The dimensions of elementary particles in quantum physics and string theory

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SUMMARY

In quantum physics, elementary particles are considered point-like and possess no dimensions, while string theory posits that these particles have one dimension. The distinction arises from the differing scales at which each theory operates, with string theory examining phenomena at a much smaller length scale. In supersymmetric theories, the mass dimension of the anticommutator of two supersymmetry generators (Q) is equal to the momentum (P), which has a mass dimension of 1, leading to a dimension of 1/2 for Q. This framework also establishes that scalar fields have a dimension of 1 and spinorial fields have a dimension of 3/2.

PREREQUISITES
  • Understanding of quantum physics principles
  • Familiarity with string theory concepts
  • Knowledge of supersymmetry and its implications
  • Basic grasp of mass dimensions in theoretical physics
NEXT STEPS
  • Research the implications of mass dimensions in quantum field theory
  • Explore the fundamentals of string theory and its dimensional framework
  • Study supersymmetry and its role in modern theoretical physics
  • Investigate the differences between quantum physics and string theory methodologies
USEFUL FOR

Physicists, theoretical researchers, and students interested in the foundational concepts of quantum physics and string theory, particularly those exploring the nature of elementary particles and their dimensions.

T=0
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I noticed that in quantum physics, an elementary particle has no dimensions, and is point like, but in string theory has one dimension. Why is this?
 
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T=0 said:
I noticed that in quantum physics, an elementary particle has no dimensions, and is point like, but in string theory has one dimension. Why is this?

This may sound silly, but basically it is because the theories are different. String theory is looking at things on a much smaller length scale than quantum theory.
 
Probably you mean "mass dimension"? In supersymmetric theories, the anticommutator of two susy generators Q is equal to the momentum P, which has mass dimension 1. From here, dimension of Q follows: it is 1/2. Similarly, by imposing that the action has 0 dim, you can find that a scalar field has dimension 1, a spinorial field 3/2, etc.
 
Thnx guys, great help.
 

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