Wednesday, June 29, 2005

Top quark mass, Higgs mass, and supersymmetry

The difficulties of both standard model and its minimal super-symmetric version are getting worse as the experimental data are getting more precise.

1. Situation in the standard model

The most recent situation in the standard model is discussed in the posting New Top Quark Mass? in Peter Woit's blog. Top quark mass is the source of problems. According to the posting, the latest combined CDF/D0 result is: mt = 174.3 +/- 3.4 GeV. The previous result using Run I data of mt = 178.0 +/- 4.3 GeV. In the standard model, the new top quark mass implies a value for the Higgs mass of 94 +54/-35 Gev. The problem is that a considerable portion of this range is excluded by the LEP result that the Higgs mass must be above 114 GeV.

2. Situation in the minimal super-symmetric version of standard model

The situation in the minimal super-symmetric version of the standard model (MSSM) discussed in the posting Fine-Tuned in Jacques Distler's blog is not brighter. MSSM predicts a relation between the masses of Z0, Higgs, top and stop. The lowest order prediction relates Z0 masses and is violated already now. Loop corrections predict that Higgs mass depends logarithmically on the mass ratio of top and stop. This can save the situation provided stop mass is high enough. The recent mass for top implies that stop mass must be above 850 GeV. This does not look natural. A further problem is that the quadratic term in Higgs potential contains a contribution which is proportional to the mass squared of stop so that the large value of stop mass forces fine tuning: the level of tuning is 1 per cent for the recent data.

3. Situation in TGD

Elementary particle physics bloggers do not seem to be too worried about the situation. Peter Woit sees this as a diplomatic gesture: why speak publicly about unpleasant things just when 100 years has passed from the miraculous year when Einstein published his articles revolutionizing the physics. Personally I would speak about a deep crisis. I hope that this could be forgiven: 27 years of total devotion has led a new beautiful theory eagerly waiting for the moment when the attitudes are ripe for it to replace the old and sick standard model. Since Peter Woit made it absolutely clear that the discussion about alternative scenarios replacing standard model and possibly allowing to understand elementary particles masses will not be tolerated in his blog, I can only make comments about the situation here.
  • p-adic thermodynamics for super-conformal algebra allows to understand elementary particle mass scales and also masses in one per cent precision. p-Adic mass calculations are discussed in the five chapters comprising the second part of p-Adic TGD. Number theoretical existence conditions, super-conformal symmetry, and p-adic length scale hypothesis fix the mass spectrum. Only the integers characterizing p-adic length scales of elementary particles remain free parameters but due to the exponential sensitivity of the p-adic mass scale to the value of this integer, the choices are highly unique and comes from the freedom to choose CKM matrix. CKM matrix can be fixed by number theoretical constraints by using minimal input (Cabibbo angle and CP breaking parameter).
  • The basic deviation from the standard model is that the dominating contribution to fermion masses comes from p-adic thermodynamics rather than from the coupling to Higgs. Hence the coupling of Higgs to fermions can be much weaker than in standard model. Hence the rate for Higgs production can be by a factor 1/100 slower than predicted by standard model. This could explain why Higgs has not been detected if it exists. The question whether TGD really predicts Higgs is not yet settled. Group theoretical considerations favor its existence and one can imagine a candidate for Higgs.
  • The model predicts the existence of p-adically scaled up versions of elementary particles. The real surprise was that these scaled up variants allow to replace Gell-Mann mass formula for the masses of low lying hadrons. The model explains some forgotten anomalies such as Aleph anomaly and suggests that the strange bumps in the measured mass distribution of top quark correspond to the scaled up variants of lighter quarks.
  • TGD predicts super-conformal invariance but this symmetry does not imply space-time super-symmetry. The generators of global super-symmetries generated by covariantly constant right handed neutrino simply vanish identically. Super-conformal symmetries are genuine symmetries but change particle masses. The new exotic particles correspond to colored excitations and do not give rise to long range forces.
  • TGD suggests also the existence of a scaled up variant of hadron physics corresponding to Mersenne prime M89 characterizing also intermediate gauge boson. The mysterious Centauro events appearing above cosmic ray energies of about 106 GeV provide support for M89 hadron physics.
    • Centauros are estimated to involve a production of a "fireball" of mass of 180+/- 60 GeV. By a direct scaling the mass of the proton of M89 physics would be 481 GeV and one might wonder whether the fireball could result in the collision of a relativistic M89 baryon with an ordinary nucleon inducing M89--> M107 phase transition producing extremely dense phase of ordinary quark-gluon matter decaying via "color glass condensate" to ordinary hadrons.
    • Color glass condensate would correspond to a state of conformally confined quarks and gluons Bose-Einstein condensed at highly tangled color magnetic string in Hagedorn temperature. This condensate would represent a particular instance of dark matter behaving in many respects like blackhole but which Planck length replaced with hadronic length scale. The evaporation this hadronic blackhole would predict isotropic spectrum for the decay products consistent with the experimental findings. The photons emitted from the system would be BE condensates of "dark photons" decaying to ordinary photons: this could explain why photons expected from the decays of neutral pions are not detected. The formation of a hadronic black hole explains also the puzzling RHIC findings discussed previously in this blog.
Empathic reader probably guesses that sometimes I must feel myself quite frustrated while wittnessing the deepening crisis in theoretical particle physics. hep-th has become a symbol of the situation. In ancient times it contained preprints about high energy particle physics, nowadays it contains only M-theory stuff having nothing to do with elementary particle physics or physics of any other kind. The fact that the discussion about alternatives is openly discouraged and censored does not make me feel better.


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