Anti-matter

[HappyCoder]

I have a few questions about anti-matter that I was hoping some of you could answer.

 

First of all what processes do we know about that create generate anti-matter and what circumstances create better conditions for the anti-matter to be generated. And what particles does that include? I have heard about electron/positron pair production but what about proton/anti-proton?

 

Secondly I have heard about a hypothises about neutron/anti-neutron occilation where a neutron can become an anti-neutron and vise versa. What is the standing of this theory?

[swansont]

You can create antimatter in decay reactions (beta decay) and with photons and in particle collisions where you have enough energy to convert to mass and create particle/antiparticle pairs. e+e- requires 1.02 MeV of energy, while p+p- requires about 1878 MeV.

[insane_alien]

the neutron/antineutron thing wouldn'twork as it is not an elementary particle for one. it is composed of quarks so you would need three quarks occilating together. and if it can happen in a neutron then why not a proton, meson or other quark composed particle.

[Farsight]

First of all what processes do we know about that create generate anti-matter and what circumstances create better conditions for the anti-matter to be generated. And what particles does that include? I have heard about electron/positron pair production but what about proton/anti-proton?

Antiprotons are created routinely. Hang on, I'll find a link. Here's one: http://agni.phys.iit.edu/~vpa/fnalantiproton.html.

 

Secondly I have heard about a hypothises about neutron/anti-neutron occilation where a neutron can become an anti-neutron and vise versa.

No.

 

What is the standing of this theory?

Zip. No way can a neutron oscillate into an anti-neutron. A Bs meson does it no problem and can be explained in quite simple terms. But not a neutron. No way.

[Ti]

Hey you suppose anti-matter does not have mass? Then we could time travel? what about our bodies? I'm getting quite fat to travel at c.

[Klaynos]

It does have mass (well the same mass properties as matter does).

[Ti]

So it is subjected to gravity? What is the purpose of finding it then?

[Klaynos]

Yes. We've already found it. What do you mean what's the point? To enhance our understanding of the universe...

[ellipsis]

One possible theory that explains the dominance of matter over antimatter is that neutrino is an anti-particle of itself, so that two neutrinos will annihilate, while the other two survive. How COULD that be possible? Won't the other two also annihiate? I'm so confused...

[Klaynos]

One possible theory that explains the dominance of matter over antimatter is that neutrino is an anti-particle of itself, so that two neutrinos will annihilate, while the other two survive. How COULD that be possible? Won't the other two also annihiate? I'm so confused...

 

It is required that neutrinos and anti-neutrinos are distinct particles, there is eveidence of this from detection methods that will only detect neutrinos or anti-neutrinos. As for the rest of your post it doesn't seem to make much sense... Which two will annihillate, and survive? Can you explain that more clearly?

[antimatter]

Cosmic Rays also produce particle pairs

[ellipsis]

SORRY! I didn't explain it...

I can't quite remember it, but it says that a neutron, in some process, emits a neutrino and an anti-neutrino. If neutrino is an antiparticle of itself, then when two neutrons emit two pairs, one neutrino will immediately annihilate one neutrino, thus leaving us with two neutrinos.

So what are the current theories explaining why there is more matter than anti-matter?

[Klaynos]

SORRY! I didn't explain it...

I can't quite remember it, but it says that a neutron, in some process, emits a neutrino and an anti-neutrino. If neutrino is an antiparticle of itself, then when two neutrons emit two pairs, one neutrino will immediately annihilate one neutrino, thus leaving us with two neutrinos.

 

This is not something I've come across but particle physics is not my best area.

 

So what are the current theories explaining why there is more matter than anti-matter?

 

We don't know, there's lots of hypothesises....