Griffiths Introduction to Elementary Particles · Problem 1.4

Elementary Particle Dynamics — David J. Griffiths

Physics — QFT · gell-mann-okubo-mass-formula-baryon-octet

Problem

The Gell-Mann/Okubo mass formula relates the masses of members of the baryon octet (ignoring small differences between

p

and

n

;

\Sigma^+

\Sigma^0

, and

\Sigma^-

; and

\Xi^0

and

\Xi^-

2(m_N + m_\Xi) = 3m_\Lambda + m_\Sigma

Using this formula, together with the known masses of the nucleon

N

(use the average of

p

and

n

\Sigma

(again, use the average), and

\Xi

(ditto), ``predict'' the mass of the

\Lambda

. How close do you come to the observed value?