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Another CMS 2.6-sigma SUSY excess

Edge at \(m_{\rm inv}=79\GeV\) in dilepton events

There were virtually no deviations of the LHC from the Standard Model a month ago. But during the last month, there has been an explosion of so far small excesses.

Off-topic: Have you ever played 2048? Flash 2048. A pretty good game. Cursor arrow keys.
One day after Tommaso Dorigo presented another failed attempt to mock the supersymmetric phenomenologists, he was forced to admit that "his" own CMS collaboration has found another intriguing excess – namely in the search for edge effects in dilepton events.

The detailed data may be seen in Konstantinos Theofilatos' slides shown at ICNFP2014 in Κολυμβάρι, Greece (if the city name sounds Greek to you, it's Kolimvari; Czech readers may call the place Kolín-Vary) or at a CMS website. The paper hasn't been released yet but it's already cited in the thesis by Marco-Andrea Buchmann (no idea about his or her sex but he or she looks like a boy) whose chapter 5 (page 49) is dedicated to this search (see also the reference [95] over there). On page ii, Buchmann mentions significance of the edge at 2.96, almost 3 sigma.

What's going on?




Supersymmetry is expected to preserve, at least approximately, the multiplicative conservation law for the R-parity. The known Standard Model particles have the positive R-parity; their elusive superpartners have the negative R-parity. We collide known and boring protons only so the initial R-parity is positive (even). So if superpartners are produced, they have to be produced in pairs.




Each of the superpartners may decay and the process of decay may have several steps. Either missing energy (neutrinos or, at the end, the lightest superpartner) are released, or charged leptons. Charged leptons are "clean" and not too contaminated by the hadronic junk that the LHC constantly produces in the proton-proton collisions.

In the decay chain, two charged leptons, e.g. one \(e^\pm\) and one \(\mu^\pm\), may be released as a superpartner decays to lighter superpartners via the chain \[

X\mathop{\to}_{e^\pm} Y\mathop{\to}_{\mu^\pm} Z.

\] Their invariant mass can't be arbitrarily high. The maximum value is equal to the mass difference between the masses of \(X\) and \(Z\) i.e. \(m_X-m_Z\).

(The actual search looks for same-flavor, opposite sign leptons i.e. \(e^+e^-\) and \(\mu^+\mu^-\).)

The reason why this is really the maximum invariant mass of the charged leptons is that it is clearly achieved if the two leptons' momenta are parallel in the spacetime, along with everything else. If they are not parallel, the invariant mass is lower than it could be.

So the dileptons resulting from the decay of the superpartner \(X\) with the invariant mass \(m_{\rm inv}(e^\pm \mu^\pm)\) above a threshold (edge) don't exist at all. On the other hand, lots of dilepton events are predicted "right beneath" the edge because they correspond to relatively slowly moving leptons and there's a lot of phase space over there because the invariant mass only depends slowly on the speeds if the speeds are low.

To make things clear, one would like to see something like this:



The chart was produced by a computer simulation. The green dotted curve shows the shape of the expected edge at \(m_{\rm inv}=65\GeV\) and you may see that the shape is matched by the observed (but simulated) events, the black curve.

The actual observed curves from CMS look much less spectacular,



but the mild edge located at \(m_{\rm inv} = 78.7\pm 1.4\GeV\) (Buchmann's thesis) was actually quantified to have significance 2.6 (the Greek guy) or 2.96 (Buchmann) sigma, formally corresponding to something like 99% or 99.7% certainty that new physics is there. Of course, a 99% certainty is nothing convincing in particle physics and most things one may be 99% certain about are almost certainly flukes or errors.

(The reason of the discrepancy is really the same as the reason why the sleeping beauty knows that the probability of "tails" is still \(P=1/2\). She wakes up after "heads" twice as often but she knows that; she knows that the heads – and similarly excesses at the LHC – are "overreported". So if she wants to have an idea about about the actual probability of the new physics or heads, she must correct her estimates for this overreporting. When she does so, she knows that heads still have \(P=1/2\), less than the naive \(P=2/3\), and new physics given the excess is much less likely than the formally calculated and often incorrectly interpreted 99%.)

But it's surely another fluctuation that can keep one excited.

If you have been searching for masses in \({\rm GeV}\) in this blog post, you must have seen that the relevant edge was at \(78.7\GeV\) or so. If superpartners exist, this value could be the mass difference between two superpartners (or other new particles?) waiting to be discovered.

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reader Tom said...

