Why must the mediator of the strong force be heavy?

  • Context: Undergrad 
  • Thread starter Thread starter Phys12
  • Start date Start date
  • Tags Tags
    Force Strong force
Click For Summary
SUMMARY

The discussion centers on the necessity of a heavy mediator for the strong force, as proposed by Yukawa. A massless mediator would result in a Coulomb potential, indicating a long-range force, while a massive mediator leads to a Yukawa potential, characterized by a negative exponential that suppresses the potential with increasing mass, thus resulting in a shorter range. The strong force is mediated by massless gluons, but due to confinement, only colorless states are observable at lower energies, preventing a Coulomb-like behavior.

PREREQUISITES
  • Understanding of Yukawa potential and its implications
  • Familiarity with the concept of massless and massive mediators
  • Knowledge of gluons and their role in the strong force
  • Basic grasp of confinement in quantum chromodynamics (QCD)
NEXT STEPS
  • Study the Yukawa potential in detail, focusing on its mathematical formulation
  • Explore the concept of confinement in quantum chromodynamics (QCD)
  • Review Griffith's Introduction to Elementary Particles, specifically Problem 1.2
  • Investigate the role of gluons in mediating the strong force and their properties
USEFUL FOR

Students of particle physics, theoretical physicists, and anyone interested in the fundamental forces of nature and their mediators.

Phys12
Messages
351
Reaction score
42
I'm reading Griffith's Introduction to Elementary Particles and it says that when Yukawa proposed his theory of the strong force, it was an indication that the meadiator of that force must be a heavy particle since the force is a short ranged force. Why is that the case? I cannot get the intuition behind it
 
Physics news on Phys.org
A massless mediator leads to a Coulomb potential - it has a long range. A massive mediator leads to a Yukawa potential, where larger masses lead to shorter ranges.
 
  • Like
Likes   Reactions: Phys12
Look at the (negative!) exponential in the yukawa potential. It surpresses the potential if the mass of the mediator gets larger.
 
Also note that this is the residual strong force mediated by pions. The strong force itself is mediated by massless gluons. The reason that this does not lead to a Coulomb potential is confinement, i.e., that only colourless states exist at lower energies.
 
  • Like
Likes   Reactions: Phys12
Phys12 said:
Why is that the case?

You know how right after he writes that, Griffiths says "See Problem 1.2"? You should see problem 1.2.
 

Similar threads

Undergrad Why the binding energy per nucleon has specific pattern?
  • · Replies 2 ·
Replies
2
Views
2K
Undergrad Strong and Weak Nuclear forces at long ranges
  • · Replies 2 ·
Replies
2
Views
2K
High School The Strong Nuclear Force: Is my understanding correct?
  • · Replies 14 ·
Replies
14
Views
4K
Undergrad Separation energy of nucleons and Coulomb barrier
  • · Replies 1 ·
Replies
1
Views
2K
Graduate My Confusion Regarding the Strong Force
  • · Replies 6 ·
Replies
6
Views
2K
Undergrad How Does Beta Decay Relate to the Role of W Bosons in Weak Nuclear Force?
  • · Replies 4 ·
Replies
4
Views
4K
Graduate Why must strong force theory be QCD?
  • · Replies 26 ·
Replies
26
Views
7K
Graduate What Are the Missing Links in Enrico Fermi's Beta-Decay Theory?
  • · Replies 4 ·
Replies
4
Views
2K
Graduate Do all exchange bosons violate energy conservation?
  • · Replies 2 ·
Replies
2
Views
2K
Graduate Why Do Physicists Postulate the Existence of a Graviton?
  • · Replies 6 ·
Replies
6
Views
3K