introduction-weak-interaction-volume-one

measuring the value of the coefficient a (3 .5 .13c) for pure decays . In a
pure Fermi decay ,
a = (I GV I 2 - jGSl2)/(IGVl2 + 1GSI2)
(3 . 6 .3a )
where
IGil2 = 4(Gil2 +
Experiments yield (42 )
ICl2) .
(3 .6 .3b )
a = 0 .97 ± 0 .14 ,
(3 .6 .3c)
definitely favouring a vector coupling. Experiments on the pure Camow -
Teller proces s
6 He > 6 Li e + v (3 .6 .4a )
imply (42, 43 )
a (IGT l 2 - I GA I 2 )/3(IG T I 2 I CA l 2 )
_ - 0 .3343 t 0 .0030 , (3 .6 .4b )
suggesting an axial vector interaction in Gamow-Teller transitions . For some
years,
6 He e-v angular correlation experiments tended to favour the S T
combination, but a critical analysis of these results (44) demonstrate d
that the experiments were, in fact, inconclusive .
There have been basically three attempts to predict the V- A
structure of the weak interaction theoretically (45) . The first method
was suggested by Marshak and Sudarshan (46) in 1958 . We define the so-calle d
'chirality' transformatio n
V( x) ----> y(x) = Y 5 45(x) . (3 .6 .5 )
However, the Dirac equation yield s
Y r ( a /axr)lf = - mil, (3.6 .6 )
and thus we obtain
Yr ( a / 3xr) (T 5 4r)
-Y5 (r r ( a / axr)V) = m (Y 5v )
(3.6 .7 )
Combining the equations (4 .6 .6) and (4 .6 .7) we may now writ e
rr (a /d xr ) Vt = m i~1 3 (3 .6 .8a )
where