Up+Down Scalar Meson: Isospin SU(3) & Low Energies

  • Context: Graduate 
  • Thread starter Thread starter ddimensoes
  • Start date Start date
  • Tags Tags
    Meson Scalar
Click For Summary
SUMMARY

The discussion centers on the absence of mesons composed solely of up and down quarks at low energies, despite the existence of axial (pseudoscalar) mesons like pions. Participants explore the implications of almost-unbroken isospin SU(3) symmetry and the mixing of particles, which prevents the formation of "flavour-pure" mesons at lower energy levels. It is established that mesons consist of a quark and an antiquark, and the color charge must sum to neutral, ruling out two-quark particles.

PREREQUISITES
  • Understanding of meson classification, particularly axial and pseudoscalar mesons.
  • Knowledge of isospin SU(3) symmetry and its implications in particle physics.
  • Familiarity with quark-antiquark pairings and color charge conservation.
  • Basic concepts of particle mixing and its effects on meson states.
NEXT STEPS
  • Research the properties and classifications of mesons, focusing on axial and pseudoscalar types.
  • Study the principles of isospin SU(3) symmetry and its role in particle interactions.
  • Examine the phenomenon of particle mixing and its impact on quark-antiquark states.
  • Explore higher-energy meson production and the characteristics of "flavour-pure" mesons.
USEFUL FOR

Particle physicists, students of quantum mechanics, and researchers interested in meson properties and quark interactions.

ddimensoes
Messages
3
Reaction score
0
Why is there no meson made up by only up and down quarks but even under parity? Is there something that forbids its existence?
The pions are all axial (pseudoscalar) mesons. As we go higher in energy, there are such "flavour-pure" mesons. Is this a consequence of the almost-unbroken isospin SU(3)? If this is so, why can't I find such "flavour-pure" mesons at low energies?
 
Physics news on Phys.org
All mesons are made up of quark plus antiquark. You can't have a two quark particle since the color charge must add up to white.

I can't comment on the rest of your question - beyond my expertise.
 
Particles mix, and the closer they are in mass, the more they mix. So you don't have a pure uubar or ddbar state because they mix, and the eta adds some ssbar, etc. The same thing happens with the scalars.
 

Similar threads

Undergrad New Naming Rules for Exotic Hadrons at the LHC: LHCb Collaboration Paper (2022)
  • · Replies 7 ·
Replies
7
Views
2K
Graduate Eta prime meson as SU(3) singlet
  • · Replies 8 ·
Replies
8
Views
6K
Graduate The "electroweak eta meson"
  • · Replies 8 ·
Replies
8
Views
2K
Graduate New ideas on confinement and meson masses from Brazil
  • · Replies 4 ·
Replies
4
Views
3K
Undergrad Imagining a Higgsless Universe
  • · Replies 35 ·
2
Replies
35
Views
9K
Undergrad Why do we need two representations of SU(3)
  • · Replies 8 ·
Replies
8
Views
2K
Undergrad SU(3) quark model and singlet states
  • · Replies 7 ·
Replies
7
Views
4K
Undergrad Understanding Weak Isospin in SU(2) Gauge Theory
  • · Replies 6 ·
Replies
6
Views
5K
Graduate Chiral symmetry breaking and approximate flavour symmetry
  • · Replies 8 ·
Replies
8
Views
6K
Undergrad What would a hypothetical quark-quark collision yield?
  • · Replies 4 ·
Replies
4
Views
3K