## Wednesday, April 6, 2011

### A Flying Fairy? No

New physics at CDF again? They report on a $3.2 \sigma$ peak at around $150$ GeV in the invariant mass distribution for dijets associated to WW production. But it can't be a Higgs fairy field. They refer to this thesis for further discussion.

Update: Tommaso describes the result and mentions this suggestion for a light $Z'$ boson. A small coupling to leptons is required by existing constraints on the $Z'$ mass, suggesting a preference for a (color like) $Z'$, coupling to quarks. Update: Tommaso seems to believe that Tevatron characteristics can explain away the bump.

#### 8 comments:

1. Matti Pitkanen also weighs in with a flavor changing neutral current hypothesis. I have also long been thinking about the effects of the $Z$ boson (color) triplet that arises from the twisted Fourier transform of leptons and quarks. It seems that most theorists who take the signal seriously (and it is a pretty bump) are leaning towards a $Z$ triplet of some kind, since this has the potential to also explain the top antitop forward backward asymmetry.

So, we do get new physics, it seems. But no fairies or zomby susies.

2. Recall also that back in 2009 we were musing about the connection between $Z'$ objects and the multi muon anomaly.

3. Note that the new (mass) peak sits around $2 m_{W} = 160$ GeV, which fits into a basic Koide triplet of form (for instance) $(1,2,4)$.

4. But let us be clear here: this should be seen as a new QCD effect associated to the Z boson. It should not be discussed in terms of an ad hoc $Z'$ state that just happens to couple to quarks.

Thanks to Marco Frasca for criticising the so called 'theory' community on Tommaso's blog.

5. E6 models in general predict there are two Z' bosons.

6. Yes, kneemo, I understand that the M Theory version will discuss Z' bosons. That is why I alternate between using the term Z' and carefully avoiding it (in my susy paper, for instance). What I want to know is: how long before a senior string theorist (besides Mottle) starts admitting that maybe, just maybe, they did not do the best job of guessing what kind of new physics will show up at the LHC?

7. Here is Tommaso's old post on a $3 m_W$ $Z'$ boson. Of course we always think in terms of particle triplets, here. So, measurements suggest looking at a dimensionless Koide triplet of

$\sqrt{m} \in (1, \sqrt{2}, \sqrt{3})$

for the set $(1,2,3) m_W$, along the lines of older discussions on fundamental Koide triplets for bosons (see above links on the multi muon anomaly, for instance).

8. And here are the new slides from Vivianna C.

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