Diphoton bump at LHC leads to generation of hundreds of theoretical papers

Large Hadron Collider
Credit: CERN

(Phys.org)—Last year, two teams working at the LHC reported that they had found proton-to-proton collisions that had led to the creation of more photon pairs (with energies of approximately 750 GeV) than was expected, leading to theories that the evidence might be pointing to a new particle than no one has theorized. This discovery led to a plethora of teams creating papers seeking to be the first to explain this seeming anomaly—so many papers have been submitted to journals for publication that editors have had to pick and choose which to publish. One example is Robert Garisto with Physical Review Letters, who has published an editorial describing the onrush and the decision to publish just four papers in their latest edition, which the editorial team believes is representative of the four main ideas.

In the first , Christoffer Petersson with Chalmers University of Technology in Sweden and Riccardo Torre with Institut de Théorie des Phénomènes Physiques in Switzerland, suggest the bump represents the existence of a boson with very weak interactions that is possibly a supersymmetric partner of the still hypothetical called the goldstino.

In the second paper, the trio Yuichiro Nakai, Ryosuke Sato and Kohsaku Tobioka with affiliations to institutions in the U.S., Israel, and Japan suggest that the bump is evidence of a pion-like boson (a particle made of exotic quarks) which is not currently included in the standard model, and which may be associated with a new type of strong force.

In the third paper a small team from China suggests that the bump can be explained by a Higgs-like boson, one that is six times more massive, that couples to new types of fermions. Garisto notes that this idea or ones similar to it are among the most popular explanations by teams submitting papers to explain the bump.

The fourth paper, by a team of researchers from Korea and the U.S., departs dramatically from the other three and suggests that the increase in is merely evidence of the destruction of a much larger particle and the pairs are just part of the debris field.

The LHC, it might be noted, is in the middle of restarting after a maintenance period, most in the field expect that one of the above theories or perhaps another one altogether will shown to be the true answer as the collider returns to action and starts to offer more and more evidence via future experiments. It has also been noted that it is also still possible that the bump was merely a fluke, and that all the work done to create the papers will prove to have been wasted effort.


Explore further

Physicists offer theories to explain mysterious collision at Large Hadron Collider

More information: Robert Garisto. Editorial: Theorists React to the CERN 750 GeV Diphoton Data, Physical Review Letters (2016). DOI: 10.1103/PhysRevLett.116.150001

Christoffer Petersson et al. 750 GeV Diphoton Excess from the Goldstino Superpartner, Physical Review Letters (2016). DOI: 10.1103/PhysRevLett.116.151804

Yuichiro Nakai et al. Footprints of New Strong Dynamics via Anomaly and the 750 GeV Diphoton, Physical Review Letters (2016). DOI: 10.1103/PhysRevLett.116.151802

Gang Li et al. Pseudoscalar Decaying Only via Loops as an Explanation for the 750 GeV Diphoton Excess, Physical Review Letters (2016). DOI: 10.1103/PhysRevLett.116.151803

Won Sang Cho et al. 750 GeV Diphoton Excess May Not Imply a 750 GeV Resonance, Physical Review Letters (2016). DOI: 10.1103/PhysRevLett.116.151805

Journal information: Physical Review Letters

© 2016 Phys.org

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Apr 21, 2016
What - they think the new particle might be revealed with the existing LHC once it is restarted? I thought for sure they would be asking for a new, even more powerful, collider. Truthfully, this is rather exciting as I had often wondered why photons didn't interact.

Apr 21, 2016
RichManJoe asks
.. rather exciting as I had often wondered why photons didn't interact
Yeah, if I read correctly, article states creation of more photon pairs than expected, it might point to a new particle or it may artifact of instrumentation calibration still going through commissioning so bit too early to tell.

As for photon/photon interaction, photon described well in maxwell's equation & independent of medium, its propagation via tightly coupled electric/magnetic fields effectively causally linked I interpret is closest possible, planck level ? Such that, if 2 photons collide normally pass through each other but, its suggested if energies are very high they might form matter.

