Monday, January 24, 2011

Second top quark related anomaly from CDF

Both Jester and Lubos tell about top quark related anomaly in proton-antiproton collisions at Tevatron reported by CDF collaboration. The anomaly has been actually reported already last summer but has gone un-noticed. For more detailed data see this.

What has been found is that the production rate for jet pairs with jet mass around 170 GeV, which happens to correspond to top quark mass, the production cross section is about 3 times higher higher than QCD simulations predict. 3.44 sigma deviation is in question meaning that its probability is same as for the normalized random variable x/σ to be larger than 3.44 for Gaussian distribution


Recall that 5 sigma is regarded as so unprobable fluctuation that one speaks about discovery. If top pairs are produced by some new particle, this deviation should be seen also when second top decays leptonically meaning a large missing energy of neutrino. There is however a slight deficit rather than excess of these events.

One can consider three interpretations.

  1. The effect is a statistical fluke. But why just at the top quark mass?

  2. The hadronic signal is real but there is a downwards fluctuation reducing the number of leptonic events slightly from the expected one. In the leptonic sector the measurement resolution is poorer so that this interpretation looks reasonable. In this case the decay of some exotic boson to top quark pair could explain the signal. Below this option will be considered in more detail in TGD framework and the nice thing is that it can be connected to another top quark related anomaly reported by CDF for few weeks ago.

  3. Both effects are real and the signal is due to R-parity violating 3-particle decays of gluinos with mass near to top quark mass. This is the explanation proposed in the paper of Perez and collaborators.

    This option could make sense also in TGD framework where R-parity is violated by the same -purely TGD based- mechanism which forces massivation of particles at the fundamental level. Super partners are created by adding covariantly constant right-handed neutrinos and antineutrinos to the states. The dynamics of the modified Dirac equation however mixes right-handed and left-handed neutrinos so that R-parity is not conserved.

    Addition: The three-body decay would be in TGD framework sg→ st+tbar (or t+stbar) → t+tbar+ νbar (or t+tbar+ ν). Only the other member of top pair would produce neutrino and the charged lepton accompanying it in electroweak decays would be absent so that the signature is unique. t is accompanied by νRbar and tbar by νR and gluino by νRbar at fermionic wormhole throat or by νR at antifermionic wormhole throat also gluino for which both throats are sfermionic is possible.

    The three-body decay would be in TGD framework sg→ st+tbar (or t+stbar) → t+tbar+ νbar (or t+tbar+ ν). Only the other member of top pair would produce neutrino and the charged lepton accompanying it in electroweak decays would be absent so that the signature is unique. t is accompanied by νRbar and tbar by νR and gluino by νRbar at fermionic wormhole throat or by νR at antifermionic wormhole throat also gluino for which both throats are sfermionic is possible.

    This effect is one of the basic signatures of quantum TGD and due to the fact that gamma matrices appearing in Dirac equation are different from those appearing in standard quantum field theories. Both induced gamma matrices (defined as projections of the imbedding space gamma matrices to the space-time surface) and modified gamma matrices (defined as contractions with imbedding space gamma matrices of canonical momentum densities defined by action) are mixtures of M4 and and CP2 gamma matrices. As a consequence, M4 chiralities get mixed and only H=M4 × CP2-chirality is conserved and corresponds to the separate conservation of baryon and lepton numbers.

    It must be emphasized that the mixing is a direct signature for the space-time as a 4-surface identitification and distinguishes sharply and at very general level between TGD and competing theories.

Consider now the second option in which one would have heavy new boson decaying to top quark pair. The following short argument is modified from that appearing in the earlier posting.

  1. Already earlier both Jester and Lubos told that CDF sees 3.4 sigma top quark pair asymmetry in proton-antiproton collisions. The asymmetry would be roughly five times larger than predicted by QCD. The asymmetry requires that the quark-antiquark pair annihilating to top quark pair can do so by coupling not only to gluons and to a new boson which has axial or partially axial coupling so that interference term would produce the asymmetry.

  2. Axial vector color octet with rather strange couplings to quarks and leptons was suggested by the experimenters as an explanation of the finding. I do not however see any deep reason -correct me if I am wrong!- for why one could not consider also pseudo-scalar octet. TGD indeed predicts that all gauge bosons should be accompanied by scalars and pseudo-scalars with same quantum numbers: also gluons. Scalars should be eaten to give the third polarization to gauge bosons. Maybe the coupling to a pseudo-scalar variant of color octet Higgs could give rise to a contribution interfering with the contribution of spin zero virtual gluons and in this manner give rise to the asymmetry. Maybe there is simple objection but I am not able to invent it now. More complex option would be color octet excitation of Z0.

