PHYSICS

QUANTUM FIELD THEORY: PART 2

The law of entropy holds the supreme position among the laws of the universe.If your pet theory is found to contradict the second law I can give you no hope,there is nothing for it but to collapse in deep humiliation(Sir Arthur Stanley eddington)

Spin,Chirality bosons and fermions

There is a difference in the waves of bosons and fermions. The bosonic wave is a circle with same face always on outside. The fermions wave has the face twisted on itself. As a result the boson wave travels always on the same face but a fermion wave travels alternatively on inside and outside faces.A consequence of this is that boson waves reinforces the phase while fermion waves cancel each other if overlapping.A boson wave also  has integer number of wave turns or spins while fermionic waves have half integer turns or spins

A fermion wave may have two types of chirality or face twisting. They are right handed and left handed and represents two ways the twisting can be done. This results in two types of fermions, left and right handed.

  The left and right handed fermions are separate particles and they cannot be converted to each other by SU2 gauge interaction.

Particle families

The fermions can be divided into families based on their interactions. How particles interact has undergone profound change during early evolution of the universe when Higgs particles first appeared.All fermions can undergo U1 interactions based on phase change with each other before symmetry breaking.The magnitude of U1 interactions is however dependent on weak hypercharge of the particles which are different for right and left handed particles(-1 for left handed electrons and -2for right handed electrons)So before symmetry breaking U1 interactions distinguished between left and right handed fermions. However fermions are grouped into pairs which only can change faces among themselves after SU2 interaction. These families are electron and neutrino family,up and down quark family,charm strange quark family and up down quark family.Only left handed fermions have families of particles that can change faces. The right handed particles cannot do so.

Particles in same family have same hypercharge .The two components have opposite weak isospin . Thus the left handed neutrino and electron have identical weak hypercharge of -1 but opposite weak isospin of +1/2 and -1/2.There is no right handed neutrino in nature. The right handed up and down quarks have non identical hypercharge +4/3 and -2/3 . So they cannot change faces and have weak isospin of 0.

All fermions and bosons before symmetry breaking were massless.

Higgs field and symmetry breaking

Higgs field is a scalar field and has a uniform value in the universe. If a particle couples to a Higgs field it experiences a resistance to its wave oscillations. The Higgs field before symmetry breaking existed at a very high temperature. As the universe expanded and temperatures became less the Higgs field fell to a zero potential. However its is a peculiarity of Higgs field that at minimum potential the field strength is not zero. It is like a spring that has to be pushed down to keep it at zero amplitude. 

   The Higgs field gives mass to all fermions by changing the chirality. Thus a right handed electron will change into a left handed electron a million times a second due to the Higgs field. This constant change in chirality is gives mass to fermions.

    Another principal effect is on the three bosons of weak interaction W1,W2, and W3 and the mediator of U1 interaction called B boson. The Higgs boson acts to combine W3 and B boson according to the ratio Z0 is W3+B and photon is W3-B. As a result photon acquires a charge :isospin charge +hypercharge/2.It now mediates U1 interaction instead of charge of original B boson. As a result both left handed and right handed electrons acquire same charge of -1  and interact identically. Thus U1 interaction after symmetry breaking treats all interactions equally.This is according to the formula charge=Y/2(-1/2)+Iz (-1/2) for left handed electron and for right handed electrons charge= Y/2(-2/2) +Iz(0/2)Also now neutrinos acquire a 0 charge and cannot interact with photon.

CPT symmetry of origin of matter

SU2 symmetry operations do not apply to right handed fermions and this is not changed by Higgs symmetry breaking. Also though SU2 transformation occurs with left handed electrons it does not occur with left handed positron ,that is when charge is reversed. However there is a transformation called parity change. Here the chirality of the fermion changes and the wave also rotates by 180degree. This restores the mirror image of fermionic wave. If parity transformation is combined by charge reversal  then each cancels other and SU2 transformation occurs with right handed positrons.

     So during of birth our universe a assymetry in action of weak force has occurred and this is because both charge conjugation and parity transformation has got separated. However CP symmmetry violations have been detected . If time is reversed these violations do not occur. Thus time moving positively has contributed to excess matter over antimatter  

Ack: Particles,fields and forces

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