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So thanks a lot. It's really a pleasure to be here and to talk this morning on the Standard Model and the Large Hadron Collider and the Higgs boson.

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So let me begin the first part of my talk to review something that most of you will know about, which is the start of particle physics.

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I, in connection with previous lectures of this morning that you have had, so James mentioned the quantum field theory, right?

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The standard model is perhaps the greatest success of this very important theory, which is quantum field theory.

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So first of all, let me mention that this is really an extremely exciting time to be a particle physicist.

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Right? So in the last years, particle physics had to be in the headlines several times.

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And this is fully justified by the discovery of the Higgs boson at the Large Hadron Collider in thousand 12 is the most

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important discovery in our field in the last 25 years because it completes the extremely successful standard model.

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But at the same time, it opens a large number of crucial questions for our field that we need to answer.

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And the Large Hadron Collider will play a central role in exploring this high energy frontier for the last for the next 20 years.

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So what is this? I'm not a modest I'm not a model,

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is the theory which explains a wide variety of microscopic phenomena into a single unified framework, which is quantum field theory.

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It describes all elementary particles and their interactions with the only exception of of gravity.

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So what is the standard model composed of? First of all, in this matter, right.

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It describes a protons and electrons and also other of the particles.

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Its content is composed, organised in quarks,

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which experience the strong interaction and leptons which they only experience a weak electronics electromagnetic interaction.

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There are six quarks. They are called up, down, strange bottom and top.

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There are also six leptons, six from the electron familiar with, but it also has two headed counterparts, the new and under and the Lepton.

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And also there are three neutrinos which are massless electron neutrino, neutrino and neutrino.

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And then there are the interactions which relate these particles among them.

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And these forces are governed by the exchange of the so called a force carriers, and that is one force carrier for each of the interactions.

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The electromagnetism is based on the exchange of photons.

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These you are familiar with the strong interaction, as I will explain, is characterised by an exchange of gluons.

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And then the weak force is defined by the interaction, by the exchange of divergence at bosons.

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And the last ingredient, which was found only three years ago, was the Higgs boson,

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which is really essential because it's the way in which all the particles in this field can acquire mass,

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because this mass is forbidden by the symmetries of the Lagrangian.

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So let me begin by recalling where all this comes from, right?

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So let's go to the early thirties. And after a number of very important discoveries, the electron, the proton,

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the neutron and the positron, we have more or less a complete understanding.

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I can read the scripture of particle physics. I do have the atom we had.

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We understood the atom as composed by atomic nuclei of protons and neutrons, and then of the electron electron layers.

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So it seems that more or less things were in place.

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Of course they were important questions, but some people thought perhaps there are minor issues.

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However, the discovery of the moon of 37, which is a heavier electron, basically was completely unexpected.

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Like nobody expected the the moon, as some people put it for that.

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Why do we need to have the electron? What does this state in the scheme of things and to make things worse then a plethora of newer,

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strongly interacting particles called pions chaos was soon discovered.

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So as you can see in this time and here. So by 33 we had the neutron, the positron, but then we had the mean pions cones and then,

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you know, a large array of other particles, lambdas, obstinance.

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And the question is, can we make sense of this really [INAUDIBLE] situation?

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And moreover, many important conceptual questions were left unanswered.

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For example, if you have protons together in the atomic nuclei, they have Coulomb repulsion, right?

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So they should be atomic nuclei should explode. Why? Atomic nuclei are stable.

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What close together protons in the nucleus. What is the origin of weak interactions?

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Which are the life radioactive decays so why we atoms decay radioactively we had no theory to explain this.

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Moreover, all these particles are fundamental. They are composite.

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They didn't have any structure.

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And even more important, which is a suitable mathematical language to describe particle physics is quantum mechanics is something else.

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This was not clear to many people. Now, let me begin with the first thing that actually this is quantum quantum electrodynamics.

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This was well, this is it is the quantum version of electromagnetism.

