that there is this static snapshot.
But of course, if you want to understand the scattering, you need to know what that snapshot is of the proton.
What's the underlying prediction for it? What's the underlying distribution for it, if you like?
And again, a little bit of maths, but I will explain it with some cartoons as I go on.
So don't worry too much about that, but you can read everything the relevant variable when you've got two very high energy particles
coming in and colliding is really just how much energy of the cork is the cork carrying,
how much kinetic energy, how much momentum, if you like relative to the total momentum, the total energy of the proton.
And it can even carry all of it, in which Case X would be one where it can carry none of it.
Which case act would be zero? But that's let's break that down a little bit more with some cartoons.
Here was my cartoon.
Here comes an electron scattering off the most basic picture of a proton, and it will scatter off the upper cork site within the proton.
And there is this there is a snapshot. You're not seeing all that motion.
The Electron doesn't see or likely to see something frozen in time comes in and it whacks the book.
Now you do another collision and say what I saw, I'm sorry, what I've shown here is very schematically how much energy is that that caught carrying?
So if you go to the ultraviolet colour coding a lot of energy and you go towards the red carrying less energy.
And you do another collision and it looks different again. You do another collision.
It looks different again. And each time it looks different and you see lots of collisions go back and forward only four of them.
So I have to go backwards and forwards. And you can easily visualise that, OK?
This is quantum mechanics we don't know.
We can never predict that it's going to look like this every time, but that will be an underlying probability, an underlying statistical distribution.
It will look, it will. These will carry more, less energy, a certain amount of time and more energy and other amount of time.
And that will have a distribution. And this is the thing we call a part on distribution function.
They worry too much about the jargon. It's called a PDF, which is not to be confused with a portable document format.
In fact, there is a there is a, I believe, a group that calculates these things in nuclear collisions called EPS.
So it's rather nice joke about encapsulated poster.
But anyway, so yes, that's what we call them.
But forget about the name, really, but I will use it as a shorthand PDF.
It's just this statistical probability distribution. Anushka, you ask, well, how do we how do we measure this, how do we map this out?
And the answer is actually rather rather straightforwardly, at least in the most basic approximation.
And it turns out that if you measure the energy of that scattered electron as it comes out
and you measure the angle that it scatters from just from the kinematics of what's going on,
that it's directly related to how much, how much x how much energy that quote carries.
So we've got to do is we've got to do is build a giant experiment, collide that comes to very high energy.
Then all you've got to do is measure how many times the electron scatter with a certain energy at a certain angle,
and it will be directly related to the underlying distribution. OK.
So so far, so good, but actually not not too relevant to it turns out to what we're doing with the Higgs.
So you need to add the more interesting layers of complication and physics onto what's actually happening in the proton.
So the first step along that is the Proton C satellites.
I have only considered the case of electron scattering scattering off these three that you used.
Because the valence corks within the proton, is that the whole story?
No, certainly not. We know we have Heisenberg's uncertainty principle, something can happen.
Energy, momentum conservation can be violated,
provided it's essentially on a time scale which is sufficiently short enough as set by the uncertainty principle.
And what that means is that in that very strong field of clones,
hawk and anticorpos can pop in and out of existence from that, provided they're only on a very short time scale.
Mathematically, that's how that's expressed. That's the rest mass energy of a cork and an anti cork.
And that is the time scale happened to be sufficiently small.
And you will have heard about that same idea, perhaps people tell you that the vacuum is not a vacuum,
it's full of particles popping in and out of existence. This is rather a similar thing.
Of course, that seems rather indirect. Can we really interact with that while we can?
And here's the very nice idea I told you about the fact that all that motion and those
interactions between the kooks in the basic picture was rather frozen in a snapshot,
and you could scatter off the most centrally instantaneously.
Well, the same is true for all of these cool country corks popping in and out of existence.
So you really, if you can think about it as having a frozen snapshot of all of these cool consequent pairs,
which just so happen to be popping into existence as you scatter off and therefore you can actually interact with them.
