# If Electrons and Muons had the same mass will we know that there are two particles?

1. Mar 10, 2012

### alemsalem

they are in two different generations, but they would behave in the exact same way.
maybe we can tell from neutrinos?

Thanks!

2. Mar 10, 2012

Re: If Electrons and Muons had the same mass will we know that there are two particle

Most obvious analogy I can think of is the three quark colours. There's no experiment we can do that can tell us the actual colour of any specific quark at any given time. And yet, we were able to infer the existence of colours - ie there being three different types of each quark flavour - from experimental evidence such as that (a) without this additional quantum number, baryons would be symmetric in the interchange of any two quarks, in contravention of the Pauli principle, and (b) the branching ratios of reactions such as e+e- → hadrons would be three times too large as compared to those into eg muons.

Last edited: Mar 10, 2012
3. Mar 11, 2012

### Bill_K

Re: If Electrons and Muons had the same mass will we know that there are two particle

Yes, this is the point. Universality of the weak interactions requires that the weak current is made up of equal parts from eνe, μνμ, etc. If e and μ could not otherwise be distinguished, the additional factor of two in the amplitude of any reaction that produced these particles would call our attention to the fact that there was two of them.

4. Mar 11, 2012

### alemsalem

Re: If Electrons and Muons had the same mass will we know that there are two particle

Thanks,, so for example beta decay would be happening at twice the rate?
is the extra factor of two compared to theory or other decays?

5. Mar 12, 2012

### arivero

Re: If Electrons and Muons had the same mass will we know that there are two particle

And of course, if it is a lighter mass, such as the one of the electron, you could consider chemistry.

6. Mar 12, 2012

### alemsalem

Re: If Electrons and Muons had the same mass will we know that there are two particle

cool! it would also change the periodic table if we had two "electrons".

Last edited: Mar 12, 2012