4 July 2012 was a historic day for science. The ATLAS and CMS collaborations at CERN (the European Organization for Nuclear Research) in Geneva announced to the world the discovery of the Higgs boson, no less than 48 years after its theoretical prediction. Today, ten years later, we celebrate what marked the end of a long era of searching, but also the beginning of a new era in the exploration of its properties and its implications for physics. This discovery is a milestone both theoretically and experimentally.

Particle physics studies the building blocks of the matter that makes up our universe and the interactions between them. All this knowledge can be compacted into a mathematical model, the Standard Model of particle physics, which is capable of explaining with great precision many of the phenomena we observe in nature. The Borut-Englert-Higgs mechanism is a fundamental part of this model, since without it the theory would tell us that elementary particles, such as the electron, should have no mass. However, we know that they do.

The finding proves that there is a field, called the Higgs field, that permeates all of space and that when particles interact with it they acquire mass, the greater the mass the greater their interaction with the field

The discovery of the Higgs boson is irrevocable proof that this mechanism is correct. That there is a field, called the Higgs field, that permeates all of space and that when particles interact with it they acquire mass, the more mass the greater their interaction with the Higgs field. The Higgs boson is the quantum particle associated with the Higgs field, and the implications of its experimental discovery ten years ago are such that the following year, in 2013, Peter Higgs and François Englert received the Nobel Prize in Physics for proposing the Higgs mechanism together with Robert Borut.

But why did it take 48 years before we were able to observe this very special particle? The answer lies in the impressive technological requirements for an experiment of this calibre. To generate a particle as heavy as the Higgs boson (about 125 times heavier than a proton), the Large Hadron Collider (LHC), the world's largest particle accelerator, had to be designed and built.

An immense magnetic field is needed to guide the protons around the accelerator and this is achieved with superconducting electromagnets, which operate at temperatures of -271°C, making the LHC the coldest place in the universe

Protons are injected into it, spun almost at the speed of light and made to collide with each other. Millions of protons against millions of protons. In these collisions, all that kinetic energy can be transformed into mass, generating new particles. The more speed, the more mass, i.e. we can generate heavier particles like the Higgs. A huge magnetic field is needed to guide the protons around the accelerator and this is achieved with superconducting electromagnets, which operate at temperatures of -271°C, making the LHC the coldest place in the known universe.

A vacuum similar to that of outer space is also needed. Once the Higgs is generated at the LHC, we need detectors to record each collision, to take pictures that allow us to study what processes have taken place. This means different types of technologies for different characteristics of each particle. There are detectors that allow us to find out the electric charge and direction of each particle, and others that allow us to slow them down and measure their energy. And here it's time to analyse the data.

Millions and millions of collisions per second generate so much data that we can't even store it in one place. We store it in a distributed way all over the world in what we call the Grid. The Spanish scientific community is heavily involved in this macro-experiment. Centres such as the Instituto de Física Corpuscular (IFIC) in Valencia, a joint centre of the Consejo Superior de Investigaciones Científicas and the University of Valencia, the Institute de Física d'Altes Energies (IFAE) and the Instituto de Microelectrónica de Barcelona-Centro Nacional de Microelectrónica (IMB-CNM) in Barcelona, the Centro de Investigaciones Energéticas, Environmental and Technological Research Centre (CIEMAT) and the Autonomous University of Madrid, the Institute of Physics of Cantabria (IFCA) and the University of Oviedo, we have been working for many years, designing and building part of the detectors, participating in the Grid and making a very important contribution to the final analysis of the data. More recently, the Instituto Tecnológico de Aragón (ITAINNO) has joined the project. Considering the technological challenge, 48 years does not seem such a long time.

The technological development involved in building such an experiment has a major impact on society. The World Wide Web, the PET (Proton Emission Tomography) scanner for the detection of tumours or hadron therapy for the treatment of cancer are some examples of how basic research has a direct benefit in our daily lives.

Dark matter could be generated in collisions at the LHC and, if we can observe it, we could answer one of the most fundamental questions of our time

So now that we know about the Higgs, what do we still have to learn? The fact that two independent experiments, ATLAS and CMS, observed the same phenomenon left no doubt: a new particle had been discovered and everything pointed to it being the Higgs boson, although at the time we could not be sure that it was the one we expected. Today, after analysing vastly more data, we have a much clearer picture of the particle we first observed ten years ago. The way it interacts with other particles and its quantum properties strongly suggest that it is indeed the Higgs boson predicted by the Standard Model. For this newly observed particle could be the Higgs or a totally new particle.

This week we celebrate not only the tenth anniversary of the discovery of the Higgs, but also the scheduled start of what we call Run 3. The LHC is starting up again after three years of technical shutdown with the plan to collect a much larger amount of data than we have already accumulated. With this data we will continue to study the properties of the Higgs, but it also opens the door to the discovery of new phenomena that could solve some of the mysteries that the Standard Model cannot answer.

We are talking, for example, about understanding what dark matter is composed of, a type of matter that we know makes up about 25% of the universe, which the Standard Model does not consider and which we are unable to observe with the apparatus currently available to science. Dark matter could be generated in LHC collisions and, if we can observe it, we could answer one of the most fundamental questions of our time.

These are such complicated questions that they require a very long-term plan. From 2029, the era of the High Luminosity LHC (HL-LHC) will begin, when the amount of data collected will be multiplied by a factor of 10. Even after this period, a particle collider with a circumference of 100 km is already being planned, which would allow us to clarify all the properties of the Higgs in great detail.

Many of us physicists hope that somewhere along the way we will find a flaw in the Standard Model, which, so far, has been invincibly resistant to the higgs

In fact, there are many physicists who hope that somewhere along the way we will find a flaw in the Standard Model which, until now, has been invincibly resistant. A new phenomenon that explains the aforementioned dark matter, the origin of the neutrino mass or the matter-antimatter asymmetry. I want to be optimistic that in the coming years there will be another great milestone to celebrate in LHC physics.