

‘Penguin’ Anomaly Hints at Missing Particles - digital55
https://www.quantamagazine.org/20150320-penguin-anomaly-hints-at-missing-particles/

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jessriedel
> When the LHC resumes bashing particles together in May, LHCb scientists will
> continue tracking penguin decays in hopes that the anomalies in the data
> will climb to 5-sigma certainty, signifying an indirect discovery of “new
> physics.”

Large sigma values only rule out statistical fluctuations, not systematic
errors.

Adam Falkowski's Resonaances is the go-to particle physics blog for these
sorts of stories. On this particular anomaly he has this:

> The measurement moved a bit toward the standard model, but the statistical
> errors have shrunk as well. All in all, the significance of the anomaly is
> quoted as 3.7 sigma, the same as in the previous LHCb analysis...So how
> excited should we be? One thing we learned today is that the anomaly is
> unlikely to be a statistical fluctuation. However, the observable is not of
> the clean kind, as the measured angular distributions are susceptible to
> poorly known QCD effects. The significance depends a lot on what is assumed
> about these uncertainties, and experts wage ferocious battles about the
> numbers. See for example this paper where larger uncertainties are
> advocated, in which case the significance becomes negligible. Therefore, the
> deviation from the standard model is not yet convincing at this point. Other
> observables may tip the scale. If a consistent pattern of deviations in
> several B-physics observables emerges, only then we can trumpet victory.

[http://resonaances.blogspot.ca/2015/03/lhcb-b-meson-
anomaly-...](http://resonaances.blogspot.ca/2015/03/lhcb-b-meson-anomaly-
persists.html)

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trhway
curiously, looking at the article's graph

[https://www.quantamagazine.org/wp-
content/uploads/2015/03/LH...](https://www.quantamagazine.org/wp-
content/uploads/2015/03/LHCb_Graph-300x209.jpg)

what i see is that SM generates completely different prediction curve than the
experiment results. It isn't just a 4th and 5th bin there SM predictions are
different from the experiment results - as far as i see the whole
[interpolated] curves are different. The SM generated one is much steeper and
kind of like goes extremal with energy increase what is typical for physical
theories when they hit borders of their applicability while the experimental
results behave pretty well, i'd say even beautiful, into the higher energies.
It looks like SM is really due for correction which should also affect its
predictions for smaller energies - while may be measurement wise the
difference between predictions and results in the first 3, lower energy, bins
may be not that big, it is obvious from the curve steepness that SM describes
different physics than experiments show, and that the same difference just
grows and becomes obvious at 4th, 5th bins...

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PhantomGremlin
The article has a different way of thinking about the "shattering" of
colliding protons. Perhaps this is a long standing "in joke" among particle
physicists, but it was the first time I read it:

    
    
       The hopes of thousands of particle physicists
       are riding on the protons that in the coming
       years will collide there, shattering into
       petabytes of data that may carry long-awaited
       answers to fundamental questions about nature,