So you can't just scatter off the you that basic picture, you can scatter off this whole sea of corks and antiques, and you can measure that.
And once again, you know, the antique walks in the sea can carry different amounts of momentum and you can build up a picture.
So again, the mathematics of this is not too important, what I want to say is that the electron positive electron proton scattering rate can be
written as something due to if you like the scattering rate from those valence quarks,
but also from all of these squawks and anticorpos as well. And you need to include that.
Now we get on to where we really want to go for the Hicks, in fact, which is that I talked about a kind of is this strong glue on it failed again.
Lots of think of lots of balloons being exchanged between all of these courts and so on and so forth.
Very complicated. Get a frozen snapshot of that.
And it turns out you can just as well scatter off those glue ons within the programme so you can imagine a on carrying some amount of momentum.
Scatter off it with a photon, producing a very high energy quote can't quote back flap the proton and again, scatter scatter.
And this has an underlying distribution that you can you can predict or adversary that you can measure.
Right, and there we are. And we're onto the LHC. How does it picture change?
Well, luckily for me and perhaps for you, because otherwise I'd be here for another half an hour.
But the picture doesn't change very much at all at the LHC.
So we're not colliding electrons and protons. Of course, we're colliding protons and protons dominantly.
But the idea is the same. So if you imagine this sort of cartoon of colliding two protons or you've just got an underlying collision
between those that both snapshots again and you just have an underlying collision between them,
the corks or the glue on the corks and the anti quarks within within those protons.
So a simple example is the so-called rally and process. Those are just two physicists who came up with this idea and anti-cult from one
proton from one proton could annihilate an empty coke from another proton.
Produce a virtual photon, which is just an existence for a very short period of time.
And out of measure, let's say, an electron and a positron. And here is the Feynman diagram.
Here is my cartoon equivalent. And that's really what you're interested in.
If you want to predict, is that a little bit there? And those are these distribution functions I talked about.
OK, so what, what what do I do, what other people do? How do we use all of that to do something at the LHC?
How do I put another way?
How do we determine these PDFs or how do we how do we predict what these underlying distributions are going to be that we really need to know?
Clearly, if we're going to predict anything at the LHC? The answer to that is essentially we can't.
And that is because the strong interaction is in the relevant energy regime, strong.
And so these Taylor expansions that Gavin told you about cannot be applied.
And if you can't apply, those becomes very difficult.
And so all of that messy problem of understanding how these corks are moving around, which you then accelerate up and take a snapshot of.
Conflict it. But what you can do is use these things are universal.
The same here, here and here,
and therefore you can measure experimentalists can measure these things in electron proton collisions and also at the LHC.
And you can use that to try and extract them and use them as an input for things like this Higgs production.
And. So where are we today? Yes, what I you open questions, what are we trying to do here?
I've talked you through the basic picture and to some extent that basic picture has been known for quite a while.
But what hasn't been known for quite a while is really precisely what the structure of of of all of those different elements is.
And that's really what we want to know if we're going to do precision physics at the LHC. So there's a whole list of questions.
You know what? I expect you to read them all, but it's just, you know, how much energy is carried by the court, the gluons and the C.
Maybe? What about these heavier corks? I mentioned strange charm and bottom.
They can be in there as well, and you need to understand them for many things. And how well do you understand the connexion?
Theoretically, between everything I talked about in a rather cartoonish way,
a very precise level between the collision and these PDX working all of that out is
what we really need to know to understand Higgs and stress test the standard model.
So we have things called global PDF fits, so fits the parts on distribution functions, fits the proton structure.
And since the discovery of corks, what's really helped here is that there's been a vast array of huge collider
experiments and elsewhere which have allowed us to really map out what is,
after all, a very complicated internal structure with many degrees of freedom.
And that's the way we can do it.
So we combine all of this, you know, the the Tevatron collider at Chicago that used to run that collider protons and antiprotons,
the hara collider at Hamburg, which collided electrons and positrons of protons.
