Cross section-temperature equivalence

Click For Summary
SUMMARY

The discussion centers on the cross-section-temperature equivalence in particle interactions, specifically the equation Γm = nlσv, where nl represents the density of species l, σ is the interaction cross-section of species m, and v is the relative velocity between particles. The relation <σv> ∼ G²T², where G is Fermi's constant, is questioned for its general applicability, as it is derived under the assumption of weak interactions, which does not hold true for all particle types. Participants seek clarification on the origins and validity of this equivalence relation.

PREREQUISITES
  • Understanding of particle physics concepts, specifically interaction rates.
  • Familiarity with the definitions of cross-section and its significance in particle interactions.
  • Knowledge of Fermi's constant and its role in weak interactions.
  • Basic grasp of temperature's influence on particle behavior.
NEXT STEPS
  • Research the derivation of the cross-section in particle physics.
  • Study the implications of weak interactions in particle collisions.
  • Explore the relationship between temperature and particle interaction rates.
  • Investigate alternative models for interaction rates beyond weak interactions.
USEFUL FOR

Physicists, researchers in particle physics, and students studying interaction rates and cross-sections in high-energy physics.

karmion
Messages
1
Reaction score
0
It's assumed that interaction rate between a species of particule m and l is expressed as:

Γm=<nlσv>,

where nl is the density of the species l, σ the cross-section of species m (=probability of interaction) and v the relative velocity between the two particles.

It's also assumed that <σv>∼G²T², where G is fermi's constant.

I need to know where comes from this last equivalence relation, is there anyone that can help me please ?
 
Physics news on Phys.org
I don't know where this came from, but it is not true in general, as GF assumes a weak interaction, That's not true for particles in general.
 

Similar threads

High School What is the physical significance of mass-time-length equivalences in physics?
  • · Replies 8 ·
Replies
8
Views
3K
Undergrad Why is there such a difference between the total cross-section data? (simulation vs. experiment)
  • · Replies 1 ·
Replies
1
Views
825
Undergrad Absorption cross section of light in air
  • · Replies 3 ·
Replies
3
Views
3K
Graduate Scattering cross section between charged particle and magnetic moment
  • · Replies 1 ·
Replies
1
Views
1K
Graduate Why does the cross section for Dark Matter decrease with increasing mass?
  • · Replies 7 ·
Replies
7
Views
3K
Undergrad Understanding Nuclear Fusion Cross Section Diagrams
  • · Replies 2 ·
Replies
2
Views
3K
Graduate Equivalence equation between cross section & half life?
  • · Replies 6 ·
Replies
6
Views
2K
Graduate Cross section from subgraph in electron-proton DIS
  • · Replies 3 ·
Replies
3
Views
2K
Finding the scattering cross section
  • · Replies 2 ·
Replies
2
Views
2K
A cube of side L=2 m is made of a cooper cable with 2mm^2
  • · Replies 2 ·
Replies
2
Views
1K