In high-energy particle physics, bigger is always better. And the moon is a pretty big place.
This is why a team of researchers ran the numbers on building a colossal hadron collider around the moon's circumference and found that a roughly 6,835-mile (11,000-km) Circular Collider on the Moon (CCM) would generate a proton-proton center-of-mass collision energy of 14 PeV, according to a new study shared on a preprint server.
In case you missed it, that energy level is one thousand times higher than that of the Large Hadron Collider at CERN, if we assume a dipole magnetic field of 20 T.
Of course, this is all theory and math, but with so much commercial activity planned for future missions to the lunar surface, a gigantic science-heavy mission like this is a breath of fresh air.
The Higgs boson discovery has left many unsolved mysteries
The researchers also presented reflections on siting and construction, in addition to machine parameters, powering, and accommodations for building, operating, and testing a hadron collider in the relative vacuum of the lunar surface. "Through partnerships between public and private organizations interested in establishing a permanent Moon presence, a CCM could be the (next-to-)next-to-next-generation (sic) discovery machine and a natural successor to next-generation machines, such as the proposed Future Circular Collider at CERN or a Super Proton-Porton Collider in China, and other future machines, such as a Collider in the Sea, in the Gulf of Mexico," read the preprint study.
As the researchers explain, this is not something to expect this decade, or possibly several decades. But, looking even further to the future, such a moon-encircling hadron collider could "serve as an important stepping stone towards a Planck-scale collider sited in our Solar System," added the researchers. Since the discovery of the Higgs boson by the CMS and ATLAS collaborations of 2012, two primary goals have stood before high-energy particle physics. First, researchers wish to execute a high-precision study of the Higgs and various other Standard Model particles and parameters. Second, they want to create higher center-of-mass collision energies with hadrons, to investigate unexplored parameter space, which could lead to more groundbreaking discoveries of new particles.
New particles may lie in wait for hadron colliders at higher energy levels
The Standard Model is a network of ideas and theory that grounds our scientific grasp of the subatomic world, and describes how particles break down into products like electrons, which happens at the same rate when heavier particles are produced that are much like electrons, called muons. Both of the two goals above lie at the center of next-gen circular collider projects like the Future Circular Collider (FCC) at CERN, in addition to the Circular Electron-Positon Collider (CEPC), and another one that might succeed it, a Collider in the Sea (CitS), proposed to float inside the Gulf of Mexico. These machines might reach center-of-mass energies of 80-120 TeV (with the CitS rated at a possible energy of 500 TeV) — a vast increase compared to the 13-TeV energy of the Large Hadron Collider of today.
Sadly, the condition of particle physics post-Higgs discovery has left several unsolved mysteries in physics, with little-to-no hints about the mass scale of new particles or unseen phenomena that, with empirical proof of their existence, might solve these mysteries. At any energy between modern CERN energy levels and the Planck energy, at 10^16 TeV, new particles might lie in wait. We're a long, long way from making this happen, but understanding what might be done to advance particle physics helps us better grasp where we are today in the advancement of high-energy science, and inform the scientific community on which decisions are best to take us into the future.