Meson (thing)

A meson is a particle that consists of a quark and an antiquark. Mesons form a subset of hadrons

The following is a (growing) list of mesons. If you spot an error, feel free to /msg me. If you want to add some, /msg me too, rather than creating a new writeup.

Notes:

• All rest masses are in MeV/c².
• "Makeup" refers to the constituent quarks (u=up, d=down, s=strange, c=charm, t=top, b=bottom).
• An underlined symbol denotes an antiparticle, which is normally written with a bar over the symbol.

Pion Positive (π⁺)
Makeup: ud
Rest Mass: 139.6
Charge: +1
Common Decay Modes: π⁺ -> μ⁺ + ν_μ

Pion Zero (π⁰)
Makeup: (uu+dd)/√2
Rest Mass: 135.0
Charge: 0
Common Decay Modes: π⁰ -> 2γ

Pion Negative (π^-)
Makeup: ud
Rest Mass: 139.6
Charge: -1
Common Decay Modes: π^- -> μ^- + ν_μ

Kaon Positive (K⁺)
Makeup: us
Rest Mass: 493.7
Charge: +1
Common Decay Modes: K⁺ -> μ⁺ + ν_μ, K⁺ -> π⁺ + π⁰

Kaon Negative (K^-)
Makeup: us
Rest Mass: 493.7
Charge: -1
Common Decay Modes: K^- -> μ^- + ν_μ, K^- -> π^- + π⁰

Kaon Zero Short (K⁰_S)
Makeup: (symmetric mix of ds and ds)
Rest Mass: 497.7
Charge: 0
Common Decay Modes: K⁰_S -> π⁺ + π^-, K⁰_S -> 2π⁰
(this meson is weird - someone should do a good writeup in Kaon about it)

Kaon Zero Long (K⁰_L)
Makeup: (antisymmetric mix of ds and ds)
Rest Mass: 497.7
Charge: 0
Common Decay Modes: K⁰_L -> π⁺ + e^- + ν_e
(this meson is weird - someone should do a good writeup in Kaon about it)

Eta Zero (η⁰)
Makeup: (uu + dd - 2ss)/√6
Rest Mass: 548.8
Charge: 0
Common Decay Modes: η⁰ -> 2γ, η⁰ -> 3μ
(this meson is weird - someone should do a good writeup in Eta about it)

Rho Positive (ρ⁺)
Makeup: ud
Rest Mass: 770
Charge: +1
Common Decay Modes: ρ⁺ -> π⁺
(this meson is considered to be an "excited" pion - the spins of the consituent quarks are "aligned")

Rho Negative (ρ^-)
Makeup: ud
Rest Mass: 770
Charge: -1
Common Decay Modes: ρ^- -> π^-
(this meson is considered to be an "excited" pion - the spins of the consituent quarks are "aligned")

Phi (Φ)
Makeup: ss
Rest Mass: 1020
Charge: 0
Common Decay Modes: Φ -> K⁺ + K^-, Φ -> K⁰ + K⁰

D Positive (D⁺)
Makeup: cd
Rest Mass: 1869.4
Charge: +1
Common Decay Modes: D⁺ -> K + ?, D⁺ -> e + ?

D Zero (D⁰)
Makeup: cu
Rest Mass: 1864.6
Charge: 0
Common Decay Modes: D⁰ -> K + ?, D⁰ -> μ + ?, D⁰ -> e + ?

D Negative (D⁺)
Makeup: cd
Rest Mass: 1869.4
Charge: -1
Common Decay Modes: D^- -> K + ?, D^- -> e + ?

D Positive Strange (D⁺_S)
Makeup: cs
Rest Mass: 1969
Charge: +1
Common Decay Modes: D⁺_S -> K + ?

D Negative Strange (D^-_S)
Makeup: cs
Rest Mass: 1969
Charge: -1
Common Decay Modes: D^-_S -> K + ?

J/Psi (J/Ψ)
Makeup: cc
Rest Mass: 3096.9
Charge: 0
Common Decay Modes: J/Ψ -> e⁺ + e^-, J/Ψ -> μ⁺ + μ^-, J/Ψ -> τ⁺ + τ^-

B Positive (B⁺)
Makeup: ub
Rest Mass: 5279
Charge: +1
Common Decay Modes: B⁺ -> D⁰ + ?

B Zero (B⁰)
Makeup: db
Rest Mass: 5279
Charge: 0
Common Decay Modes: B⁰ -> D⁰ + ?

B Negative (B^-)
Makeup: ub
Rest Mass: 5279
Charge: -1
Common Decay Modes: B^- -> D⁰ + ?

Upsilon (Y)
Makeup: bb
Rest Mass: 9460.4
Charge: 0
Common Decay Modes: Y -> -> e⁺ + e^-, Y -> μ⁺ + μ^-, Y -> τ⁺ + τ^-