Naked Science Forum

Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: CPT ArkAngel on 10/12/2010 01:41:22

Title: Have antiquarks been observed?
Post by: CPT ArkAngel on 10/12/2010 01:41:22
Have antiquarks been observed?

Quarks have a very short life. How do they end their life?
Title: Re: Have antiquarks been observed?
Post by: QuantumClue on 10/12/2010 02:53:21
Aren't quarks there own antiparticles...

I might be wrong, but for some reason I was under the suspicion.
Title: Re: Have antiquarks been observed?
Post by: CPT ArkAngel on 10/12/2010 03:44:35
No, they are supposed to have corresponding antiparticles.

http://en.wikipedia.org/wiki/List_of_particles
Title: Have antiquarks been observed?
Post by: JP on 10/12/2010 05:53:42
Yes.  Remember that "observation" of very short-lived particles in particle physics is usually done by looking for signatures that they've decayed into longer-lived particles.  Antiquarks decay into what are known as jets, which are big showers of particles that can be easily seen by particle detectors.  The properties of the jet allows you to figure out what it came from, which is how antiquarks are observed.
Title: Have antiquarks been observed?
Post by: Pikaia on 10/12/2010 08:27:07
Recently atoms of anti-hydrogen have been produced, with anti-protons as their nuclei, and anti-protons are made of anti-quarks.

Anti-quarks are destroyed when they meet normal quarks, in the same way that positrons (anti-electrons) are destroyed when they meet electrons.

Anti-up and anti-down quarks are normally stable, like up and down quarks, but other quarks and anti-quarks are unstable and decay spontaneously.
Title: Have antiquarks been observed?
Post by: JP on 10/12/2010 09:53:00
Recently atoms of anti-hydrogen have been produced, with anti-protons as their nuclei, and anti-protons are made of anti-quarks.

Anti-quarks are destroyed when they meet normal quarks, in the same way that positrons (anti-electrons) are destroyed when they meet electrons.

Anti-up and anti-down quarks are normally stable, like up and down quarks, but other quarks and anti-quarks are unstable and decay spontaneously.

Yeah--I'd also add that although they're stable, up and down quarks can't exist for very long without forming larger particles like protons and neutrons.  That's why you still need to detect these other particle jets rather than the original quarks.
Title: Have antiquarks been observed?
Post by: Soul Surfer on 10/12/2010 22:55:27
Antiquarks are very common in reactions at energies and timescales where quark effects can be observed.  All mesons are quark-antiquark pairs.
Title: Have antiquarks been observed?
Post by: CPT ArkAngel on 11/12/2010 05:15:56
In an accelerator, after the collision and separation of a proton in to quarks, what happened to a quark that doesn't find other quarks to form another particle? Does it continue to live or end in gamma rays or...?
Title: Have antiquarks been observed?
Post by: JP on 11/12/2010 06:29:23
Separating a quark from its friends requires a lot of energy.  As I understand it, when they get far apart, this energy causes other quarks to spontaneously form out of the vacuum (and soak up some of the energy) to partner with it.
Title: Have antiquarks been observed?
Post by: CPT ArkAngel on 11/12/2010 17:30:19
This is strange. Maybe energy from dark matter particles...
Title: Have antiquarks been observed?
Post by: CPT ArkAngel on 12/12/2010 03:35:17
Do they have traces of gamma rays on the target or do they have some way to see them?
Title: Have antiquarks been observed?
Post by: JP on 12/12/2010 04:38:10
This is strange. Maybe energy from dark matter particles...

No.  It's energy from the field that holds quarks together.  Unlike gravity or electromagnetism, which gets weaker as you pull objects apart, the strong force that holds quarks together doesn't and that force is what provides the energy here.

Do they have traces of gamma rays on the target or do they have some way to see them?
They do have ways of detecting gamma rays.
Title: Have antiquarks been observed?
Post by: QuantumClue on 12/12/2010 23:10:04
No, they are supposed to have corresponding antiparticles.

http://en.wikipedia.org/wiki/List_of_particles


Yes your absolutely right. I was getting confused with material I was reading earlier on.