Griffiths Introduction to Elementary Particles · Problem 4.25

Bound States — David J. Griffiths

Physics — QFT · gell-mann-nishijima-quarks

Problem

(a) Check that the Gell-Mann–Nishijima formula works for the quarks

u

d

, and

s

. (b) What are the appropriate isospin assignments,

|I\, I_3\rangle

, for the antiquarks,

\bar{u}

\bar{d}

, and

\bar{s}

? Check that your assignment is consistent with the Gell-Mann–Nishijima formula. [Since

Q

I_3

A

, and

S

all add, when we combine quarks together, it follows that the Gell-Mann–Nishijima formula holds for all hadrons made out of

u

d

s

\bar{u}

\bar{d}

, and

\bar{s}