The latter seems to be the case for the model put forth by A. Crivellin, G. D'Ambrosio and J. Heeck a few days ago. In their preprint they not only point out how the large branching fraction of a Higgs boson into muon-tau pairs can be accounted for by a not-too-outlandish model; they also show how the CMS observation is "consistent" with two other deviations from the standard model, obtained by LHCb in the measurement of branching fractions of B mesons into K*μμ final state and in the ratio R between the rate of decays B->K*μμ over B->K*ee final states. So, let us look into this a bit more.

Of the 2.4σ H->μτ signal [see picture on the left for the various determinations in different final states, and their combination (red point on the bottom) which is away from the dashed line at zero -the SM prediction] I have extensively discussed in this blog earlier, so let me not do that here. I also discussed extensively the K*μμ anomaly in a post 1.5 years ago. The most recent anomaly, a 2.6σ effect (R. Aaij et al., Phys.Rev.Lett. 113,

151601 (2014), 1406.6482), is in the ratio of branching fractions mentioned above. This is measured experimentally by LHCb at

**R=0.745+0.090-0.074+-0.036**, while the SM predicts it to be essentially unity (1.0003+-0.0001).

It was pointed out in other papers how the R and the K*μμ anomaly may have the same non-SM origin.

The news is that the same origin could account for the anomalous Higgs decay of which CMS has a faint evidence. This entails invoking two-Higgs doublet models (2DHM), where instead of a single Higgs boson there are five physical states. 2DHMs are familiar to SUSY seekers, as all minimal SUSY theories require the same Higgs sector. However, 2DHM do not necessarily involve SUSY - they are more general. The added piece to explain the H->µt decays is a violation of symmetry between these two leptons. Authors note that such a violation is needed also to explain atmospheric neutrino mixing.

Further connections with tau lepton decay phenomenology are a bit harder to explain here, but find proper discussion in the article. However, they are very important, as e.g. the decay of tau leptons to three muons, mediated by a Z' boson, should occur in this model. As the branching fraction of that decay depends on the inverse square of the tan(beta) parameter of the 2DHM, one can connect a lower limit on the decay to the allowed region of tan(beta) of the model attempting to explain the quoted anomalies of CMS and LHCb. This makes the model interesting, as branching fractions of the order of one billionth will be probed in the future, allowing to test the model predictions.

I think I will stop here for now, as the details of this study are too technical for this blog (and I fear I would make wild misrepresentations if I tried to take my imperfect understanding of the matter and work out improbable simplifications). What I can say is that the H->mt effect will be put under the magnifying lens with the data that the LHC is going to start producing at 13 TeV in a few months... Just one more reason to be excited by 2015!

Interesting. I would not have guessed pairs of leptons differing by a generation. In my (evolving) idea one would expect that there are 10 particles in a generation. The four in the standard model have left and right handed, but the remaining six pair off with adjacent generation - and are related to 'boost' rather than rotation - even though boost is not a compact group. so they are not normal fermions, and thus anything that decays into them can not be a spin 1 boson. But they all should have color -so maybe they like to hang out with glueballs - maybe glueballs can decay into these things. Just to be specific - octonions have 480 multiplication tables and 'duality oscillators' . Divide by color * spin = 6 to get 80 'particles, for 20 in each of 4 families - half being antimatter.

There are 5 associations of 4 letters - but we can exchange the 'axial' and 'vector' subspaces to double

the number of particles. This should be like the u and d quarks.

Generation number is slot 0,1,2,3 for the letter (o)

leptons (ao)(bc)

quarks a(o(bc)) exchanging (bc) to (cb) flips the ordinary spin

dark1 (a(ob))c exchanging (ob) to (bo) changes the Generation - up one to the muon generation

dark2 a((ob)c) ditto

dark3 ((ao)b)c exchanging (ao) to (oa) drops the generation to slot 0 - maybe sort of like bosons ?

substitute txyz for oabc and you see that (ao) is like a boost. and (ab) is like rotation.

so the whole thing is determined by algebra. Not much room for fooling around.

so - if spin is the quantum analog of rotation, what is the quantum analog of boost ?

Also - if one can quantize energy and get 480 oscillators, by Heisenberg one should also 'quantize time'

or the 'quantum gravity analog of time'. Since muons look like ordinary particles, one might expect something

equally ordinary in quantizing spacetime - and the two ought to be related - like which particles dominate the universe - related to temperature.

sorry to bend your ear so much - but such flavor violation might not be so crazy after all. Now to look at your link.