If we define the electron as an antiparticle, will there be a problem?

[darkdark10]

Now we have a particle-antiparticle asymmetry problem.

But, if we define electron and neutrino as antiparticle, will there be a problem?

Original formula

Modified formula

Original formula

Modified formula

If the classification of electron and neutrino is changed to antiparticles, the particle-antiparticle asymmetry problem can be solved.
Is there any reason why this should not be done?

 

[ohwilleke]

Now we have a particle-antiparticle asymmetry problem.

But, if we define electron and neutrino as antiparticle, will there be a problem?

Original formula
View attachment 350898

Modified formula

View attachment 350899


Original formula
View attachment 350900

Modified formula
View attachment 350901

If the classification of electron and neutrino is changed to antiparticles, the particle-antiparticle asymmetry problem can be solved.
Is there any reason why this should not be done?

While what we call particles and what we call antiparticles is arbitrary, the terms have to be used in either the way that we do now, or exactly the opposite way.

Under this proposal e⁺ and e^- would both be particles and couldn't annihilate. This is known to be contrary to what happens when we collide e⁺ and e^-.

Therefore, this proposal is wrong.

 

[Orodruin]

Under this proposal e+ and e- would both be particles and couldn't annihilate

No, he wants to switch both. Positron is a particle and electron an antiparticle.

There is no a priori problem writing the standard model lagrangian with the CP conjugate of the lepton fields instead of the fields themselves.

The real question though is why the OP thinks this would solve the matter-antimatter asymmetry?

 

[mfb]

It removes matter particles and adds antimatter particles, getting the difference closer to zero with that definition. You still need a process that converts leptons to baryons and does that asymmetric for matter and antimatter, leaving matter baryons and antimatter leptons with the changed definition. Ultimately it's still the same problem, just phrased differently. But we know baryons can be converted to (standard definition) antileptons and antibaryons can be converted to leptons, so flipping the definition of the leptons has some motivation. Won't happen because the current definition is well-established, however.

 

[Vanadium 50]

A sad feature of PF is that there are some people who are very prolific, but don't know what they are talking about, Unfortunately, they can spout nonsense faster than it can be corrected.

It is true that whether we use the words "matter" or "antimatter" is arbitrary - we could call in "snersh" and "glorbitross" if we wanted to. There is no information there. But in the mathematical structure of the theory you have u's, v's, ubars and vbars, and these are not arbitrary. The asymmetry is entirely real, no matter which words we use to describe it.

 

[Orodruin]

It removes matter particles and adds antimatter particles, getting the difference closer to zero with that definition.

The point of what is many times called matter-antimatter asymmetry in popular sources is not really that. It is a baryon asymmetry. This does not change at all redefining the electron as an antiparticle.

If you consider all particles and antiparticles, it actually makes things worse, not better. Sphalerons in the early Universe violate B+L while conserving B-L. For sphaleron equilibrium, B and L will have opposite sign, meaning that if you switch what is lepton and antilepton, they will have the same sign and B+L will be conserved. You would end up with a B+L that is larger than the B+L we have within the current definition.

In a charge neutral universe, there are essentially as many electrons as protons. But neither of these are the only contributions to B or L, respectively. This essentially means the negative L number has to be largely hidden away in the neutrino sector.

 

[Vanadium 50]

It is a baryon asymmetry. This does not change at all redefining the electron as an antiparticle.

But it does if you redefine neutrons as 10 antiparticles!

 

[Orodruin]

But it does if you redefine neutrons as 10 antiparticles!

Then you destroy the relevant conservation laws … not just change them …

 

[mfb]

In a charge neutral universe, there are essentially as many electrons as protons. But neither of these are the only contributions to B or L, respectively. This essentially means the negative L number has to be largely hidden away in the neutrino sector.

What large negative number? After BBN we are left with n protons, n electrons, n/7 neutrons, and neutrinos.

Currently all the protons, electrons and neutrons are counted as matter. The sphaleron process can produce matter both in the baryon and lepton sector by producing baryons and removing antileptons, or producing leptons and removing antibaryons.

Swapping leptons, the protons and electrons cancel each other and we are only left with neutrons and neutrinos for net matter. The sphaleron process cannot produce net matter any more because it conserves B+L' with the new lepton definition. It can still produce a baryon and lepton asymmetry. That one doesn't change of course.

I'm not OP, but the conversion process between baryons and antileptons is one argument to invert the definition.

 

[ohwilleke]

No, he wants to switch both. Positron is a particle and electron an antiparticle.

I must have misread his post. Never mind.

 

[DaTario]

It seems to me that if you have much more green pencils than red ones, this situation (asymmetry) will be preserved if you decide to redefine the color green as red and red as green.