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So electromagnetism was discovered by many people in the late 19th century, and it describes the interactions of charged particles.

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We had exchange of of photons, however,

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making sense of quantum thermodynamics so making sense of electromagnetism once we called

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quantum mechanics was extremely challenging y because you had to apply multiple infinities.

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When we try to compute corrections, quantum corrections to electromagnetism, we encounter infinities and how to deal with these infinities.

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What have theoretical thought? The force, which took ten years until the formulation of quantum electrodynamics was achieved?

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I'm sure these are very beautiful theory because starting from simple rules, which are called the Feynman rules,

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we can compute any terms as an expansion in power based on the weak coupling.

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The electromagnetic coupling is basically the electron chatter square.

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So these are small number.

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So you can compute the leading term and then subsequently add more and more complicated attempts, each of which will be in principle.

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It's my of the others. They can achieve an arbitrary position, make computing more and more complicated diagram.

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So if I put together all these lines and all these vertices and I do the entire in principle,

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I can achieve arbitrary accuracy in any any process and actually some of the most precise.

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Nations that we have never done have been done with quantum electrodynamics, for example.

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These are quantitative, which is called the anomalous magnetic moment of the moon,

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which equity is known to an accuracy better than one part in 1 billion.

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Imagine this we can compute something with this incredible precision and attack this with experiment.

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It's really a major success of quantum theory. Of course, this is not an easy task.

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We'll have to compute extremely complicated diagrams which involve complex interest.

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But in principle, starting from these rules, everything else is fully, fully predicted.

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Now, what about the poor? How they were just how they were discovered?

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Well, in the beginning of the century, there were experiments discovered in internal structure of of atoms.

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How this this was discovered. Well, so that was the experiment.

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There was a theme, a theme for love of God. And then you had this was bombarded with alpha particles, which basically helium nuclei.

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And we looked at a ruler for look at the reflection of this of these of these alpha particles.

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Right. And by looking at the scattering angles of these alpha particles,

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after interacting with their with atoms, they realised that the atom is not like a pancake.

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The atom is really odd.

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The all the positive charge is constituting a very small volume, which is the atomic nuclei, and then the electrons are around these nuclei.

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So this was, of course, our impressive discovery.

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Very interestingly, 70 years later, the very same technique was used to discover quarks.

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What did we do? Well, in this case, instead of using alpha particles against atoms, we use very energetic electrons and we bombarded a protons.

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Right. And by looking at how the electrons were deflected, whereas when they scatter with a product,

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we discovered that in the proton the charge is also point, like it's concentrated in small volumes.

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And this what is what led to the discovery of of of quarks in there in the proton by the same

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mechanism as the discovery of the atomic nuclei by their in their order for experiment.

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Of course, the concept, of course, had been known for a while.

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Right. Since it seems since the sixties we had the Constitution Park model, which allowed to describe all the all the others as composed by this.

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This. Hypothetical particles, which are called the quarks, like example,

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the proton can be understood as as composed by two apart and one network and the neutrons one upward to the quarks.

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However, these works were very peculiar, right? To begin with, they had fractional charge.

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So they tell us either two thirds or minus one set. And we have never seen a particle fractional, fractional charge.

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So many people was a sceptic and they thought that perhaps this is just a mathematical trick to organise hadrons by physical existence.

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However, after the experiments that I mentioned here, people realised that they are able to play a good mathematical description.

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They are really they have a physical existence and describe their. The structure of Aladdin's soap with just up down a stretch we could describe.

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Essentially all known. No. So again, we had the very interesting surprise winning the 73 to 77.

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Two new, heavier quarks were soon discovered, the Champ Quark, with a mass of about 1.5 and the bottom quark with almost about five g.

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So this is there in this spot here, you can see that their discovery of their channel.

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So how these things were discovered, we had an electron positron collision.

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Right. And we've vary the mass, the energy of the collision.

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And at some point we see that there's a peak. Right?

