Mathematical Principles of Theoretical Physics

(Rick Simeone) #1

4.3. UNIFIED FIELD MODEL BASED ON PID AND PRI 207


4.3.4 Potentials of the weak and strong forces


It is known that theU( 1 )gauge fields


(4.3.36) Aμ= (A 0 ,A 1 ,A 2 ,A 3 )


represent the electromagnetic potentials, with


(4.3.37)


A 0 =the Coulomb potential,
~A=magnetic potential, ~A= (A 1 ,A 2 ,A 3 ),

and the electric chargeeis


(4.3.38) e=theU( 1 )gauge coupling constant.


The electromagnetic forces are given by


(4.3.39)


Fe=−e∇A 0 the Coulomb force,
Fm=

e
c

~v×curl~A the Lorentz force.

Now, we consider theSU( 2 )andSU( 3 )gauge fields:

(4.3.40)


SU( 2 )gauge fields: Wμa= (W 0 a,W 1 a,W 2 a,W 3 a), 1 ≤a≤ 3 ,
SU( 3 )gauge fields: Skμ= (Sk 0 ,Sk 1 ,Sk 2 ,Sk 3 ), 1 ≤k≤ 8.

They areSU(N)tensors withN= 2 ,3, and haveN^2 −1 components. These components will
change under the transformation ofSU(N)generators. Thanks to PRI, theN^2 − 1 (N= 2 , 3 )
gauge fields in (4.3.40) can be combined into two vector fields as in (4.3.30):


(4.3.41)


Wμ=ωaWμa= (W 0 ,W 1 ,W 2 ,W 3 ),
Sμ=ρkSkμ= (S 0 ,S 1 ,S 2 ,S 3 ),

which have the same role as (4.3.36)-(4.3.39) for the electro-magneticU( 1 )gauge fields.
In the same spirit as the electromagnetic fields, for the two fields given by (4.3.41), we
have


(4.3.42)


W 0 =the weak force potential,
W~ =the weak magnetic potential, W~ = (W 1 ,W 2 ,W 3 ),

and


(4.3.43)


S 0 =the strong force potential,
~S=the strong magnetic potential, ~S= (S 1 ,S 2 ,S 3 ).

In addition, the weak and strong chargesgwandgsare


(4.3.44)


weak chargegw=SU( 2 )gauge coupling constant,
strong chargegs=SU( 3 )gauge coupling constant.
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