Association between W Boson Decay and Leptons

[TDanskin]

As a physics A Level student, I am interested in understanding particle physics. Recently I have read that a W boson, as a relatively heavy particle, decays into one of three charged anti-leptons, and one of the three neutrinos. If a W boson decays to form an anti-tau lepton, it will also form a tau neutrino. Is the association of electrons, muons and tau particles with their 'corresponding' neutrinos purely based on this decay of W bosons?

 

[ohwilleke]

W bosons decay into every possible combination of particles that is permitted by the conservation laws.

 

[TDanskin]

Thanks so is the decay of a W boson not restricted to an anti-lepton and it's neutrino?

 

[Orodruin]

You can also decay into quarks.

If you decay into a (anti-)lepton, the produced neutrino is always of the same flavour. This is what defines neutrino flavour.

Edit: And by "you" I mean the W ...

 

[mfb]

The other option is quark plus antiquark.

Is the association of electrons, muons and tau particles with their 'corresponding' neutrinos purely based on this decay of W bosons?

Or via other process that involve real or virtual W bosons. In the Standard Model, those are the only interactions that convert elementary particles into other particles.

Edit: For clarification: particle+antiparticle -> something else is not meant here, that happens via other bosons as well.

 

[Orodruin]

The other option is quark plus antiquark.Or via other process that involve real or virtual W bosons. In the Standard Model, those are the only interactions that convert elementary particles into other particles.

I could have sworn Peskin-Schröder had an early example of electromagnetic $e^+e^-\rightarrow\mu^+\mu^-$ scattering ...
Anyway, I know what you mean, but an entry level student might not.

 

[ohwilleke]

The formula for W boson decays at the one loop level can be found here: https://en.wikipedia.org/wiki/W_and_Z_bosons#W_bosons_2

The experimentally measured values are as follows: http://pdglive.lbl.gov/Particle.action?node=S043

 

[TDanskin]

Thank you, this is all really useful :-)