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

Do you know that, in physics, now we have magnificence factories? This has nothing to do with artwork or glamour. As a substitute, 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 manufactured from quarks, the subatomic particles discovered inside peculiar 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, attraction or unusual quark.

This make-up offers B mesons an especially brief existence, far faraway from each 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’s extra matter than antimatter.

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

Mesons are fascinating as a result of they exist between matter that’s ample within the universe and antimatter, which isn’t. As such, we might be able to exploit them to study extra in regards to the asymmetry between matter and antimatter. Understanding this is able to clarify why there’s 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 complicated when you think about that mesons even have their very own antimatter counterparts. Every B antimeson is manufactured from a magnificence quark and an up, down, attraction or unusual antiquark. Within the case of B mesons made with unusual or down quarks (referred to as the impartial as a result of they haven’t 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 are 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 will look to see whether or not the oscillations are precisely half and half. Are the particles we first make within the collisions extra more likely 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 may 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 affect 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 principle 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 are laborious to detect. The mechanism permitting these interactions is commonly referred to as a mediator. Since mediators are additionally tough to detect, this sounds hopeless. However whereas we might by no means see a mediator immediately, given the suitable circumstances, we will hope to see the particles they decay into – resembling 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 some of the fascinating 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 information and utilizing it, together with to teach the subsequent technology of physicists.

In 2022, Brian Shuve at Harvey Mudd Faculty, close to Los Angeles, and an undergraduate workforce examined a brand new thought in opposition to nearly 20-year-old BaBar knowledge. I heard about this as a result of, amongst different issues, the concept 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 eventualities (mine or Shuve’s) seize how our universe actually works? We may discover out as a part of the hassle to know the matter-antimatter asymmetry.