  3. The decays of pseudo-scalar gluon to top quark pairs might also explain the above described anomaly since the coupling would be strong so that at least orders of magnitude would be correct.

  4. Addition: Jester reports new data about the strange top-pair forward-backward asymmetry. For top pairs with invariant mass above 450 GeV the asymmetry is claimed by CDF to be stunningly large 48+/-11 per cent. 3 times more often top quarks produced in qqbar annihilation prefer to move in the direction of q. If true this would favor color octet excitations of Z0as the most natural explanation since the asymmetry would be not only due to the interference of vector and axial vector exchanges but also due to the inherent parity breaking of colored Z0 couplings. The effect would provide further support for the identification of color quantum numbers in terms of color partial waves rather than as spin like quantum numbers. The earlier support comes from the evidence for colored excitations of leptons.

    Addition: After a badly slept night I have come to new thoughts about the possible explanation of the effect. What is so weird (really weird when one begins to think the numbers!) that the outgoing top quark (t) remembers the direction of motion of quark q before annihilation to intermediate gluon which it should by the basic definition of annihilation diagram. For any exchange diagram the situation would be totally different: consider only Coulomb scattering! The quark q of the first proton would scatter from the quark of the second proton and transform to top quark in the scattering and keep its direction of motion in good approximation since small angle exchanges dominate due to the propagator factor. Flavor changing exchange diagrams are however not possible in the standard model world since the only flavor changing are charged weak currents and their contribution is negligible.

    In the new physics inspired by TGD situation is however different! The identification of family replication phenomenon in terms of genus of the wormhole throats (see this) predicts that family replication corresponds to a dynamical SU(3) symmetry with gauge bosons belonging to the octet and singlet representations. Ordinary gauge bosons would correspond besides the familar singlet representation also to exotic octet representation for which the exchanges induce neutral flavor changing currents in the case of gluons and neutral weak bosons and charge changing ones in the case of charged gauge bosons. The exchanges of the octet representation for gluons would explain the anomaly! Also electroweak octet could of of course contribute. Note that this mechanism would explain both anomalies associated with top quark production.

    What is fantastic is that LHC will soon allow to decide whether this explanation is correct!


Ulla said...

This is a bit off topic.

Can you explain the difference between p-adic hierarchy and hierarchies of Plancks constants (hbar)? This bothers me, look like they go into each other.
Then is also a kind of hierarchy in the fractality.

Matti Pitkänen said...

p-Adic hierarchy means hierarchy of different local topologies of space-time differing dramatically from real topology. The notion of nearness is totally different. p-Adically infinitesimal is infinite in real sense: in particular p-adic space-time sheets representing "thought bubbles" have literally infinite size in real sense. Cognition cannot be localized in brain. p-Adic smoothness (purely local probability) implies long range correlations in real sense (global property). p-Adic mass calculations give fantastic verification of this picture.

The hierarchy of Planck constants does not relate to local space-time topology (real or p-adic for some prime p) but to the book like structure of 8-D imbedding space - be it real or some p-adic variants of it. Each page of the Big Book defines its own universe and darkness is relative: what is at other pages is dark from the perspective of my page.

This book like structure could be postulated separately as I indeed did first. During last year I learned that could result from dynamics as effective property. The latter option is the minimal one and the non-linearity of field equations strongly suggests it. It takes few years to decide which option is the correct one.

Ulla said...

Sorry for my bad math skills. I know I have asked this so many times before, but always there are new turns.

p-adic = hierarchy of different local topologies of space-time differing dramatically from real topology, forming bubbles.
hbar = does not relate to local space-time topology (real or p-adic for some prime p) but to the book like structure of 8-D imbedding space - be it real or some p-adic variants of it.

But then the Big Book can be p-adic for entanglements forming a topological hierarchy (of algebra/rationals) OR a chaos of entropy. You say also the chaos is entangled as a bookpage, maybe as the unification of forces?

