Physicists Detect Whiff of New Particle At the Large Hadron Collider (sciencemag.org)

sciencehabit quotes a report from Science Magazine: For decades, particle physicists have yearned for physics beyond their tried-and-true standard model. Now, they are finding signs of something unexpected at the Large Hadron Collider (LHC), the world's biggest atom smasher at CERN, the European particle physics laboratory near Geneva, Switzerland. The hints come not from the LHC's two large detectors, which have yielded no new particles since they bagged the last missing piece of the standard model, the Higgs boson, in 2012, but from a smaller detector, called LHCb, that precisely measures the decays of familiar particles. The latest signal involves deviations in the decays of particles called B mesons -- weak evidence on its own. But together with other hints, it could point to new particles lying on the high-energy horizon. "This has never happened before, to observe a set of coherent deviations that could be explained in a very economical way with one single new physics contribution," says Joaquim Matias, a theorist at the Autonomous University of Barcelona in Spain. B mesons are made of fundamental particles called quarks. Familiar protons and neutrons are made of two flavors of quarks, up and down, bound in trios. Heavier quark flavors -- charm, strange, top, and bottom -- can be created, along with their antimatter counterparts, in high-energy particle collisions; they pair with antiquarks to form mesons. In their latest result, reported today in a talk at CERN, LHCb physicists find that when one type of B meson decays into a K meson, its byproducts are skewed: The decay produces a muon (a cousin of the electron) and an antimuon less often than it makes an electron and a positron. In the standard model, those rates should be equal, says Guy Wilkinson, a physicist at the University of Oxford in the United Kingdom and spokesperson for the 770-member LHCb team. The new data suggest the bottom quark might morph directly into a strange quark -- a change the standard model forbids -- by spitting out a new particle called a Z9 boson. That hypothetical cousin of the Z boson would be the first particle beyond the standard model and would add a new force to theory. The extra decay process would lower production of muons, explaining the anomaly.

Comments

There's a fart joke in here somewhere

[DatbeDank]

I can smell it.

Re: There's a fart joke in here somewhere

[penandpaper]

He who articulated it particulated it.

Oh sorry, that was me

[rsilvergun]

I had a quantum burrito for lunch. The worst thing was that as soon as I opened the wrapper the wave form collapsed and it got all over my cloths.

good writeup from mfb

[Anonymous Coward]

..over on physicforums.

https://www.physicsforums.com/...

Re:Smell-o-vision

[king neckbeard]

Mosts atoms smells like plum pudding.

Physicists are getting desperate

[mjpvirtual]

A year and a half ago, a 3.5 sigma 750 GeV bump appeared in the LHC data. New physics was heralded and a hundred theoretical papers attempting to explain it appeared. It was a statistical fluke and disappeared as more data was collected.

Now we're faced with a 2 sigma anomaly and the shouts of new physics are once again repeated. This is even more likely to be noise.

Physicists have been predicting new physics for 30 years. It was a major justification for the promotion of the LHC project. Nothing has been found. There's a lot of desperation at work here. It's sad.

For a good summary of all of this from a CERN experimentalist who called the 750 GeV noise, see Tommaso Dorigo

Re: Physicists are getting desperate

[getuid()]

"Getting desperate"?

Projecting, much?

I have news for you: this is not Silicon Valley stupid.

Lack of "innovation" (i.e. new physics) is in itself a already good result. The LHC doesn't need any new shiny discoveries to justify itself. The very action of having looked for the first time in a certain place (or energy range) and having solid confirmation that there's nothing new to see would already be an outstanding scientifical result.

And everyone at CERN knows this, as does any scientist worth their spit.

Re: Physicists are getting desperate

[Anonymous Coward]

A lot of new research , knowledge and papers are coming out of LHC - you just don't hear about it because it is so esoteric. Hell even 'ancient' Fermilab is still operating and doing useful but mind-numbing-to-layman research.

Re:Physicists are getting desperate

[Lord Crc]

Now we're faced with a 2 sigma anomaly and the shouts of new physics are once again repeated. This is even more likely to be noise.

From what I understand the main difference between the 750GeV bump and this anomaly is that the 750GeV was a single bump which did not have a nice-fitting theoretical explanation while still being compatible with existing measurements.

This anomaly might only ~2 sigma so far, but it is ~2 sigma in several channels, so not just "one bump", and it seems one can rather easily and naturally extend the theory to match observations.

https://arxiv.org/abs/1703.09189

Wish

[phantomfive]

I'll be honest, I wish I understood this, but I don't.

Not really a Good Result

[Roger W Moore]

Lack of "innovation" (i.e. new physics) is in itself a already good result.

Not really. Lack of new physics means that we have no explanations for the myriad of things which need new fundamental physics to explain sch as what is Dark Matter? and why is the Higgs boson so much lighter than the scale of quantum gravity? By the end of this run in 2018 we will have covered about half the phase space that the LHC can reach and the high luminosity LHC upgrade will provide the other half...over the next ~15-20 years because increasing luminosity is not as good as increasing energy.

This is not good news because it may mean that new physics is beyond the reach of the LHC and whether the world can afford to build a new, even bigger machine is far from certain. However we have zero control of the result - either the universe works in a way where there is new physics in reach of the LHC or it does not. So not seeing anything is far from a failure...but that does not make it a good result. Indeed I have always referred to it as the LHC nightmare scenario: we find the Higgs and absolutely nothing else which leaves a lot of unanswered questions and no certainty that we will be able to build a machine to find the answers.

Re:Yawn .... wha?!

[Maritz]

Come on, CERN... come up with one good thing.

Obviously you don't consider discovering the Higgs particle a "good thing."

That makes whatever you consider a "good thing" stupidly unrealistic. I daresay CERN would be unconcerned about your criticism. The cheek.