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This peak is indicating that in this collision there is a particle which has been formed with Hamas around three TB.

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This particle was called the jape site, which corresponds to a mass of our time.

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And so this was the discovery of the Templars in 73 and there is an even heavier support of 475 times.

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The proton mass is it's a single particle which is almost 200 times heavy on the proton.

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Had to wait until 1995 to be discovered because it's being so massive.

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We need very high energy colliders to be to be able to. To detect it now.

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So I've thought about quantum electrodynamics, this activity spectra.

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But if I can compute terms because the coupling is small, I can just compute 10% expansion in orders of this coupling.

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So this, of course, makes a theory very predictive. I thought my Feynman ephemeris I can draw diagrams for any process.

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I can compute the corresponding cross-sections. However, the atoms interact strongly.

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Right? The interaction is characterised by if like it's coupling is something which is very strong.

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So it seems that the model of QED is of, of affirmative quantum field theory is not applicable and that we need something else.

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And people working this are extensions of like a theory or its matrix.

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However, a breakthrough came in in 1973 when it was realised that there was a theory that could describe the strong interaction.

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At the same time, the attractive theory is called quantum thermodynamics, and quantum computing has a very peculiar feature,

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which is the following, which is the strength of the strong interaction.

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So this is the value of the QCT coupling as a value, as a function of the energy right in the remains able quantum of series,

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the value of the couplings around this with the energy. This is the three romanisation group equations.

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Now, if you look at low energies, for example, well below the proton mass,

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this coupling is very large and the theory is strong, interacting as all the data suggested.

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However, once we look at very high energies, for example, 100 times the proton mass,

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the theory becomes quickly weakly coupled because alpha is a small number.

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And in this regime, what I'll face is a small.

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We can just exactly the same techniques as what QED to do to computer, to compute predictions for physical observables.

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And this was verified to very, very high accuracy.

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So again, quantitative theory is the right language to describe not only the electromagnetism, but also the strong interaction.

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So the strong interaction, say, QED, has the photon. In the case of a you see we have the gluon,

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which is the particle that made this interaction and is responsible of binding together the quarks in there in the proton.

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And this you can understand that easily. So we see that the strong interaction is something that the coupling but also with the energy.

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Right. We know that even in quantum mechanics growing with the energy, so it's more energy to correspond to larger distances.

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Now, imagine they have two quarks and they have they are very close together.

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If they are close, it corresponds to basically large energies.

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So the copying is small, but if I tried to pull them together, so I pulled them apart.

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Sorry, their distance will increase. At this point, these correspond to lower energies and they will become a strong.

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So the fact that the coupling is large is large. A small energies for large distances implies that we cannot have quarks isolated.

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They will always be bound together because this coupling is very large.

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Now, the gluon was also discovered but also verified experimental its existence in 1977 and this is called three jet events.

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So the theory of the strong interaction predicts that if we collide electrons and positrons,

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some of the events that we will see in our detector will have kind of mercedes's shape.

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You have to quirks here. And then there's a gluon recoiling and this is exactly what was seen.

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So this would be awkward yet quartette the yet.

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So again this provided an extra evidence that electricity was the right theory for the strong for the strong interactions.

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Now going to the interactions with interactions are something that was having known for

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a while because it's allowed to explain the idea of metallic metallic of of nuclei.

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Now, in the 1930s, Fermi explained the metallic of nuclei by full body interaction.

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So basically you have a neutron and these news on the case into a proton and neutrino and the electron in out for body interaction.

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So therefore the atomic number of this nucleus would change by what one unit as modified in better metallic experiments.

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So it seems that these are also very different from the strong, from the it from QED, right?

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Yeah. There is no particle mediating this force.

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So what's it is possible to describe the weak interaction in the framework of this quantum field theory?

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And the answer is yes.

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And the point is that as opposed to the blue one and the photon, which has no mass, they are massless the carriers of the weak interaction,

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which are the WS and their bosses, they have a very massive they have a mass of almost 80 GBPS, so 80 times the proton mass.