If reals are entropic, then algebra/rationals forming networks are negentropic. An analogy would be the Sea where wind (reals) are blowing up high waves of water (algebraic). They are totally different, still they can cooporate through dissipation? Force need something to act upon?

The hbar creates wormholes between similars only, according to energy and informational content, but the scaled up variants follow the fractality laws and are quantized?

Something like that? Robert Paster
but he talks nothing about hbars. I saw I messed these both up.


Ulla said...
Vitiello about fractals

Matti Pitkänen said...

It is very very (really!!) difficult to understand mathematics without mathematics - or anything without the proper context - and most attempts to communicate lead to misunderstandings and at best to an illusion of understanding. This has taught me how crucially important the academic institutions are for the transfer of understanding and contexts to new generations.

For instance, I could tell that topology is about continuity and nearness hoping that these concrete words would help. I could tell that p-adically infinitesimal is infinite in real sense.

But this creates only a bundle of associations having not much sense mathematically if one has no deeper idea about what topology really is (about incredibly many different manners of being near). About biology it is much easier to talk;-).

Mathematics is an incredible cultural achievement and it requires life long devotion to learn even infinitesimal portion of it. Just like good music, be it classical or jazz or something else which is developing new forms with amazing speed. Yesterday I heard soprano singing something from baroque with jazz band!

No one requires that modern composer should be able teach the tricks of trade to a layman or to make him a concert pianist within few days. It is however regarded as obvious that science popularizer is able to meet comparable challenges;-). Therefore popular science writers have become masters in generating emotions and creating the illusion of understanding. New Scientist is a good example of this.

Ulla said...

Soprano singing something from baroque with jazz band sounds very TGDish :) I like those odd compositions, and would gladly have listened.

You know I have tried to understand this for many years now, not only a few days, and this happens to be very central to TGD. I am frustrated and angry at myself for this. I looked at the brain and thought I understood, then I saw I didn't and I messed it up. Sick.

I do have an idea what topology is, because I work with it every day. It is the essence of reflexology. The same pattern repeats and repeats with saved contact to the origin, again and again, bigger and smaller parts, and I have got the wiev that it goes outside our body. Every new turn is like a glorious chorus :)

I do believe in populars, otherwise the reality science becomes totally isolated. But I have no time to learn math, you know that. I only need to 'see' the structure of it.

Was my analogy anything useful? Or the essay, both of them? You said you were my teacher, remember! Am I too demanding?

Then the soul thing. Links? I have seen it somewhere in these lots of pages.

L. Edgar Otto said...


From comments relating to you posts I am not sure I understand your key insight, and I feel you have not seen mine- perhaps because of the complexity of the language and the subject.

There are whole journals on Pascal's triangle and its properties. There is new evidence relating to Ramanujan. So in an attempt to understand you better I took an interesting diagram from my last post and put it into my "quasic" framework.

So, if you would look at today's diagram maybe we could reach some common and new ground. In many ways yours to mine is a more reductionist or scientific theory but perhaps not a pure as Kea's math.

In this top quark idea lurks further generalizations at but the beginning of such hierarchies. Could this have been predicted in the main by our theories as it seems the 3+1 concept involved here at least in the ideal form?

This chart of course can be extended into very high dimensions the one here only goes up to ten. In this notation as a help to visualization (the intuitive structural seeing of it as our friend desires) the values of some rather large figurate numbers are reduced to a cell in the search for patterns. Is there a limit to say 64K dimensions with these Fermat numbers involving the elegance of primes? 11n + 6 = 17 ?

Could you clear up a bit your insights involving 89 - all our theories seem to have haunting parallels. 89 = Xn + b

The PeSla

Matti Pitkänen said...

TGD based explanation of family replication phenomenon does not relate to space-time dimension but the identification of particles as 2-D wormhole throats. Orientable 2-D surfaces are characterized topologically by genus, the number of handles attached to sphere to get them. Sphere, torus, sphere with two handles are very special from the point of view of conformal invariance in that they allow global Z_2 conformal symmetry and this explains why three lowest genera are light/can be interpreted as elementary particles.

This is one of the signature of TGD and the prediction is flavor changing neutral currents for which recent anomaly gives support.

What is essential that prime 89 defines Mersenne prime: M_89 = 2^89 -1. Mersenne primes are very rare and it turned out that the most important p-adic primes correspond to Mersenne primes.

I can look your posting later. Just now I have a little bit hurry!