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CMS sees excess of same-sign dimuons "too"

An Xmas rumor deja vu

There are many LHC-related hep-ex papers on the arXiv today, and especially

Searches for the associated \(t\bar t H\) production at CMS
by Liis Rebane of CMS. The paper notices a broad excess of like-sign dimuon events. See the last 2+1 lines of Table 1 for numbers.

Those readers who remember all 6,000+ blog posts on this blog know very well that back in December 2012, there was a "Christmas rumor" about an excess seen by the other major LHC collaboration, ATLAS.

ATLAS was claimed to have observed 14 events – which would mean a 5-sigma excess – of same-sign dimuon events with the invariant mass\[

m_{\rm inv}(\mu^\pm \mu^\pm) = 105\GeV.

\] Quite a bizarre Higgs-like particle with \(Q=\pm 2\), if a straightforward explanation exists. Are the ATLAS and CMS seeing the same deviation from the Standard Model?

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snail feedback (19) :

reader Uncle Al said...

Stipulated: There exists a 105 GeV/c^2 Higgs.
Question: What does that leave of the Massed Standard Model?

Comment: Q = ±2. giggle Parameters for sale! Get your curve fittings three for the price of two for a limited time only! Buy ten, get 3 sigma off a perturbation treatment at your local spa. Particle physics is become FNORD. [Principia Discordia (1965), The Illuminatus! Trilogy (1975)]

reader Luboš Motl said...

Sorry, you can't randomly change charges of particles. There is no a priori obvious, canonical model with a Q = ±2. Higgs boson. The idea that there is is just your fantasy caused by your complete misunderstanding of modern physics.

reader strictly speaking... said...

Does a new particle explaining the resonance have to be a scalar Higgs-like boson? Or could it be say, a new W-like gauge boson?

reader strictly speaking... said...

Or a 3-stop bound state?

reader strictly speaking... said...

Assuming they haven't explicitly ruled out a neutrino excess or have detailed polarization measurements.

reader Luboš Motl said...

LOL, great proposals.

It would surely be quite a revolution if the charge-two particle were a gauge boson.

According to things we know, massive elementary gauge bosons should be uniquely associated with broken generators of a Lie group - the gauge group. I think that there is no "simple enough" gauge group whose generators would include generators with Q=1 (known W-bosons) as well as Q=2 (the new ones).

Well, in principle, you could extend the electroweak SU(2) to an electroweak SU(3) or larger, and then you could have more complicated charges under the electromagnetic Q, but you would also predict lots of new particles - quarks would have to be electroweak triplets or worse, and so on.

Bound states of N top quarks have masses comparable to N times mass of the top quark plus minus a small multiple of the QCD scale (below 1 GeV), I think. So you can't easily get far away from 350 GeV, 520 GeV, and so on.

reader Uncle Al said...

Contemporary physical theory is a dog's breakfast of parameterizations, curve fittings, epicycles, and apologies. Everything can be rationalized with perfect equations, even superluminal muon neutrinos.

Theory should be elegant, terse, and predictive. When it is not, it has one or more defective founding postulates. Do not write more theory or rationalize "confirmation." Break defective theory with heterodox observation to locate the defective postulates.

reader Luboš Motl said...

No competent theorist has ever seriously considered the possibility that neutrinos are faster than light.

The physical image of the world as we have reached it by the early 21st century is beautiful, concise, unified, sensible, far-reaching, universal, and quite possibly very close to the final picture i.e. the mind of God – and all the negatively sounding adjectives are completely irrational.

Have you ever had the courage to consider the possibility that your attitude against contemporary physical theory is negative because the content of your skull, and not contemporary physical theory, is a stinky pile of crap?

This is not a rhetorical question but a real question and I do demand an answer from you, otherwise I will ban you.

reader Tony said...

Can anybody explain how do you arrive at 5 sigma excess from 14 events? I know what standard deviation means, just wondering what are the exact steps by which one follows from another?

reader Gene Day said...

Current theoretical physics is incredibly rigid. Suggesting that it is a “dog’s breakfast” is beyond stupid. You really have to start over, Uncle Al.
As a beginning, re-view Nima Arkani-Hamed’s Nov. 6 talk at the Perimeter Institute and come back when you get it. If you choose to argue with Nima and Lubos you are hopeless.

reader Tony said...

Let me try myself first: in the given experiment, had they found 3 events more than expected by the SM, it would have been within 1 sigma, so no biggie, I guess. But they found 14 more so it is about 5 sigma from expected value? Is that how it works?

reader jim z said...

The actual events observed vs the probability that accidental or coincident recordings of the detectors could be observed (non-events).

reader jim z said...

If the like probability of a false positive is once in each one million years, three positives in ten seconds is more than one SD.

reader jim z said...

You flip a coin 14 times and get 14 heads in a row. (You could have a two headed coin or you might have a heads-tails coin.) To five sigma (whatever, didnt do the maths), you probably have a two headed coin, not a heads-tails coin.

reader Justin said...


Would you be interested in waging a bet on SUSY by 2018? I'll give you 100 to 1 odds.

reader Luboš Motl said...

Dear Tony, 5 sigma is just an equivalent way to say that the probability that 14 or more events is 1 / 3 million (the usual probability with 5 sigma).

When the predicted mean number of events is N, the probability that the expected number is M follows some Poisson distribution. The smaller N is, the more this distribution falls with M.

Here, the expected mean N is some constant below 1 you may calculate if you wish, and if you just calculate the probability that you get 14 or more, you will get 1/3 million.

reader Luboš Motl said...

I would find this offer absolutely irresistible if I would believe that you will actually be able and honest to fulfill the commitments.

reader Justin said...

I'm 100% honest. I'll give you full contact information. In fact, because I know you're a moral person -- in this regard -- I'll prepay you. Now, we're only scaling $1. So, I'll send you $100 dollars immediately. When 2018 is up, if there's no SUSY you will have to give me back $101.

Okay, here's the catch: When 2018 is up, if there's no SUSY, I require that you write a single blog post which reads exactly as follows.

Begin Blog Post:

"On this day, January 1, 2018, I Lubos Motl hereby confess that I am an arrogant stinky asshole. For the last 40 years, I and other clueless pseudo-physicists have dedicated their lives to a theory which has not provided a single relevant insight into nature. As a punishment for my intellectual disability, I hereby pay Justin X exactly $101.00. It is hoped that this monetary transaction teaches me a lesson sufficient to increase my mental ability to the level of understanding that string theory and supersymmetry are the deepest fantasies of my mind, but nothing to do with physical reality."

End Blog Post


reader Luboš Motl said...

Dear Justin, up to the $100/$101, it was OK and I would immediately accept it even though I had a $10,000 bet - like with Adam Falkowski - in mind.

However, you would have to add a $10,000 fee for your extra obscene idiotic commercial.

String theory and supersymmetry belong among the most valuable parts of knowledge that the mankind has accumulated.

And I will surely be no *expletive* if SUSY is not found at the LHC. It is not known whether it will, and it was never known. And my estimates of the odds that the LHC will find SUSY were always - and remain - close to 50%, start e.g. with this 2007 blog post.


Your clearly stated agenda - attempting to post obscene lies whose value is $1, literally - shows that you're not the target audience of this blog - which is mostly people 3-8 orders of magnitude more valuable than you - so I blacklisted you. Feel free to comment on websites dedicated to readers of your value. I can enumerate quite a few.