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Therefore, if you look at weak interactions at low energies, you would never resolve the mass with just a point interaction as once you hear.

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But if you go to very high energy,

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you will see that actually there is a particle propagating like just like the photon or it, but that is very massive.

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So in the standard model, the weak interaction of Fermi can be seen as here.

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So we have this ah neutron composed down, up, down.

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These are proton composite, right down, up, up. And then the down emits the larger you boson so transforms into an output and it will

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give us some indication for the electron unable to do so exactly as s as Fermi had.

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But now in the context of that, nobody is able quantum theory.

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So also in this in the seventies, the fact that this theory was the right explanation of the interactions was verified.

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So, for example, the discovery of neutral currency neutrino scattering.

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So you have high energy beams of neutrinos which you point to some target, and then you try to reconstruct the results of this collision.

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Now, one of the predictions of this was that the neutrino there would be neutral patterns in the sense

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that the neutrino will interact via the neutral particle that and then hadrons would be formed,

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but no other charge that happens. So these the neutrino these are the traces of the of the evidence for the collision, but there's no charge at level.

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So you have neutral currents. And then you also mentioned that the analysis of this kind of images was done among other places.

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Know what we are speaking now, which had a crucial role in the discovery of that of the neutral currents.

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So we have seen the electromagnetism, the strong interaction and the weak interaction.

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What is the only missing piece? This is the the Higgs mechanism. Right.

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So what's the problem? Well, Julia will talk much more about this.

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Let me just explain it briefly. So the problem is that in the standard model, its symmetries don't allow to have mass in the Lagrangian.

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Right. So in particular, we have a electroweak.

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A Electroweak theory has a asymmetry between left handed and right handed particles, which for beat the particles.

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So what is the Higgs mechanism? These are very clever trick to bypass the restriction, because in the Higgs mechanism the laws are still symmetric.

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But the configuration that nature has chosen is not symmetric. Right.

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Is this is the famous Mexican hat potential.

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Right. If you look at this potential, this potential exploitation, asymmetric, right.

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Any direction looks the same. However, the point where the Higgs field just has to be is not is not traditional

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symmetric is just one point of all the possible end points of the of the minima.

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So these are spontaneously symmetric breaking that laws asymmetric.

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However, the specific configuration of the vacuum is not.

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So it's actually a mechanism that all the particles in the standard model can operate en masse.

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And it's a crucial product. If the energy of interaction is high enough, we can excite the Higgs field.

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And excitations of this Higgs field are the Higgs particle which can be produced.

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And that's the ultimate test, that this explanation is the right one,

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that the Higgs mechanism is correct description of the mass, and the model is the discovery of the Higgs boson.

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So it was predicted more than 50 years ago,

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but it took an impressive and impressive effort from theories that experimentalists to be able to develop the calculations

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and the machines to be able to finally vindicate this prediction and was discovered two years ago at the Lateran Collider.

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Okay. So this is the standard model. Let me move to the second part of my thought.

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How can we explore the high energy frontier? And this is the best machine we have nowadays to explore the frontier.

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Is there a Large Hadron Collider?

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So, first of all, why do we care about high energy colliders, what they are suitable to explore really nature at the smallest possible distances.

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But we know from the Heisenberg Principle this is there was a question here that if we want to prove something which very small resolution,

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we need to have a proof which is very energetic. Right.

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So if we want to resolve an object to very small scale, we with a particle which is very energetic, if not, it will be impossible.

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So a rule of thumb is to convert distances in energies is the following.

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If I have a particle with one GV, this corresponds to roughly a distance of a .8.42 ten to the minus time into a matter of 50 metres.

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It's called 0.2 pendulums. This conversion sets the energy that we need to more or less use to explore smaller and smaller objects.

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Like, for example, a an atom has a length of about 10 to -8 centimetres, right?

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So we need energy of the earth at about 2.5 million to exploit a structure.

