Science Record

33

@,= 1 + (6-2) a = 265p QE,Es + Ei + 9°) (8) = (62 + 1)(B,E2 + E,p? + 2p°E.) + (6 — 1mm. a

where E, and m, represent the energy and the mass of the *-meson respectively. If we let €,=1 and substitute the experimental value of E,, E, into (8), then we obtain #,=— 0.89, which agrees well with the experimental results». But this value is already quite near the upper limit of the expert

_ mental value.

We assume further that the decay is induced by the universal Fermi interaction of the V-A type"! and strong interactions involving #-mesons. If the renormalization effect is neglected, then the matrix determining the angular distribution has the same form as (8) with €&,=1. The asymmetry parameter a is then equal to — 0.89. However, if & #1 due to the renormalization effect, @ will change correspondingly. If g%/ge= 1.55, which is the ratio of that the spin of g% to g in B-decay phenomena, then

a= — 0.97 — 0.97, (9)

Hence, the accurate determination of the value of @ will be helpful to the investigation of the effect of the renormalization. Some experiments show that the spin of A particles might be 3/2. It is thus interesting to study the angular distribution of the decay products of a spin 3/2 particle. It is assumed that the A particle obeys the RaritaSchwinger equation with a spin 3/2. The following interaction Hamiltonian is introduced.

H® = GF (BCL + Ys) Dy Dp Yul + Ys) 2

+ Gyrull + 1s) DoF o(1s — 1b.) + OCF), (10)

where w, is a hyperon field which obeys the following equation and supplementary conditions:

(» = ap M)b. = 0,

Xy Yub. = 0,

o Ox.

Hal see) 35) 4 C11)

P= 0,

1) It came to the authors’ notice after the completion of this note that the same result has been pointed out by Marshak and Sudarshan,