Why QCD

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Why QCD

• A single theory responsible for phenomena
  ranging from distance scales of
• the order 10-19m to scales of the order
  104m.

• and it is all determined by essentially only a
  single parameter.

• It builds from objects that to not exist in a
  common sense.

• quarks and gluons are permanently confined.

• Predicts existence of matter made from
  radiation or hybrid matter.

• It is the only fundamental theory that for
  most parts is not amendable
• to standard techniques

It is far from being solved
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.. and the reasons are

• relativistic, quantum, many-body system
• (local quantum field theory)

• unphysical degrees of freedom
• (gauge symmetry)

• cannot be rigorously defined before it is solved
  
• (renormalization)

• the interaction is strong
• (confinement)

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Relativistic (Lorentz) boosts mix individual
components
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Self similarity and renormalization
In QCD gg(a) (interaction strength) also
satisfies a R.G.E
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Adiabatic potential
r
r0 0.5 fm
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There are different stories
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Story 2 (Feynman)
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Show structure function
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MESSAGE DORMULATE PROBLEM DEPENDING ON THE
QUESTION
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Stort 2 fore gluons
Show structure function