Gene, can you point to a video with Obama speaking extempore where he appears deep and profound on any subject? I certainly can’t. On the other hand, look at that video from last week, the “hatin” one. That is the face of a man so far gone in narcissism as to approach solipsism.


reader cynholt said...

Keep in mind, the coup in Kiev wasn't the result of a popular uprising in Ukraine. It was engineered and backed by a foreign power (Obamanation). Therefore, self-determination was out the window as soon as the elected leader of Ukraine was illegally and forcefully ousted (by the neo-Nazi stooges of the foreign power).

Left to themselves, the people of Ukraine would probably have waited until the next election, which was scheduled in 2015, to pursue an electoral solution. Too late for all that now. Ukraine is a geo-political chessboard.


reader cynholt said...

The US government created this crisis to disrupt the region, as it has done in so many other places around the world. Confronting Russia is the strategy. Maintaining the US dollar as the world's reserve currency, so that US hegemony can continue, is the goal. We haven't and won't see the US government offering anything but provocation and lies.

What's less clear is how Russia will respond, but they've been consistently saying they won't allow Russian-speaking federalists in Ukraine to be killed or oppressed.


reader Tom said...

Actually, Cynholt, I try not to keep this stuff in mind. Matter of fact, I got rid of my TV a couple of months ago and feel much better having done so. Power is power, and what happens on the marches of the world’s largest country is in the “physics” of it all. Personally, Putin doesn’t worry me at all, ill treatment of oligarchs or not. (How about Obama’s ill treatment of Ramesh Ponnuru?) The comparisons with Hitler are well beyond ludicrous.


reader cynholt said...

My hope is that this crisis will resolve with progress towards a multi-polar world that diminishes the current uni-polar domination of the US empire. I see that as possible at this point. More than that, I want to see a resolution that avoids world and nuclear war, regardless of the geo-political positioning.
Despite what EU leaders are saying, they certainly understand that this crisis is hurting them and will be less and less inclined to go along with US dictates.

The economic domination of the US dollar has been waning since the 90's and now is in serious danger of toppling entirely, which is both why the US is so aggressive militarily and why US power and influence have diminished.

If we can get past the confrontation of Russia without another world war, or the use of nuclear weapons, there's a better chance the US empire will fade quietly. Unfortunately, US world power will be prolonged if Russia either backs down entirely, or gets dragged into a long civil war in Ukraine. I'll take that over world or nuclear war though. I don't have confidence that US leaders will be careful to avoid a big confrontation. I have more confidence in the Russian leadership, but they're being backed into a tight corner over there. The US leaders have obviously been the instigators and aggressors all over the planet. If US citizens could rise up against this aggression, it would help immensely.


reader Tom said...

Thanks for the link, Edwin, what a motherlode of mathematics! Anyone interested in Navier-Stokes (Clay prize) should read this: http://terrytao.wordpress.com/2007/03/18/why-global-regularity-for-navier-stokes-is-hard/


reader anna v said...

Good job Lubos, in elucidating the analysis. That MET in the Kolymbari presentations put me off the track:) It should be actually Missing Transverse Energy, but they are using the insider MET instead of ME_t .

Well,the thesis are ripening and we should see more of the same from both experiments.


reader Svik said...

Does atlas show a similar bump at 79gev or elsewhere? Could the single data point be due to the cms detector construction discontinuity?

Or do we wait for a sigma 3.84 result. ;--(


reader Gene Day said...

Upon re-reading all of the responses to this post, it is obvious that almost every response is a wildly distorted attempt to mold the facts into the writer’s prior and unalterable world view.
That is, in fact, the problem; is it not?


reader Gene Day said...

As Putin said, economic warfare tends to boomerang. So does hot war.


reader mesocyclone said...

"Peer reviewed science"?? This is a physics blog, where real science often is discussed. A couple of social "scientists" in the US don't count.

In the US we have diverse media. They don't all sing the same tune. We can find strong divergences in viewpoint, and that's important. It means that we do not have an oligarchy, regardless of what a couple of pinheads wrote.

As to the Russian media valuing truth... don't be absurd. I have seen the "truth" value of the ironically named Pravda. It puts out continuous propaganda. I guess it works, since you seem to believe them.

As to the quality of the political class, I'd take ours over the psychopaths and petty thieves of the Russian class.

None of this would matter much if Russia wasn't constantly supporting movements outside its borders which are doing evil - for example, Syria's Assad.


reader Luboš Motl said...

I know the name of David Černý primarily because his ex-GF was filming a TV document about me - but to claim that a person familiar with the Czech Republic must know David Černý is really amusing!


reader Svik said...