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If we want to prove the structure of an atomic nucleus, this is an object of about ten to the -40 metres.

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We energies of the order of 200 amoebae, which makes sense because these are typical energies which are that are relevant for nuclear processes.

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If we want to go to even smaller distances in particular to to prove the structure of the proton, we need a particle has energies in the GBE range.

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And this was precisely by the experiments in like a ten GB because this is right energy to be able to resolve the internal structure of the proton.

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If we want to go further and explore, for example, if electrons or quarks have a further structure,

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then we need to prove energies because a quad is known to have our radius of a smaller than 10 to 16 centimetres.

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So with energies of of two TB right. So if we want to reach really the smallest possible distances, there is no other option.

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But going to that to these wide the LHC collider that is bring the escape.

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No high energy carriers have been around for a while.

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Right. The first collider was there, the Lawrence cyclotron in Berkeley.

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And as you can see, by the standards that we are now used to, it is just, you know,

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it's almost at that point, right, is only 1.5 metres and the energy seems very small at 15 maybe.

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But this was really crucial, right? Because this was the first time that in a controlled setup,

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you could accelerate particles and restore its results without a with without the collider.

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What is the problem? And we want to use we can only use cosmic rays, for example, or, or that natural process.

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So we cannot control in detail which are the settings of our collision.

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And this is of course not good for extend our point of view.

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We want to control everything. And in the case of our cyclotron, we have all the activities that we want to to control the energy of the collisions.

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And then these are very clean proof of air. Of our experiment.

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So they have many other colliders being built. And then I would just highlight three of them.

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One of these is it's like this the Stanford Linear Collider with a length of three kilometres.

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This is in in California. And an edge of 98 is a linear collider, which means that I collide electrons with positrons.

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These are very clean experiment. However, it switching energies limited.

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There's also the collider in Amber, which was the first and only electron proton collider ever built.

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So we have a high energy beam of electrons colliding with a high energy team of protons, the length of six kilometres and the energy of 210 GB.

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And then there was the platinum collider in Chicago, which was before the energy was the highest energy collider of the world,

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which is a proton collider in a tunnel of six kilometres.

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And the energy you have out to TV. Each of these experiments has provided us crucial information of the standard model.

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But since a some years, some years ago, we have the Large Hadron Collider really and is an impressive machine.

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Right? It's the most powerful accelerator ever built by mankind.

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They taught it at CERN in Geneva, which is the sun, is the European Laboratory for particle physics.

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So it's composed by a massive 27 kilometre long tunnel with four gigantic detectors in them.

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So this is the this is a photo taking of the LHC area.

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So this is the Geneva Airport for those of you that nobody at the Geneva.

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This is where seven is located. So my office used to be here for three years.

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And then underneath all this area, there is a Large Hadron Collider. So these are the SPS.

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And then this is the LHC tunnel that goes almost from the airport to the lake.

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And then today I'm on the other side of the lake.

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And identity of the protons attacks had the highest energies ever approved with the goal,

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as I was mentioning, to explore the laws of nature, the smallest distances ever achieved.

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So in the LHC there are four massive detectors.

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They are called Atlas CMS, satellite TB.

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You can see, you know, by comparing with the size of a of a of a person, they are really they're really massive.

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They are like six, seven, eight story buildings of an amazing technology.

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I'm always impressed that these things even managed to work. Right. You have something which is huge as a building.

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Everything wires and detectors. And, you know, it manages to work on two quite impressive measurements.

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I think that's the technological is an impressive achievement.

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So I say, well, I also wanted to mention that Oxford has played the central role both in building

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these detectors and now in operating them and extracting the most of that information.

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The galaxies are an impressive machine, right?

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But without its detectors, which are able to explore, you know, and able to extract information from the collisions, then it would be useless.

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So we thought the detector, having very energetic protons, is not very useful.

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So let me show how articulation looks like. So these are nice video done by their Atlas collaboration.

