﻿ G-parity
Fri . 20 Jul 2020
TR | RU | UK | KK | BE |

# G-parity

g-parity and rho decays, g parity
In theoretical physics, G-parity is a multiplicative quantum number that results from the generalization of C-parity to multiplets of particles

C-parity applies only to neutral systems; in the pion triplet, only π0 has C-parity On the other hand, strong interaction does not see electrical charge, so it cannot distinguish amongst π+, π0 and π− We can generalize the C-parity so it applies to all charge states of a given multiplet:

G π + π 0 π − = η G π + π 0 π − }\pi ^\\\pi ^\\\pi ^\end}=\eta _\pi ^\\\pi ^\\\pi ^\end}}

where ηG = ±1 are the eigenvalues of G-parity The G-parity operator is defined as

G = C e i π I 2 }=}\,e^}}

where C }} is the C-parity operator, and I2 is the operator associated with the 2nd component of the isospin "vector" G-parity is a combination of charge conjugation and a π rad 180° rotation around the 2nd axis of isospin space Given that charge conjugation and isospin are preserved by strong interactions, so is G Weak and electromagnetic interactions, though, are not invariant under G-parity

Since G-parity is applied on a whole multiplet, charge conjugation has to see the multiplet as a neutral entity Thus, only multiplets with an average charge of 0 will be eigenstates of G, that is

Q ¯ = B ¯ = Y ¯ = 0 }=}=}=0}

see Q, B, Y

In general

η G = η C − 1 I =\eta _\,-1^}

where ηC is a C-parity eigenvalue, and I is the isospin For fermion-antifermion systems, we have

η G = − 1 S + L + I =-1^\,}

where S is the total spin, L the total orbital angular momentum quantum number For boson–antiboson systems we have

η G = − 1 L + I =-1^\,}

• Quark model

## References

• T D Lee and C N Yang 1956 "Charge conjugation, a new quantum number G, and selection rules concerning a nucleon-antinucleon system" Il Nuovo Cimento 3 4: 749–753 Bibcode:1956NCim3749L doi:101007/BF02744530
• Charles Goebel 1956 "Selection Rules for NN̅ Annihilation" Phys Rev 103 1: 258–261 Bibcode:1956PhRv103258G doi:101103/PhysRev103258

g parity, g-parity and rho decays • G-parity beatiful post thanks!

29.10.2014

G-parity
G-parity
G-parity viewing the topic.

### Timeline beyond October following the September 11 attacks

The following list contains certain dates beyond October 2001 involving the September 11 attacks ...

### Smash Hits

Smash Hits was a pop music magazine, aimed at teenagers and young adults and originally published in...

### 2014–15 USC Trojans women's basketball team

The 2014–15 USC Trojans women's basketball team will represent University of Southern California dur...