Why ‘magnificence factories’ might clear up two large cosmological mysteries

Do you know that, in physics, we’ve got magnificence factories? This has nothing to do with artwork or glamour. As an alternative, I’m speaking about experiments the place electrons and their antimatter counterparts, positrons, are collided collectively to supply particles known as B mesons.

These are product of quarks, the subatomic particles discovered inside bizarre matter. However whereas such matter is nearly completely composed of electrons, up quarks and down quarks, a B meson is made up of a magnificence antiquark and an up, down, allure or unusual quark.

This make-up offers B mesons a particularly brief existence, far faraway from every day life, so that you may marvel why anybody would trouble devoting entire amenities we now name B factories to creating them. The reply is that B mesons may help us clear up a giant thriller of the universe: why there may be extra matter than antimatter.

We all know that each kind of particle has an antiparticle, however once we have a look at the universe, we largely see particles, not antiparticles. So the universe seems filled with electrons, however not of positrons – equivalent to electrons, however with an reverse cost.

Mesons are attention-grabbing as a result of they exist between matter that’s considerable within the universe and antimatter, which isn’t. As such, we could possibly exploit them to study extra in regards to the asymmetry between matter and antimatter. Understanding this may clarify why there may be something lasting within the universe in any respect, since matter and antimatter are inclined to annihilate on contact. We create B factories as a result of they may help us clarify why the universe isn’t empty.

Issues get much more advanced when you think about that mesons even have their very own antimatter counterparts. Every B antimeson is product of a magnificence quark and an up, down, allure or unusual antiquark. Within the case of B mesons made with unusual or down quarks (often known as the impartial as a result of they don’t have any electrical cost), the particles oscillate between being mesons and antimesons. In different phrases, impartial B mesons are spontaneously non-binary.

It’s these impartial B mesons which can be key to understanding the matter-antimatter asymmetry. Though their non-binary nature is a prediction of the usual mannequin of particle physics (which catalogues each particle ever seen), we are able to look to see whether or not the oscillations are precisely half and half. Are the particles we first make within the collisions extra prone to be mesons or antimesons? If there have been an asymmetry in these oscillations, this may clarify the matter-antimatter asymmetry.

In 2010, researchers on the Fermilab DZero collaboration claimed to see a 1 per cent distinction, however no different work has confirmed this end result. The chance stays intriguing, particularly since analysis not involving oscillations has definitively noticed variations.

B factories can also assist us perceive one thing we’re sure exists, however have by no means seen within the lab: darkish matter. You could recall that this darkish matter has been detected by observing its gravitational impression on seen matter. We’re pretty certain that about 85 per cent of the universe’s matter is that this invisible stuff, but to be defined by the usual mannequin.

Formulating a idea to elucidate darkish matter means hypothesising a brand new particle – or particles. A few of them might work together with present particles in methods which can be laborious to detect. The mechanism permitting these interactions is commonly often known as a mediator. Since mediators are additionally tough to detect, this sounds hopeless. However whereas we might by no means see a mediator straight, given the suitable circumstances, we are able to hope to see the particles they decay into – reminiscent of electron-positron pairs. That is the place B factories may help: they’re designed to isolate the merchandise of electron-positron collisions (the merchandise of matter and antimatter colliding).

As somebody exterior collider physics, I discover one of the attention-grabbing issues about this analysis is the way it retains experiments alive lengthy after they cease producing knowledge. For instance, the BaBar experiment on the SLAC Nationwide Accelerator Laboratory, close to Silicon Valley, was shut down in 2008, however researchers are nonetheless sifting by means of the info and utilizing it, together with to coach the subsequent technology of physicists.

In 2022, Brian Shuve at Harvey Mudd Faculty, close to Los Angeles, and an undergraduate crew examined a brand new thought towards nearly 20-year-old BaBar knowledge. I heard about this as a result of, amongst different issues, the thought proposes {that a} hypothetical particle known as the axion would act because the mediator between seen matter and darkish matter. Common readers might recall that my most important analysis is axions as darkish matter.

So do both of those situations (mine or Shuve’s) seize how our universe actually works? We could discover out as a part of the trouble to know the matter-antimatter asymmetry.