The Large Hadron Collider launches its third campaign – Palatinate

By Leo Li

Ten years ago, CERN’s Large Hadron Collider (LHC) made the discovery of the Higgs boson – completing the 40-year effort to search for this particle first proposed in 1964.

Ten years later, the Higgs boson has become a central part of the Standard Model, but still remains a controversial mystery. Like all other fundamental particles in quantum field theory (QFT), the Higgs boson is an excitation of its corresponding Higgs field. The Higgs field is subject to fluctuations caused by the particles it interacts with and generates mass through symmetry breaking. The Higgs boson can be seen as a signature of this mass generation process, like the dip in stellar luminosity during a planetary transit.

Yet, for what little we know of this supposedly mass-giving “divine” particle, its state of critical self-organization does not seem to suggest a very stable universe for our sustenance. Born of sci-fi existential terror, the Universe teeters above an abyss of the unknown – it’s either a dynamic multiverse or a raw, unfathomable chaos that lurks and lurks beneath us. Trying to rid us of this fear, scientists are actively engaged in the search for an explanation beyond the Standard Model (BSM) – an achievable miracle. This is the motivation behind the third and most recent series of LHC operations.

This indirectly connects us to the search for a new, and possibly better, candidate for dark matter.

After two long hiatuses, LHC Run 3 aims to beam out the dark mists surrounding the Higgs boson. It focuses on the decay of the boson into particles of matter, typically second generation such as charmed quarks, to elucidate the mass property of the boson. From there, scientists can examine the match, or mismatch, between the obtained results and the theory of the Higgs mechanism, to reveal if there really is something beyond our current physical model.

To achieve this, CERN injects a staggering amount – 13.6 trillion electron volts – of energy into the collisions, so that more highly accelerated materials can produce heavier particles and hopefully new ones. particles. Electronics and detectors are also upgraded to acquire more accurate data. Risking damage to billion-dollar super-devices from dust-like protons and the speed of a comet, engineers work day and night to monitor and maintain the flow of the particle beam.

CERN also expects results beyond shedding light on the nature of the Higgs boson in its most ambitious project to date. The devices are adjusted to compare the concentrations of electrons and muons, in order to explain the matter-antimatter symmetry of our Universe. This indirectly connects us to the search for a new, and possibly better, candidate for dark matter.

Similar adjustments are made to the detection modules to further the ratios of lepton decay rates. While the Standard Model predicts a ratio of one – this is called lepton flavor universality – CERN has found minor deviations from one in past LHC measurements. This third run will help collect more accurate data to confirm if there is a “signal crack” in the standard model.

This will provide invaluable data on the state of matter around ten microseconds after the Big Bang.

Finally, oxygen collisions will be used to study the quark-gluon plasma. This will provide invaluable data on the state of matter around ten microseconds after the Big Bang, which will enlighten cosmologists on the very early Planck stages of the Universe.

As ambitious as the third round may already seem, it should be replaced by the High-Luminosity (HL) upgrade, which should increase collision yields tenfold. After another three-year shutdown, the HL-LHC will resume its activities in 2029. The quadrupole and dipole magnets accelerating the particles in the trajectories will be replaced and reinforced, more efficient power lines will be installed and better beam optics and collimators will be installed. in place. to enable more precise focusing and to protect machines against collisions.

With familiar physics targets, the HL-LHC will see a revolutionary improvement in collision data accuracy, which is particularly important when researching BSM physics. An additional goal is to study quantum chromodynamic (QCD) matter at high temperature and density, advancing contextual understanding of quark thermodynamics.

Despite the excitement that the grandeur of the LHC projects gives us, we will have to recognize the need to be patient and scrupulous when we wait and examine the results; we’ll also have to recognize the earth-shattering repercussions once cracks, let alone irreparable flaws, are found in the Standard Model, exciting as BSM physics seems. It is up to our precursors, to us, to our future generations, to dedicate ourselves to the LHC projects and to the many unfinished works that await us.

Image: CERN under Licence

Maria D. Ervin