ω meson
Omega meson (ω) |
|
---|---|
classification | |
Boson Hadron Meson |
|
properties | |
electric charge | neutral |
Resting energy | (782.65 ± 0.12) MeV |
Spin parity | 1 - |
Isospin | 0 |
average lifespan | 7.75 ± 0.07 × 10 −23 s |
Decay width | (8.49 ± 0.08) MeV |
Quark composition |
Antisymmetric superposition of Up - Anti-Up and Down - Anti-Down |
The ω meson , also omega meson , is a meson that has spin 1 (vector meson ), is made up of up and down quarks , but does not belong to the ρ mesons . While ρ mesons namely balanced flavor - wave functions have ( isospin 1), the flavor wave function of the ω-meson antisymmetric (isospin 0).
description
The ω meson is in the singlet representation of the SU (2) flavor. This means that there is only one ω meson with the flavor wave function
- .
The ω meson is therefore often referred to as an isoscalar particle, i.e. a scalar with isospin symmetry (isospin I = 0). Therefore the ω-meson cannot be regarded as the excitation of a pion (I = 1).
89% of the ω meson decays into three pions via the strong interaction and 8% via the electromagnetic interaction into a pion and a photon .
Experimental measurements
The ω meson has been proven in experiments since the 1960s.
See also
Individual evidence
- ↑ The information on the particle properties (info box) are, unless otherwise stated, taken from: J. Beringer et al. ( Particle Data Group ): 2013 Review of Particle Physics. In: Physical Review D . Vol. 86, 2012, 010001 and 2013 partial update for the 2014 edition. Particle Data Group, accessed May 22, 2018 .
- ↑ N. Nakamura et al . (2010): Particle listings - ω (PDF; 182 kB)
- ↑ R. Kraemer, L.Madansky, Mosley sea, et al : Meson Resonance production in the π + d interactions at 1:23 BeV / c . In: Phys. Rev. B . No. 136 , 1964, pp. 496-506 , doi : 10.1103 / PhysRev.136.B496 .