introduction-weak-interaction-volume-one

where A and B are the initial and final hadrons in the reaction respectively ,
receives contributions from JPG = 0 + states, of the form 5,r, 7-a- . The 5„
resonance with the lowest mass is probably S(970), although this may in fac t
be a bound state of the I = 1 KC system and not the pion system (18) .
gA (g2 ) (5 .4 .17 )
receives contributions from JPG = 1 + states, such as 3-rr and 5 rc , or, in
terms of particles, AI (1100) .
(gA (g 2 ) ( mA + m B) + q2 fA(4 2 ) ) (5 .4 .18 )
is dependent upon 0-- states such as the pion .
(h A (g2 ) ) (5 .4 .19 )
receives contributions from 1 1-1- states of the form 41 , 6ry , such a s
B (1235) . For the 13Y( . 1, the situation is similar, except that the contributin g
resonant states are all of the form K n77, and thus have a strangeness of 1 .
For (5 .4 .14) and (5 .4 .15) the corresponding strange resonance is (1420) ;
for (5 .4 .16) probably K(725) ; for (5 .4 .17) K1 (1320) ; for (5 .4 .18) the kaon ;
and for (5 .4 .19) probablyKA ' (1230) . Weak form factors may roughly b e
interpreted as measures of the spatial distribution of the 'weak charge' of
particles, or of the characteristics leading them to behave in certain way s
in weak interactions .
5 .5 Weak Kagnetism .
current term in
We know that, when free from strong interaction effects, the vecto r
the beta decay matrix element i s
V = u Y u
r p r n
and the axial vector current term i s
(5 .5 .1 )
Ar = up Y r Y 5 un (5 .5 .2 )
If,
however, we reintroduce strong effects, we hav e
V r = up (fV Yr – gV d rs
q s – hv qr ) un , (5 .5 .3 )
and
Ar = up (fA r — gA rs q s — hA qr ) Y5 un . (5 .5 .4 )
where