Friday, July 16, 2021

Serendipitous sum rules

Today I shall report that I am rather more positive than I was, about the second "wrong" idea in the previous post. The reason is that the sum of all the masses in a multiplet, is a quite natural item to appear in a sum rule! So the relation would be, that the sum of the masses of the charged leptons, considered as a multiplet of a flavor or family symmetry, equals the sum of the neutron and proton masses, with the neutron and proton to be considered as an isospin doublet. 

What I still lack is a mechanism. I believe that (for example, in the linear sigma model), nucleon mass can be regarded as originating in the spontaneous breaking of chiral symmetry. Meanwhile, the Higgs-yukawa interactions in the standard model give the fermions their masses, once electroweak symmetry breaking occurs; so one might consider models in which chiral symmetry breaking triggers electroweak symmetry breaking (something which might also explain the order-of-magnitude similarity between the QCD scale and the Fermi scale). 

On the other hand, since the variations among the fermion masses derive from the yukawas, it might seem that the relevant symmetry-to-be-broken is the family symmetry, not the electroweak symmetry... Then there are other hints, like obtaining electroweak symmetry by gauging part of chiral symmetry (something which is formally common in chiral perturbation theory, I think), and the Rivero idea that the leptons are Goldstone fermions, superpartners of mesons. 

In other news, I will mention that tweeted out a fictitious paper whose content is serendipitously close to other things I have been thinking about. The very first posts on this blog were discussions of snarxiv papers, and if there was nothing else to blog about, I might have talked more about "Special Lagrangian Branes Wrapped on the Moduli Space of Squashed Lens Spaces". But I'll save that for another time. 

Sunday, June 27, 2021

Ideas, right and wrong

There are many things that I could or should post about here. I must mention the terrible news of Marni Sheppeard's death, which is a loss in so many ways. I blog about her when I can. 

There is also a backlog of ideas, waiting to be analysed and sorted. Today I just wanted to mention two lines of thought. 

One is the potential harmony between Rivero's sBootstrap, Dienes's misaligned supersymmetry, and the Veltman-like sum rule of Lopez-Castro - Pestieau - Garces Doz. 

The other is a cluster of thoughts about how to explain the 313 MeV scale in Brannen's version of the Koide formula. The main thought is: maybe it's a kind of Goldberger-Treiman relation. I think that thought is promising. 

Then there are some other thoughts about it which are surely wrong, but which I shall mention here. One is: what if the charged leptons are different forms of a mesino with a rest mass of 626 MeV, undergoing relativistic periodic motion in compact extra dimensions. You may ask: that's alright for the tauon, but what about the electron and muon, whose mass is less than that? Well, the "answer" is that they have imaginary momentum in the extra dimensions, and that overall there are three complex extra dimensions, like a Calabi-Yau... There's no way this is true, but it was too cute to not mention. 

My other wrong thought is this: If you take the trace of Brannen's mass matrix, you find that the sum of electron, muon, and tauon masses, equals two times a nucleon mass. But what if it's really a proton mass plus a neutron mass - the two members of the nucleon isospin doublet? Again, I think it's a cute idea, but it seems very unlikely that this is where the factor of 2 comes from.