So rather like that deep and elastic scattering process, I talk to you about exactly exactly that process.
And we put them all in a big in a big fit. We try and understand every single one of these processes well enough to fit it.
Of course, you can't read this and I wouldn't want you to. But every single one of these is a given process like of an experiment.
It goes into these things. It gets very complicated.
And here is the data that actually goes into it, and here we are today that really unlike we've ever been before, the data is incredibly precise.
This is really being driven by the LHC, and it's really allowing us to therefore pin down what this proton looks like.
So we have data from Atlas. We have data from at KB, data from CMS, three of the four experiments at the LHC.
We also have data from H1 and these those are experiments that Heracles I talked about.
And there's a lot and I'm not going to go through what each of these is.
It's not important for the current discussion, but what what is nice to see is really the precision the the error bars on these data,
you know, they are, they're just so small you can't see them the kind of cheats a bit because it's a log scale on about 15 or so magnitude.
But take my word for it. Very small. OK, well, it's not just experiment theorists.
And the theory is to match this level of precision, we were going to get nowhere. And it has and we'll hear more about that from Fitbit CEO.
So calculations of these processes that we want to put into the fit, we need to understand well in that Taylor expansion,
we had a gap and talk about where we really it's a very complicated thing.
And so this is this. In fact, this is a distribution to some prediction for that trillion process.
I talked about the electron positron production process essentially versus the
angle that those electrons and positrons get produced out in the collider.
Leading order is the first order now for us. Next to leading order is the second order now for us.
And next, the next leading order is the third.
I think that should probably be for us squared, but no one knows that better than the experts in the audience.
But anyway, you're adding in extra powers in our forecast, you're getting an increasingly precise thing.
Who cares about that? What you care about is this.
Look at the theoretical uncertainty band as you get to that order one percent level, and it's a massive improvement from where we were in the past.
And, you know, I'm not going to even begin to talk about what a five minute contribution to a low end,
non single anomalous dimension in QC is, but it connects.
It's one of those things that connects the PDFs to the processes we measure. And it's rather complicated.
And this is the kind of work you need to do if you can, if you can understand these things. OK, so where are we now?
We've got all that precise data. We've got all that precise theory that's allowing us to pin down this protein structure.
And, you know, two decades after Discovery, which is when this plot roughly speaking was made,
we still only had a very rough picture of how these things looked. And then here we are today again.
I've obviously cheated because a large amount of that is because this is a nice colour plot and that is a grainy black and white plot.
But it's not just that. I mean, don't believe me.
For example, one example because these are rather similar, and don't worry, I will break down everything is in a minute.
I'm on the left hand side. These are just lines that they don't even have uncertainty bans on them.
So they just wasn't enough knowledge, theoretically.
And from data to even say actually, how much wiggle room is there for each of these distributions, how much could they move?
These were just sort of best guesses. Very hard to do precision physics, if that's what we've got.
And today, these are the uncertainty. Bands are not just line thicknesses.
They're really known. It's not precision. So just breaking that down a little bit more,
what does the programme look like here is that distribution and here is the basic picture recovered from this, this plot here.
So this is one of the collaborations that fits these things that could animate that.
I'm the H and. It was actually involved in doing all of that work.
So even today, of course,
with all of the extra precision and the bells and whistles and the extra data when you break it down and you look at the so-called balance structure,
essentially the difference between the up and the ante up. We certainly do see under all of that mess the underlying you picture.
You see a new balance that is twice as big as a down balance roughly two years or up in one day.
And you see that, roughly speaking, to carry about a third of the momentum.
So that basic picture of an up and up and down twice as many ups and downs or carrying about equal amounts of the energy of the proton is there,
but rather clearly there is a broad distribution. So this this is the exhale that's that's been cut off, unfortunately.
I'm. What about forgotten gluons? That's what happens.