I imagine if energies are that high it means frequency is high, that & (closest) conjunction could mean the tight coupling between the electric/magnetic fields of both loses singular coherence favouring the others ie cross-coupled energy as unstable thus decaying to matter.

Apr 21, 2016
I thought for sure they would be asking for a new, even more powerful, collider

Despite the trolls claiming that physicists are just making stuff up for more money to fund bigger experiments, we're realistic about what we can do. Each collider is usually built to service some certain experiments we'd like to understand. And we try to make the most of what we get.

One of LHC's goals is to just collide an awful lot of protons at high energies. What you may not realize is that a proton is a little 'bag' of a lot of particles, each with internal momenta that can add to the overall collision. So for every collision between a nucleon, there is the chance to probe a wide variety of possible collisions/interactions. Hadron colliders like this are good for searching for new stuff, since they have this broad search capacity.

Apr 21, 2016
When we make an electron collider, say, it's only precisely 2 particles colliding. But you can tune those particles to very precise energies and explore certain masses in greater depth.

So while the LHC's broad search helped us find the Higgs, and maybe other stuff, we'd already been planning new electron colliders to do precision experiments of these particles found by the LHC. International Linear Collider (https://en.wikipe...llider), eg.

Interestingly, it's worth noting that since electrons are so light, they don't do well in circular accelerators like LHC (they lose a lot more energy, proportionally, when they make a turn). So that's why it tends to alternate circular hadron collider, linear electron collider. One to explore for new particles, one to do in-depth studies of those particles.

Apr 21, 2016
M_M, no need to invoke Planck lengths or anything like that. First, there's really no such thing as an 'electric' or 'magnetic' field. Observers in relative motion will see what was classically called 'electric' look like 'magnetic' and vice versa. There is only one field, the electromagnetic field, and it has components that correspond to the electric and magnetic parts of classical physics. (If you look at the EM field tensor, a matrix, you'll see some terms are Es and some Bs, the only 'real' thing is the whole tensor * )

Second, photons just don't directly couple. Think about it, EM only deals with charged particles. Photons aren't charged. Therefore photons don't directly interact. They can indirectly interact by transferring momentum to a charged virtual particle/anti-particle pair ** (like electron positron) that allows momentum to pass between them. This is a rare process and is enhanced the closer the photons are to creating a real electron positron pair, (or other pair)

Apr 21, 2016
*: Technically this isn't precisely true either. There are more primative fields that mixed up whenever the Higgs field took on a non-zero vacuum expectation value, and created the fields we call Electromagnetic and Weak. And there may be yet more primitive fields that include the strong force as well, but that's speculative and not really a well crafted theory yet.

**: I don't like talking about virtual particle/anti-particle pairs. People take the term too literally and imagine that there are these real particles that come into existence. It's more like... the maths of quantum mechanics have terms that look like particles, but you can't ever measure directly... so we call them 'virtual' particles, but really they're just a maths factor in how particles move about.

Apr 21, 2016
"most in the field expect that one of the above theories or perhaps another one altogether will shown to be the true answer"

So, if one of the proposed answers is not the answer, then some other answer is the answer. Thanks for telling me nothing!

Apr 21, 2016
If only proton collisions, the only oscillation would be proton to proton to proton. That is, a proton jam. Jeez, making stuff up answers nothing.

Apr 21, 2016
Extremely informative comments SHAVERA.

Thank you for taking the time to post. Most appreciated.

Apr 21, 2016
"most in the field expect that one of the above theories or perhaps another one altogether will shown to be the true answer"

So, if one of the proposed answers is not the answer, then some other answer is the answer. Thanks for telling me nothing!
- Pooua
As long as the funds are forthcoming, there is no reason to stop the quest for THE answer, no matter how long it takes or how costly. Will life continue even without the answer? It most certainly will. But MS scientists need to be kept busy searching.