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So this is the LHC tunnel. Right. So here you have there we have that protons, which are actually a very, very high energies.

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Right. So let's go inside the beam. This is the proton composed by in this video by three quarks.

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And the proton is six and eight of them. At some point the beams will cross.

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Right, and they will cross in the interaction points whether that they are located.

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So we have their proton beams, they get close to each other, and then eventually they collide.

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And what the detector does is by reconstructing the traces of the collision, reconstructing the hadrons, the leptons, the most, the missing energy,

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that the aim is to reconstruct what has happened in this interaction point, because this interaction point is that collision of very high energies.

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So therefore, here is precisely what we are calling nature at the smallest distances.

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So let me mention some facts about the LHC, which I think are quite interesting.

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So first of all, LHC is one of the coldest places in the universe in order to keep it in magnets.

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So it is based on semiconductor superconducting magnet in order to keep these magnets operating with very, very low temperatures.

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So the LHC will have a 30 kilometres tunnel just kept at only two degrees above absolute zero, which is, you know, it's called the interstellar space.

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Another interesting fact is this is one of the empty space in the solar system.

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Why? Because if in the beam where we have the problems running, there is even a very small density of air particles.

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The problem we've had with these particles and we will not be able to explore the in the detector.

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So we with really a very, very high vacuum like us.

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Another interesting fact is that it's one of the hottest places in the galaxy.

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So, for example, when we collide, heavy ions like for example, that in the LHC,

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the temperature that we generate is an example of these collisions are billions of times larger than in the sun.

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Right. Which is the conditions similar to those in the very, very early universe.

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And also a final score. They think it's really impressive is the amount of information that we extract from the LHC in just one second.

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The LHC in principle could record one third of out of data just per second.

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Right. So this is like having to record 10,000 sets of Encyclopaedia Britannica per second.

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So it is it's an impressive technological challenging to be able to efficiently skim all this huge amount of information for the relevant events.

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So what bility has has what have we learned fertility up to now?

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So the first result has been that rediscovery of this model.

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What do you mean by rediscovery? Well, in the previous slides I mentioned the discovery of the deep sea obsidian as a particle.

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The very first thing that DDT had to do is to check that everything was still there.

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And this might seem obvious, but it is not because this machine is technologically very complex.

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So first of all, we have to validate that everything is in place, that the detectors went to the detectors, its performance.

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And also, we need to check out our calculations, which have been tested before at lower identities.

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Also hold high energies, because we are these are very largely average.

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That's increasing the energies. So the in this book here by this collaboration, this is a plot of the.

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This is proton proton collisions into the news in this case.

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And each time we see a peak, it means that there is a new particle has been produced in this collision.

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So, for example, if we look at around three, three gbps, we see a peak.

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This is a site discovered in 73. If we look at above at 1022, we see the epsilon.

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This is bottom 90, both the mission discovery in 77 and then at around 100 GB that does have mass, right.

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It was very nice to see that no ability.

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We can quickly rediscover the oldest under model and test our calculation with a very high degree of accuracy.

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And this is very important because predicting the standard as well as just passing predicted processes with

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very high accuracy could be the key to discover new physical reality in there in the following years.

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Of course, the biggest achievement of the LHC has been the discovery of the Higgs boson.

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In this video here, I'm showing a collision in which a Higgs boson candidate is being is being formed into four into four leptons.

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So each of these four lines is are four leptons,

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which is one of the cleanest channels of the production of the K and Julia know talk about this later.

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And this is a extremely challenging measurement, right? Because it requires to disentangle a very small signal from of a large background

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and to try to to convey the message of how challenging these measurements are.

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Let me show you an extended mission by the Atlas collaboration. So how we discovered the Higgs from the practical point of view.

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So we begin without any data, right? And we want to measure two things.

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One, to measure the masses of default numbers so the Higgs can decay into pairs of photons.

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So if we look at beta photons and compute the mass, if we see a peak, that would be a discovery of the Higgs boson.

