Link between CP violation and supersymmetry?

Click For Summary

Discussion Overview

The discussion centers on the relationship between CP violation in B meson decays and implications for supersymmetry (SUSY). Participants explore the significance of branching fractions and how they relate to the viability of SUSY models in light of experimental observations.

Discussion Character

  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant notes that CP violation in B mesons, particularly in the decay to two muons, raises concerns about SUSY, seeking clarification on this connection.
  • Another participant argues that the decay of Bs mesons to two muons is not directly related to CP violation, suggesting that new particles could enhance the branching fraction significantly.
  • A participant requests clarification on the term "branching fraction," leading to an explanation that it refers to the probability of a particle decaying into a specific final state, with specific statistics provided for Bs and Bd mesons.
  • Further discussion highlights that SUSY could introduce additional decay channels, potentially increasing the predicted branching ratios, which could conflict with experimental results if they do not match observed rates.

Areas of Agreement / Disagreement

Participants express differing views on the relationship between CP violation and SUSY, with some asserting a connection while others contest this notion. The discussion remains unresolved regarding the implications of branching ratios for SUSY models.

Contextual Notes

Participants mention various parameters that could influence SUSY predictions, indicating that the discussion is contingent on specific model assumptions and experimental outcomes.

epsilon
Messages
29
Reaction score
1
I have been looking in SUSY and have seen that the CP violation of B mesons into two muons is one of the key facts that has cast further doubt over SUSY. I don t really understand how the CP violation of B mesons is a sign of SUSY issues, so if you are able to clear this up for me that would be much appreciated.
 
Physics news on Phys.org
I think you mean the decay of Bs mesons to two muons. This has nothing to do with CP violation. The standard model prediction for the branching fraction is tiny, but new fields/particles could have enhanced that significantly as they could add new decay mechanisms.
 
Yes that's what I mean, forgot to include the subscript. Could you explain what you mean by the branching fraction?
 
The probability that the particle decays to two muons. On average, about 3 out of a billion Bs decay to two muons.

For Bd, the probability is even lower with 1 out of 10 billions.
 
As for susy issues, I'd say that the main concern about the branching ratios come from the fact that SuSy will allow additional channels for a process...
So let's say that for the SM you have X% predicted events...
and for SM+SUSY you have X+Y % predicted events...
If experiment allows for X% but not for X+Y% then SUSY [models] gets disfavored. Of course you have a lot of parameters to play with in such scenarios, like playing with the masses of the spartners and so on... But the more you play with it, SuSy can change a lot..
 
Last edited:

Similar threads

Replies
1
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 4 ·
Replies
4
Views
3K
  • · Replies 13 ·
Replies
13
Views
4K
  • · Replies 10 ·
Replies
10
Views
6K
  • · Replies 2 ·
Replies
2
Views
3K
  • · Replies 31 ·
2
Replies
31
Views
4K
  • · Replies 2 ·
Replies
2
Views
4K
  • · Replies 5 ·
Replies
5
Views
2K
  • · Replies 0 ·
Replies
0
Views
3K