I do agree with the premise that Mike Massen expounds, namely: "...if 2 photons collide normally pass through each other but, its suggested if energies are very high they might form matter."
The transition from energy to matter with that method is quite logical and is consistent with E=mc2.

Apr 21, 2016
shavera (S) says
M_M, no need to invoke Planck lengths or anything like that
Not invoking as in furthering a proposition, its speculation hence '?' but, if you'd like to pursue a rarefied level consider zero crossing inflection (ZCI) wrt Maxwell's model, whats "anything like that" mean ??

Clarify 'coupling' mentioned in general as ECD claims not directly so to offer consistency in that model offers fermions as mechanism, I consider refinement on Maxwells re fluctuations/variance towards smallest scale on ZCI ie nil reason to avoid planck (like?)

S claims
. no such thing as an 'electric' or 'magnetic' field
At semantic/epistemological level ok but, we're past it re contemporary Physics, why divert to a nebulous semantics/phenomenological arena, what is your objective in this & where do you imagine it leads ?

Please appreciate modeling process re set of definitions. Electric/magnetic useful terms valid empirically by way of relationships, used practically.

Apr 22, 2016
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Apr 22, 2016
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Apr 22, 2016
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Apr 22, 2016
HATE THE ADVERTISEMENTS on the page. I come here for knowledge not for some stupid and irrelevant ad on the page. I know this is how the site makes money but at least limit them OR allow us to take them all off if we would like. The ads are the reason we are running out of band width in general.

Apr 22, 2016
HATE THE ADVERTISEMENTS on the page. I come here for knowledge not for some stupid and irrelevant ad on the page
@neiorah
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Apr 22, 2016
@Piss1
You should report your own comment, as well, since you have decided to quote bschott's comment, thereby continuing the "strong language" for everyone (including kids) to read in this thread. Even if the Mods deleted what bshott has said, YOUR copy of it remains.
Didn't think of that, did you.

Apr 22, 2016
[q
Then there is this completely incorrect statement:

There is only one field, the electromagnetic field,


There is only one field, the magnetic field.

Bulschitt, bschott.
sorry dude, magnetism is relative to particle motion

Apr 22, 2016

You miss the point, of course.
Photons do not directly interact with each other, was the statement.


Well done again my clueless wonder. You added 3 words to his statement that anyone who can read can clearly see aren't there. This one is right up there with stars not being affected by magnetic fields. You need to change your handle to "mindless1" if you are going to keep making stupid statements.

As far as photons not interacting with one another...what is visible light composed of and what happens when it passes through a prism? Why do we need filters to view specific wavelengths? Why are you such a goof?

Actually, the field and the particle are forever linked. The light we see is the field update due to particle motion. Unless you want to suggest that there is an infinite source of photons with no proof, juz say'n

no photons a field that ...

Apr 22, 2016
The above is a search for a Nobel. There is no science there! Science is not this complicated. Time would be better spent with a simulator. Try modeling atoms, compounds, self assembly, etc.. Instead of wasting time and money on nonsense. I'm juz a lawman, not the boss, but if ...

Then define your claim, not a claim before ...

Your boss is an idiot and your investors are fools. Found a bump! jeez, stupid

Apr 22, 2016
@Hyperfuzzy
You are right, twice.

Thanks, I thought no one ever listens to me.

Apr 24, 2016
@Piss1
You should report your own comment, as well, since you have decided to quote bschott's comment, thereby continuing the "strong language" for everyone (including kids) to read in this thread. Even if the Mods deleted what bshott has said, YOUR copy of it remains.
Didn't think of that, did you.


Of course he didn't, he's a moron of the highest order, but at least he keeps on driving that point home....


aaah antigoracle/obama sock sockpuppet biscott (i r baboon) trying his hand at monkeying around in the physics sector: http://i.imgur.com/qWGQyX1.gif

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