- #1
venus_in_furs
- 19
- 1
Hello
In sphaleron interactions (B - L) is conserved.
So we need an antilepton excess (provided by decay of heavy RH neutrinos in leptogenesis).
This is then converted to a baryon excess, via sphalerons, to explain the baryon excess that we observe.
But the conversion factor is ~1/3.
For example in this paper https://arxiv.org/abs/hep-ph/0502082 (Equation 17, where a_sph = 1/3 )
I first interpreted this as saying only 1/3 of antilepton doublets are converted, meaning we are left with 2/3.. and I was wondering what happens to this 'left over' excess.
Now I am thinking about it again, I think that sounds a bit stupid.
Does it actually just mean that it takes three antilepton doublets to convert to one baryon?
(and so we convert all antilepton excess to baryons).
I guess 1/3 is because baryons have three quarks? although, actually, it is not exactly 1/3 it is approximate, so maybe it is for another reason?
Also... do we not need a mechanism to generate a lepton asymmetry of the universe?
For example, I presume the universe has more electrons than positrons? How did this occur?
Thanks
In sphaleron interactions (B - L) is conserved.
So we need an antilepton excess (provided by decay of heavy RH neutrinos in leptogenesis).
This is then converted to a baryon excess, via sphalerons, to explain the baryon excess that we observe.
But the conversion factor is ~1/3.
For example in this paper https://arxiv.org/abs/hep-ph/0502082 (Equation 17, where a_sph = 1/3 )
I first interpreted this as saying only 1/3 of antilepton doublets are converted, meaning we are left with 2/3.. and I was wondering what happens to this 'left over' excess.
Now I am thinking about it again, I think that sounds a bit stupid.
Does it actually just mean that it takes three antilepton doublets to convert to one baryon?
(and so we convert all antilepton excess to baryons).
I guess 1/3 is because baryons have three quarks? although, actually, it is not exactly 1/3 it is approximate, so maybe it is for another reason?
Also... do we not need a mechanism to generate a lepton asymmetry of the universe?
For example, I presume the universe has more electrons than positrons? How did this occur?
Thanks