Robert Mann - An Introduction to Particle Physics and the Standard Model · Problem 5.3

Accelerators — Robert Mann

Physics — Particle Physics · angular-momentum-decay-distributions

Problem

\Lambda

-particles are produced by a pion beam in the reaction

\pi^- + p \to K^0 + \Lambda

and are observed via their decay

\Lambda \to \pi^- + p

. You are an experimentalist trying to determine the total spin

s(\Lambda)

of the

\Lambda

. The angle of the decay products relative to the beam axis is

\theta

. (a) If the

\Lambda

is produced exactly along the beam axis what are the possible values of

s_z(\Lambda)

? (b) A trustworthy theorist tells you that

s(\Lambda)

can't be larger than 3. Given this constraint, what are the possible angular decay distributions for the forward-produced

\Lambda

's as a function of their spin?