Wednesday, March 08, 2023

Does a Higgs-like particle decaying to electron-muon pairs exist?

It is a long time since I have written anything about particle physics for years. Now the LHC collaboration at CERN has represented evidence for the anomaly. Sabine Hossenfelder talks about the anomaly in popular terms in a Youtube video (see this). There is also a preprint about the anomaly (see this). The evidence is 2.5 sigmas (standard deviation) so that the anomaly is much below the minimum of 5 sigma for a discovery and could quite well disappear.

What has been studied is the possible occurrence of lepton flavor violating decays of Higgs bosons in proton-proton collisions at cm energy of 13 TeV has been analyzed using data from 2016-2018 period. The integrated luminosity is 136 fb-1.

A small anomaly has been observed. It could be due to the flavor violating decay H→ e+/- μ-/+ of Higgs having mass 125 GeV. eμ pair could also come from the decay of a new boson, call it X, with mass assumed to be the range 110-160 GeV.

The dominant production modes for the Higgs boson are gluon fusion (ggH) and vector boson fusion (VBF). In both modes the interesting final state oppositely charged eμ pair. It would appear as a peak at mass m(H) or m(X) on top of a smoothly falling background due to the purely leptonic decays of tt* and WW events, plus Drell-Yan events with a misidentified lepton. Monte Carlo fit indicates a 2.5 sigma bump 146 GeV.

Could TGD explain this anomaly? The TGD (see this) based topological explanation of the family replication phenomenon indeed predicts new exotic bosons (see this, this, and this).

  1. Fundamental fermions would in TGD framework correspond to partonic 2-surfaces, whose orbits define light-like 3-surfaces identifiable ad boundaries between Minkowskian and Euclidean space-time regions. The Euclidean regions correspond to deformations of what I call CP2 type extremals. Orientable 2-surfaces are characterized by the genus g defined as the number of handles attached to a 2-sphere to obtain the topology in question.
  2. TGD predicts that 3 lowest genera are special in the sense that they allow global Z2 symmetry as a conformal symmetry unlike higher generations (see this). This raises the 3 lowest genera in a special position. The handles behave like particles and the higher genera would not form bound states of handles and have a mass continuum characteristic for free many-particle states unlike the lowest ones corresponding to g=0,1,2. This boils down to the assumption that only 2 handles can form a bound state.
  3. The fundamental fermion would correspond to a partonic 2-surface carrying a point-like fermion and would serve as building bricks of both fermions as bosons as elementary particles. Elementary particles would correspond to closed monopole flux tube structures connecting two Euclidean wormhole contacts so that the monopole flux loop would run along the first Minkowskian space-time sheet and return along the other.
Group theoretically, the 3 fermion generations behave like an SU(3)g triplet, completely analogous to the (u,d,s) triplet introduced by Gell-Mann. This combinatorial symmetry could define an approximate dynamical symmetry involving SU(3)g→ U(2)g symmetry breaking, analogous to that in the case of Gell-Mann's SU(3).
  1. Each electroweak gauge boson and gluon would form an SU(3)g octet analogous to (π,K,η) and SU(3)g singlet analogous to η'.
  2. Ordinary gauge bosons would SU(3)g singlets analogous to η'. Their couplings to fermion families would be identical and thus obey fermion universality. These states would be superpositions of pairs with g=0,1,2.
  3. Besides this, 2 additional SU(3)states with vanishing SU(3)g quantum number analogous to π0 and η are predicted. Their couplings to fermions induce a violation of fermion universality coming from the coupling to both gluons and weak bosons.

    There are some indications for this violation from the earlier experiments (see this) and the p-adic mass scales of the higher boson families as analogs of π0 and η correspond to p-adic length scales assignable to Mersennes or Gaussian Mersennes. The couplings of these states to fermionic loops imply deviations from the predictions of the standard model and might explain the reported anomalies.

    Here one would have a deviation from the expectations suggested by the analogy with the Gell-Mann's SU(3), which would suggest that the ordinary weak bosons are more massive than the exotic ones: this would not be the case.

  4. Also non-diagonal bosons with non-vanishing SU(3)g quantum numbers, being analogous to π+/- and 2 kaon doublets, are predicted. I have earlier assumed (see this) that these states are much more massive than the SU(3)g neutral states.

    If one takes the recent finding at the face value, the situation would not be this. The analogy with the Gell-Mann's SU(3) suggests that one has a weakly broken U(1)×U(1)⊂ U(2)g ⊂ SU(3)g symmetry such that the two lowest generations correspond to u and d. Both gluons and electroweak gauge bosons, including Higgs, would have additional states decaying to oppositely charged eμ pairs and thus violate lepton universality. Also counterparts of kaons as pairs involving g=2 partonic 2-surfaces are predicted.

  5. The simplest interpretation for X would be in terms of a Higgs like states analogous to π+/-. The U(2)g symmetry would be violated if the mass of X is 146 GeV: one would have Δ m/< m>= 2(m(X)-m(H))/(m(X)+m(H) ≈ 15 %.
This picture raises questions related to the CKM mixing as mixing topologies of partonic 2-surfaces (see this).
  1. It is assumed to be due to topology changing time evolution for partonic 2-surfaces: a kind of dispersion in the "world of classical worlds'' (see this), or more precisely, in the moduli space of conformal equivalences of 2-surfaces consisting of Teichmüller spaces for various genera, would be in question.
  2. Could the exchanges of SU(3)g octet bosons between both fermions and bosons induce the mixing dynamically or at least contribute to the mixing. This mixing is not a single particle phenomenon. It conserves SU(3)g "isospin" and "hypercharge" and essentially this means conservation of total genus as sum of signed genera, which are opposite for fermions and antifermions. If SU(3)g octet has masses above M89 mass scale assignable to Higgs, this mixing is expected to be rather small and an effect comparable to weak interactions.
  3. The mass scale of SU(3)g photon octet must be large, say M89 mass scale: otherwise one would lose approximate conservation of various lepton numbers and a bad failure of the Universality. Color confinement would allow a light SU(3)g gluon octet. What implications could the additional light gluons have?
See the article About the TGD based views of family replication phenomenon and color confinement or the chapter with the same title.

For a summary of earlier postings see Latest progress in TGD.

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