So. It's huge. This is the contribution from those gluons that you can scatter off within the proton.
Absolutely huge. Absolutely dominant. In fact, if you work, do the maths stick.
Merck carries about 50 percent of the proton energy to 50 percent of the proton energy that actually is carried by gluons a very important role.
We collide them at the LHC, and that's precisely why we can really study these things.
Study Higgs production, glow and fusion. You've got that that big flux, if you like ugly ones, that we can collide.
So breaking that down a little bit more. We have a plot here from another collaboration site called NPD.
So I'm not going to be biased.
Let's let's go beyond the 50 percent figure, which is, of course, rather rough and not enough for what we want to do at the LHC.
And let's let's let's talk about how well we know it.
So this is just the plot of the uncertainty on the one from dominantly from experimental sources, the data going into the fit.
And there is that baseline. This is a very recent fit, including lots of that actually data.
And what you can see is and this is the reason relevant for the Higgs. So turns out, percent level uncertainty to do very nicely there.
And that's for you. Lots of dedicated work. But why are we doing less nicely? It's a high x said high x.
And what is that? That's high energy. That's high energy Parsons Gap and talked a little bit about physics beyond the standard model.
Well, if you wanted to produce some sort of physics beyond the standard model, it's going to have to be pretty heavy or we'd have seen it already.
And to produce something pretty heavy, you need to collide.
Things are pretty high energy and therefore it's precisely in that region why that would happen.
And yet we have rather large uncertainties. Basically, so far, the data runs out.
So the name of the game there is to really try and pin down as much as we can what
the uncertainty is to really predict how something would look for new physics.
And the other point to make is that we have two curves here, one without LHC data,
and you can see that actually LHC is having something of an effect already.
OK, so the final element is we put the Cork C in these here.
There's no need to break down what each of them is. It's just each is a different flavour of cork up, strange and so on.
But you can see they were broadly the same.
And once again, the only thing I want to point out here is that they clearly some regions carry a lot more momentum and that basic picture.
So again, they're going to play an important role. And sure enough, they do for various LHC physics.
And again, we want to pin those things down.
And if you really stare very closely, you can see that in some cases, indeed, the uncertainty bands tend to be a bit larger than.
OK, so I'm coming to the end. A shopping list of things just to give you a flavour,
not to go into the detail of all the various questions we now need to think about in the future with regards to understanding proton structure.
As I've perhaps given an impression, it's a rather complicated task, including all of that data.
Understanding it all also computationally,
just literally using the predictions that it can be very slow to run and hard to to do to deal with a lot of resources dedicated to that.
And it's not all rosy. What if this high precision data doesn't agree with your prediction?
How do you deal with that? Is that some bias in your your fit? Is it new physics?
What is it? And that's going to that's already some, some some hints of that sort of thing are happening already.
And if we're going to claim such high precision, are there any other theoretical so-called theory uncertainties that we've missed?
I have to go back and re-evaluate the basics and find a nice thing to talk about.
It's just a mention, at least, is that I told you that we couldn't calculate these things.
This part in distribution functions, that's only half true. We can do with consider the strong interaction in the regime.
It's really strong. When we can't use that Taylor expansion in the way we do that is to break down
space time into lots of disparities points try and solve on a giant supercomputer,
so-called lattice. And if you do that, you can get numerical approximations to these things.
It's the very early stage, the various technical reasons why it's rather difficult to do.
But who knows, in 10 years time, 15 years time, we may not even have to fit these things.
We may be able to actually just predict them. And this is all very important for our understanding of the Higgs.
So I'll leave it there and just say I've hopefully convinced you that we we understand the delicacy.
I say not as a proton proton collider, but as a given glue on collider quote.
Collider report comes equipped collider when we understand that and we can really extract the distributions of all those things within the proton.
We don't need to worry about it. We can start thinking about, well, what happens when we collide gluons to make a Higgs and what cannot tell us.
And that's something that, for example, be telling you about in a minute to thank you.