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The same the Higgs can be came to four letters.

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So if I compute the mass of four atom events, which is not in this model, will be evidence for the Higgs.

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Right. So let me begin to take data. So slowly I began to accumulate data.

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But here there's nothing, just a flat line. So just background. But with more and more data, right?

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Something will appear. What will appear? There's a structure forming here, right?

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And what is this structure? This is a peak around 25.

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TV is very interesting because this is this could be the mass of the Higgs boson.

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Now, is it really the Higgs boson could be something as a statistical fluke?

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Well, what we do is to go to the other process, which is going to four leptons and also big data here.

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Right. So I'm taking data in the Higgs into four letters to begin with.

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I don't have anything. So I need to more and more data. Everything looks under model no Higgs.

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But eventually there are some events here that hey, they are their mass 125 GV and they are not they are not.

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Some said that for example, this could be a Higgs.

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And the crucial thing is that this signal here has a peak at exactly the same mass as they're wanting today for the channel.

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These are very strong. Check that this feature here, this feature here correspond to the same logic like this,

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that the Higgs boson and actually at the at the LHC, these two channels, two forms, four letters.

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What are the ones that we are able to proclaim our discovery in July 2012.

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So it really this is why after this massive exercise, we can be happy because we found the Higgs boson.

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No. Okay. However. Some of our models is an impressive success and we should be really proud of.

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It is one of the greatest success of modern science.

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However, despite its successes and discoveries, Higgs boson, there are many crucial questions which are still left open.

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For example, the stability of the Higgs Mass. Why the Higgs Mass is what it is and not the mass of the mass at very, very high energies.

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What is the nature of dark matter or that cannot see those forces unify into a single one?

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So our strong interactions with interactions and explanation aspects of the same force or they are not.

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Is there a theory of everything? What is the role of gravity? Because the gravity doesn't fit in a standard model, right?

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What is the origin of the matter? Anti-matter asymmetry.

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So there are many questions which are really crucial that have been not that are left open by another model.

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And the interesting thing is that there are many theories that go beyond the standard model, and many of these can be tested at the LHC.

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So the LHC is a unique tool to scrutinise these theories, which will try to attempt some of the limitations of the standard model.

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One popular example that you might have heard about is called supersymmetry.

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So in supersymmetry, each particle has a super partner. So we have talked about quarks, neutrinos, the force carriers and the Higgs boson.

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So in supersymmetry, we have the standard model and we have another copy of all the particles with the spin the force by one half.

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So you have the force which had us no fermions anymore.

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We have this leptons and then we have the the best symmetric version of the case, Boston Dynamics of the Higgs, which is called the Higgs.

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And among all the things that have been predictions of supersymmetry,

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it predicts that all the free forces are strong with magnetic, if you will, two very high energies.

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They become just a single, single force.

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So this what is called a force unification, which is, of course, a very attractive theory out of a fundamental theory of nature.

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However, as of today, there are no hints of yes in physics ability.

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However, in just a few months, data will have started even higher energies and will have ten, 15,

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20 years to keep exploring the high energy frontier and try to understand all these pressing and very important questions.

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So I think that it is very likely that we have many new breakthroughs and we are on the corner.

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Okay. So in the last 5 minutes, I want to mention what's next, right?

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What's what's beyond reality? And this is important because in high energy physics, building these facilities,

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since it's really at the cutting edge of technology, it takes long timescales.

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Right. Both from the civil engineering to a technology to or to the physics,

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say something that even if we are only at the beginning of the LHC problem, we have to begin to think what comes next.

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So this is the scale of the LHC for the next 25 years.

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So I'll say what's amazing, they deliver a huge amount of interesting results, but we are just at the very beginning of the problem.

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Right. So we have seen how they can data for three years at seven TV and a TV reality has some that are going along shut down of two years.

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And now we are here. We are about at the beginning of day, which is called rental, where the energy has increased from eight TV from 13 to 14 TV.