Kiev has already killed 1500 innocent east Ukrainian civilians supported by u.s. and harper here in Canada. Tjos isbveru dangerous as Those who promote violence will reap it.


reader RAF III said...

Gene - I was about to agree with you when it occurred to me that they were all 'pixilated' -

https://www.youtube.com/watch?v=75Ic6hPsgmk
check 8:25 to 9:40 and then from 22:30...
I'm not sure where this leaves the two of us.
Cheers


reader anna v said...

we have to wait for the similar study to be released by Atlas.


reader ny-ktahn+CourseRegistration said...

I think both leaders are smart enough to judge the ramifications of an escalated crisis. However I am sure there are a lot of extended marginally relevant third parties that can use this opportunity to promote a lot of garbage, and attempt to capitalize on this. There are never dragons just bad rhetoric and propagandist. This too shall pass.


reader contradiction prediction said...

Lubos, they finally put up the videos for Strings 2014.

http://physics.princeton.edu/strings2014/Talk_titles.shtml



Witten didn't say much, just welcomed everyone and gave a history of the hall they met in.


What do you think about the 'vision' talks? Also, there are two poster sessions that talk about constraints on M-theory that would be interesting to see.


reader papertiger0 said...

The BBC complaining about "the few" controling both government and media.


That's fucking rich.


reader contradiction prediction 2 said...

At Strings 2014 Witten indicates there are roughly 600 theorists at the conference. That's impressive.


reader cynholt said...

In the final analysis, all this warmongering in DC is about trying to maintain the supremacy of the proverbial, almighty US Dollar. Iraq dared to want to sell its oil in Euros, and it was invaded. Libya was spearheading a gold based pan-African currency and it was invaded. I think the BRICS though, will survive as China, Russia and India (surprise, surprise) are major economic engines now.


reader Gene Day said...

I get it. You and I are the only sane ones and you’re not so sure about me.


reader Linda Serena said...

You appear to sing your mass medias' song which is, contrary to your opinion, not only totally homogeneous but also untrue.


The US has now disrupted and destroyed a significant part of the globe and they are responsible (together with the Saudis) for the creation of the ISIS monster. Libya may be the next country to join ISIS, followed by Syrai and Lebanon. ISIS next intermediate target will be Mecca and Medina, and they do not even have to invade Saudi Arabia because they are already there. If they take over Pakistan, perhaps in a similar fashion like Northern Irak, they will possess nuclear weapons.


Now, that there is a real threat to all world civilizations, the US just steps back and let everyone else deal with it, worse, they created another, totally unnecessary disaster in Ukraine. What they should really do now is listen to countries with a real and intelligent long term policy such as Russia or better just let Russia dictate the US foreign policy, just not to disrupt the world even further.


reader Tom said...

I pretty much agree with your stuff on the dollar, although I think it is only luck keeping the dollar up - most currencies (excepting, of course, the Swiss) suck even worse than ours. It’s a very low probability event that all this world-wide money printing will not cause an unprecedented economic disaster.


reader John Archer said...

"Aye. All t'world's queer, save thee and me ... and I wonder about thee sometimes."

Every Yorkshireman's first words. If he repeats them at you, duck before the follow-up, unless you want a bloody nose.

So, what part do you hail from then, RAF III? :)


reader papertiger0 said...

US becomes worlds leading oil producer, overtaking Saudi Arabia and Russia.

London: The US overtook Saudi Arabia and Russia to become the world’s biggest producer of oil as extraction of energy from shale rock strengthens the nation’s economy, Bank of America Corp. said. US production of crude oil, along with liquids separated from natural gas, surpassed all other countries in the first six months, the bank said in a report on Friday. The country became the world’s largest natural gas producer in 2010. A commerce department decision to allow the overseas shipment of processed light oil called condensate has fanned speculation the nation may ease its four-decade ban on most crude exports. “America is now the world’s leading producer of oil and gas,” Francisco Blanch, the bank’s head of commodities research in New York, said in the report. “The American shale revolution has had a transformational effect on the US and global economies in recent years. Low energy prices are a key edge of the US economy.”

Read more at: http://www.livemint.com/Industry/h9pdJRqVPUslM6bzyssK9N/US-becomes-biggest-oil-producer-overtakes-Saudi-Arabia.html?utm_source=copy


reader cynholt said...

Obama is like an angry, belligerent guy in a bar. Any time a fight
breaks out, he has to jump into it, without even knowing what it's all
about.


reader mesocyclone said...

