Explain GIM & FCNCs: Quark Gen, Cabbibo Suppression

  • Context: Graduate 
  • Thread starter Thread starter aw7879
  • Start date Start date
  • Tags Tags
    Mechanism
Click For Summary
SUMMARY

The discussion centers on the relationship between quark generations and flavor-changing neutral currents (FCNCs) in the context of the Standard Model (SM) of particle physics. It is established that FCNCs do not occur at tree level due to the absence of non-diagonal interactions in the Higgs sector and the Z and A sectors, with flavor changes only possible through charged currents mediated by W bosons. The argument against tree-level FCNCs was historically significant in predicting the existence of the charm quark, reinforcing the concept that flavor changes cannot occur without charge involvement.

PREREQUISITES
  • Understanding of quark generations in particle physics
  • Familiarity with flavor-changing neutral currents (FCNCs)
  • Knowledge of the Standard Model (SM) interactions
  • Basic concepts of the Cabibbo angle and CKM matrix
NEXT STEPS
  • Research the implications of the Cabibbo suppression in particle interactions
  • Study the role of the CKM matrix in quark flavor transitions
  • Explore the historical context of charm quark discovery and its relation to FCNCs
  • Examine the differences between charged and neutral current interactions in the SM
USEFUL FOR

Particle physicists, students of theoretical physics, and anyone interested in the intricacies of quark interactions and the Standard Model.

aw7879
Messages
5
Reaction score
0
Can Anyone explain how the existence of more than one generation of quark means that flavour change neutral currents do not occour at tree level? How is a flavour changing neutral current deffined anyway? I understand that it has something to do with Cabbibo suppression
 
Physics news on Phys.org
FCNC is that you can change flavour with a neutral boson, there are no nondiagonal interactions in the higgs sector and the Z and A sector of the SM, only non diagonal (CKM) in the W+/W- sector.

"how the existence of more than one generation of quark means that flavour change neutral currents do not occour at tree level?"

is not true, can you show where you find it?
 
It is my understanding that this argument of no flavour changing neutral currents at tree level was used to predict the existence of the charm quark. The rule basically states that there cannot be a change in flavour whilst the charge current is neutral.

http://en.wikipedia.org/wiki/Flavor_changing_neutral_current
 

Similar threads

Undergrad New Naming Rules for Exotic Hadrons at the LHC: LHCb Collaboration Paper (2022)
  • · Replies 7 ·
Replies
7
Views
2K
High School How many gluons on average are there in a proton at once?
  • · Replies 9 ·
Replies
9
Views
3K
Undergrad How powerful would a collider have to be to observe a sphaleron?
  • · Replies 2 ·
Replies
2
Views
3K
Graduate Higgs mechanism and relativity
  • · Replies 6 ·
Replies
6
Views
3K
Graduate Majorly confused over the cabibbo matrix?
  • · Replies 2 ·
Replies
2
Views
4K
Graduate Recent papers on particle masses
  • · Replies 2 ·
Replies
2
Views
2K
Graduate SU(5), 'Standard Model decomposition', direct sum etc.
  • · Replies 23 ·
Replies
23
Views
5K
High School Preon quark models excluded by LHC
  • · Replies 7 ·
Replies
7
Views
3K
Undergrad B -> s µµ decays: Current status
  • · Replies 49 ·
2
Replies
49
Views
12K
Graduate Are Quantum Mechanics Interpretations Misrepresented in Fiction?
  • · Replies 1 ·
Replies
1
Views
2K