Z Bosons to Lepton Pairs: Why Equal for All?

  • Thread starter Thread starter DuckAmuck
  • Start date Start date
  • Tags Tags
    Lepton
DuckAmuck
Messages
238
Reaction score
40
Hi guys,
Quick question:
Why is the branching ratio of Z bosons into a lepton-antilepton pair equal for all leptons?
Is it not dependent on mass?
Thanks
DA
 
Physics news on Phys.org
The Z coupling to leptons is universal. The Z is much heavier than even the heaviest leptons, so phase space effects are tiny.
 

Thread 'Toponium Discovered'

Toponium is a hadron which is the bound state of a valance top quark and a valance antitop quark. Oversimplified presentations often state that top quarks don't form hadrons, because they decay to bottom quarks extremely rapidly after they are created, leaving no time to form a hadron. And, the vast majority of the time, this is true. But, the lifetime of a top quark is only an average lifetime. Sometimes it decays faster and sometimes it decays slower. In the highly improbable case that...
View full post »

Thread 'Dirac-Delta from Normalization of Continuous Eigenfunctions'

I'm following this paper by Kitaev on SL(2,R) representations and I'm having a problem in the normalization of the continuous eigenfunctions (eqs. (67)-(70)), which satisfy \langle f_s | f_{s'} \rangle = \int_{0}^{1} \frac{2}{(1-u)^2} f_s(u)^* f_{s'}(u) \, du. \tag{67} The singular contribution of the integral arises at the endpoint u=1 of the integral, and in the limit u \to 1, the function f_s(u) takes on the form f_s(u) \approx a_s (1-u)^{1/2 + i s} + a_s^* (1-u)^{1/2 - i s}. \tag{70}...
View full post »

Similar threads

A Current theories on the lepton masses?
Replies
26
Views
2K
I LHC To Announce Its Lepton Universality Violation Results On Tuesday (20-Dec)
Replies
30
Views
3K
I What is the electric charge of a neutrino?
Replies
6
Views
2K
I Why Can a W Boson Decay into Quarks of Different Generations?
Replies
1
Views
3K
Why don't a charm-anticharm meson decay to pair of leptons?
Replies
29
Views
6K
I Suppression of semileptonic lambda decays
Replies
1
Views
1K
A Higgs boson and its decay width
Replies
7
Views
3K
I New Constraints On The Higgs Boson Width
Replies
11
Views
3K
Can symmetries in GUTs explain the occurrence of FCNCs in particle interactions?
Replies
10
Views
2K
I How powerful would a collider have to be to observe a sphaleron?
Replies
2
Views
3K

Hot Threads

Recent Insights

Back
Top