Hmmm.... the media controllers must have an amaszingly long reach, given that I get my news every day from about 25 outlets all over the world. Those outlets are not even close to homogenous. For example, that this site taught me about the Ukraine ethnic make-up before any western media carried it, but then the media caught up. The western media do get things wrong a lot, mostly due to biases in the
reporters, not due to any conspiracy (although there is a consistent progressive bias in the "mainstream" which is why I go to more sources. But, they almost never fabricate
news, and if you use a wide variety, as I do, you can get a pretty good
idea of the truth.

On the other hand, you sound like a propagandist for RT.

I studied propaganda for a long time. I was a regular listener to Radio Moscow and Radio Havana way back in the 1960's. I also visited a US counter-propaganda station in Europe at one point, and saw the means they used to dodge the incessant Soviet jamming. I remember when RM cleaned up their act in the early '80s, at the same time that the US MSM went downhill, to the point that on some subjects, RM was as credible (but only in a limited area), but at that time both were tilted quite badly, ironically in the same direction. I also have enough personal contacts in various countries and ( in the past ) in various agencies that I can or could check out a lot of stuff. I usually know when I'm being lied to. I see lies that come out of mainstream Russian media so bad they would never appear in any reputable US media.


reader cynholt said...

Well, when the investigation is over, the rebels can go back to spanking the Ukrainian killers. Better sooner than later as clearly Poroshenko's only taking advantage of the hysteria to continue his campaign of ethnic cleansing.


reader Svik said...

It could be 5 years before this is confirmed. Same for bicept3 and lhc14.

Better find some problem worth burning more coal over. Super computer run on coal you know. ;--).


reader Svik said...

It a lot of work to sift through the dross!!!!

I looked at consortium news.com re the buk. It looks like the Kiev Ukrainians did shoot down the plane thinking it was a Russian spy plane since the mh17 was expected to fly south of donesk. The may have actually thought it was Putin himself.

The us has said they have pictures showing Ukrainian uniforms at the buk. And there are no us sattelite photos to prove the rus did it.

So the kievittes and supporters are doubly guilty after all.


reader Gene Day said...

I think it is obvious that the Russians didn’t do it. I’m not sure which side did it but it is more likely that Russia supplied the advanced missile systems to the Ukraine (at an earlier date) than to the dissidents in the east.

I don’t think it really matters because it was clearly an accident. No one would have anything to gain by killing almost three hundred innocent people. Some people may think that either side did it in the hope that their enemies would be blamed but that is not how things work in warfare. The kill is all that matters, not some devious plot, when you are at war.


reader Mark Luhman said...

Most measure on health care is access not outcome. It matters little if you have easy access with bad out comes. That that 11th ranking an place it in the trash. I lived in a state with a healthy medical community servicing Canadians whom would not wait for their health care to get to them. America education system is in decline, somehow volume has replaced quality, funny we get less of both. If you were to measure European and Asian decent of the US population groups against the world we are still in the top 5% in education out come. America demographic have change in the last 50 years that were most of our so called problems are coming from in almost all aspects, as to whether is will be positive or negative time will tell. Anyone who discount the US is a fool, we still control within our borders most of the worlds energy and that a huge plus, the only question is can we get a handle on the corruption problems that have emerged in the last fifty years lead by the Democrat parity, Obama is only a symptom of the disease that now inhabits the Democrat party, as is Pelosi Kerry and Reed. Those sixty radicals are now in control of that parity and the results are not good. A honest media would be the first step unfortunately the same group of radicals exist there. The problem with sixty radicals the truth is never been part of and conversation with them since they been lying to themselves for so long they would not know the truth if it smack them right between the eyes. As to the Ukraine problem, I am saddened by the events there, it looks to me that Russia is treating Ukraine like it always has. As far a s Russia it a country only on a map, it really a state to Russia which Russia must control and exploit..


reader Svik said...

I would agree that it was accidental (mistaken identity) but if the u.s. side did it, it is really rotten to blame the other side.


reader aqua said...

I personally obtained (1/L,0,0) for your exercise. Did you correctly distinguish the upper and lower indices when computing the star-product? It's like computing the star-product in the Euclidean 3D space contoh bisnis rumahan , but then you must change either the sign of the time coordinate or the sign of the spatial coordinates (convention for epsilon).

Nevertheless, there are only two Lorentz-invariant meanings what the formula can mean - and they differ by the sign of the cross product term. Try both of them. My calculations show that one of them gives you (1/L,0,0) and the other gives you (3/L,2/L,2/L).


reader Wizard said...

so when you talk about the spinning of the strings...you mean "spin" in the classical spinning top sense? or the QFT conserved quantity due to symmetry sense?



