So basically they came up with the answer and are now trying to prove the working out?
That’s how theoretical Physics works, and how a lot of science is done. Look for a pattern, come up with an idea, predict stuff based on your idea for a pattern, then try and do an experiment to prove it.
Problem is, you don’t really know if your pattern idea’s not the right one or your experiment just didn’t work.
Antimatter does it exists, its no different to normal matter, it just has the opposite electrical charge.
Well, not exactly. Antimatter is the exact opposite of matter in all respects.
Think about your bank account. You can have money, you can have no money, and you can have anti-money aka an overdraft. An overdraft is the exact opposite of a positive balance. You spend more, it gets bigger rather than smaller. You can trade debt, or swap IOUs, it works just like real money. If you get otherwise identical positive and negative balances together, you end up with nothing at all. You and I could start off with two empty bank accounts, I give you £100, then you have £100 and I have -£100.
The problem is that we see much more matter in the universe than antimatter. Which, since the universe was created form nothing, seems a bit counter-intuitive.