Tuesday, July 21, 2015

Further evidence that 2 TeV bump could be MG,79 pion

For few days ago I told about 3.5 local sigma local evidence for a bump at about 2 TeV observed both at ATLAS and CMS. The title of the posting was "Pion of MG,79 hadron physics at LHC?". I learned about the bump from the posting of Lubos. Lubos was enthusiastic about left-right symmetric variant of the standard model as an explanation of the bump.

Lubos is five days later more enthusiastic about superstring inspired explanation of the bump . The title of the posting of Lubos is The 2 TeV LHC excess could prove string theory. The superstringy model involves as many as six superstring phenomenologists as chefs and the soup contains intersecting branes and anomalies as ingredients.

The article gives further valuable information about the bump also for those who are not terribly interested on intersecting branes and addition of new anomalous factors to the standard model gauge group. The following arguments show that the information is qualitatively consistent with the TGD based model.

  1. Bump is consistent with both ZZ, WZ, and according to Lubos also Zγ final states and is in the range 1.8-2.1 TeV. Therefore bump could involve both charged and neutral states. If the bump corresponds to neutral elementary particle such as new spin 1 boson Z' as proposed by superstring sextet, the challenge is to explain ZZ and Zγ bumps. WZ pairs cannot result from primary decays.

  2. There is dijet excess, which is roughly by a factor of 20 larger than weak boson excesses. This would suggest that some state decays to quarks or their excitations and the large value of QCD coupling strength gives rise to a the larger excess. This also explains also why no lepton excess is observed.

    For the superstring inspired model the large branching fraction to hadronic dijets suggesting the presence of strong interactions is a challenge: Lubos does not comment this problem. Also the absence of leptonic pairs is problematic and model builders deduce that Z' suffers syndrome known as lepto-phobia.

  3. Neutral and charged MG,79 pions can decay to virtual MG,79 or M89 quark pair annihilating further to a pair of weak bosons (also γγ pair is predicted) or by exchange of gluon to MG,79, M89 (or M107) quark pair producing eventually the dijet. This would explain the observations qualitatively. If the order of magnitude for the relative mass splitting between neutral and charged MG,79 pion is same as for ordinary pion one, the relative splitting is of order Δ M/M≈ 1/14 - less that 10 per cent meaning Δ M<.2 TeV. The range for the position of the bump is about .3 TeV.

  4. The predictions of TGD model are in principle calculable. The only free parameter is the MG,79 color coupling strength so that the model is easy to test.

For more details see the chapter New Particle Physics Predicted by TGD: part I of "p-Adic Length Scale Hypothesis" or the article What is the role of Gaussian Mersennes in TGD Universe?

For a summary of earlier postings see Links to the latest progress in TGD.


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