And also...are you modelling the strings as perfect spheres? or does it take some other geometry?


reader Luboš Motl said...

Dear Wizard, the angular momentum is always exactly the same thing. It is the quantity conserved due to the rotational symmetry whenever this symmetry holds.


The angular momentum of a spinning gyroscope isn't a "different sense" of the angular momentum. It is exactly the same sense of the angular momentum - made explicit in one particular situation.


Also, in any situation where objects or their parts are moving through space, the angular momentum from the motion is given by pretty much the same formula, i.e. as the sum of


r x p


from all the "parts" of the moving object. It's the cross product. So the angular momentum of a vibrating string is given by the integral of


r x p


over the string (where p is the momentum density on the string). It is absolutely analogous to the rigid gyroscope. It can't be otherwise.


Strings are not perfect spheres. Strings are strings, one-dimensional strands or curves. But just like spherical or any other rigid objects, they are composed of points that are moving by different speeds.


reader Leo Vuyk said...

"Strings are not perfect spheres. Strings are strings, one-dimensional strands or curves. But just like spherical or any other rigid objects, they are composed of points that are moving by different speeds."

So if I imagine different connected point on a spinning propeller, then the central points have slower speed than the outer points of the propeller electron.?


reader Leo Vuyk said...

If that electron propeller has two spin axes, then these points should form something like a Calabi Yau surface?


reader John Archer said...

EU MILLIONS PAID FOR UKRAINIAN GROUPS BEHIND YANUKOVYCH OVERTHROW.

"The European Union pumped €436m (£348m/$586m) into Ukraine's anti-Russian "civil society" groups in the seven years leading up to overthrow of the democratically-elected President Yanukovych in February this year."

As Richard North puts it in his Ukraine: the EU millions:
"A myriad of small amounts, paid to hundreds of organisations, serve to build a supporting constituency, which gives the impression of a far more wider level of public support than is actually the case. Basically, control of civil society organisations gives control of civil society. And Ukraine was given the full treatment."

When the time comes to man the firing squad on these EU bastards I think they should chose the lucky team by lottery. There'll be plenty of punters and they could use the proceeds to fund show trials for their accomplices in our own Trojan branches of "civil society", followed by more firing squads.


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reader Leo Vuyk said...

To imagine the double spin of Fermions into a Calabi Yau surface see this video fragment:

https://www.flickr.com/photos/93308747@N05/10730447403/in/photostream


reader Sven said...

It is not clear to me whether the 2.6 sigma contain the LLE effect...?

Sven


reader Eric said...

Rough estimate: 2 times 2000 experimentalists. Teams for analysis are about 50. On analysis is at most 6 months. So: 80 teams, remove the overhead, 60 teams. 120 analysis/year. In 1 year, you would expect one to be above 2 sigma. 3 sigma may be a bit large, but experimentalists are usually optimistic about significance. As a rule of thumb, two or 3 "3 sigma" effects occur every year, and disappear later... So do not get excited about this.


reader Leo Vuyk said...

The propeller shape of fermions has important consequences described in my Quantum FFF model.
On consequence is that black holes have an electric potential and produce proton electron plasma.


According to Quantum FFF Theory, “New Paradigm Dark Matter Black Holes produce Proton– Electron plasma from the chiral Higgs vacuum outside the fermion repelling horizon nr 10 . The “Lighter” electrons will stay outside the “heavier” proton horizon (blue) by the strong Casimir -Higgs vacuum repelling gravity on the BH.
As a consequence of both attraction and repulsion forces, BHs have a strong electric potential, which is liberated by asymmetric processes in dual BH systems like Herbig Haro objects showing strong electro magnetic effects in open cluster star formation and Birkeland Alfven circuits around the earth and possibly even in BICEP2 B mode results.. Even Ball Lightning micro BHs seem to produce plasma as BL photos seem to prove..

see also: "the impossible electric black hole" <a href="http://vixra.org/pdf/1402.0044v2.pdf"


reader Sven said...

That somewhere a 2.x sigma effect must show up is clear. The question is the significance within this one analysis (i.e. whether the LLE effect within this particular analysis was included.)

Sven


reader Leo Vuyk said...

One of the stringy electron positron formation into compound quarks, is that out of the Higgs field vacuum hydrogen and water can be produced around micro-dark matter black holes inside Comets like Hartley2 and the recent observed 67P, see: https://www.flickr.com/photos/93308747@N05/14856397511/in/photostream


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