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So there will be a period of about eight years of running for TV and then there will

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be a very important upgrade in which the LHC will be turned into the high luminosity.

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LHC What's a high luminosity?

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It's only the number of collisions per bunch crossing will be increased substantially, so increasing the chances of finding interesting events.

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So we have half work for the next 20 years to really try to explore the high energy frontier.

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And the LHC is the best machine that we have for this. And something which is crucial, especially in the lack of any evident signal of BFM theory,

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is to try to sharpen our understanding of the weak interactions, electromagnetism, because this would be the key of new discoveries.

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New discoveries would appear as a subtle deviation from some normal prediction.

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So the better you can compute things with high precision, the closer could be to a new discovery.

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At the Large Hadron Collider. And of course, it's essential to have a very close interplay between theory and experiment.

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Right. And two of the central ingredients of the LHC program for the next 20 years.

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Well, first of all, precision measurements of the Higgs couplings. And Julia will talk about this in her talk.

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And then the search for dark matter. The LHC and Woolly again will tell us about this.

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So as I was saying in about 2022, we have to upgrade the LHC and turn it into our high luminosity machine.

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What's the high luminosity, as it was mentioning, is now in the municipality.

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The number of collisions that a bunch of crossing would be much higher, which means that the chances of finding interesting events will be larger.

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Of course this has challenges because if you have more collisions, you have more single events,

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but also many more background events like these because this looks extremely messy.

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We have to extract interesting signal in a in a collision where we have almost 200 collisions, literally a background noise and need to be removed.

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So this requires a complete upgrade of the LHC detector.

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And also here, Oxford is studying a central role, in particular in the case of Atlas in building the new Atlas Atlas Silicon Tracker.

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And so let's try to think even bigger. So what comes in the next 20, 30 years?

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Well, as I was mentioning, the planning of these facilities is always an expression of very long timescale.

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Right. Because we are at the cutting edge of technology, of civil engineering.

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You know, there are problems that these machines are planning the solution.

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So we to think we are out of time. So in particular now we are discussing whether the next peak machine would be 100 TV.

390
00:36:51,100 --> 00:36:54,400
Collider So seven times higher than the Large Hadron Collider.

391
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Also, we have electron positron, an electron proton model. This is called tentatively Future Collider and this is the plan of a possible site.

392
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This would be again in Geneva. So is the LHC tunnel.

393
00:37:08,350 --> 00:37:12,430
This would be the 100 kilometre long tunnel where this could be built.

394
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So you see that it's quite impressive that as compared to the FCC, it's very small, despite being an incredibly large machine.

395
00:37:20,590 --> 00:37:26,230
Also sites China is very interested in this kind of projects. And there's a proposal for the FCC in China.

396
00:37:26,860 --> 00:37:29,290
And now in the context of of working groups,

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there is a worldwide effort trying to understand both the technical feasibility and the physics motivation of this of this proposal.

398
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There are also other ways that we could explore the hydrogen from the earth.

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For example, there are plans to build a linear collider where you have electrons and positron collisions at very high energies.

400
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For example, there is the plan of having click in Geneva.

401
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It would be a linear, linear tunnel that goes from the French part of the French area to almost all given crossing all the Geneva area.

402
00:37:59,680 --> 00:38:04,540
These are cleaner machines because electrons are fundamental constituents, so there is less background noise.

403
00:38:04,870 --> 00:38:08,110
However, they have greatly reduced reduce friction.

404
00:38:08,970 --> 00:38:15,550
In. So I think that I've tried to convey that this is really a fascinating time to be in particle physics,

405
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that this has been an incredibly successful theory and that it will be the

406
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best tool we have to explore the high energy frontier for the next 20 years.

407
00:38:25,810 --> 00:38:29,590
I think that you should really stay tuned for news for the LHC because I'm sure that

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there will be very interesting results from us and you will be happy to have them about.

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So thanks for your attention.