The Large Hadron Collider (LHC), a huge accelerator of elementary particles, continues to push the boundaries of science, and within the framework of the latest experiments with its participation, scientists have discovered something that can be the first potential evidence of the existence of a subatomic quasiparticle, called an odderon, which previously existed only in theory . The obtained results affect hadrons, a family of elementary particles, which includes protons and neutrons, which consist of quarks “glued together” with the help of gluons.
In their experiments with the LHC, scientists used a special operating mode of the accelerator, in which colliding protons remain intact, and do not collapse, giving rise to whole showers of secondary particles. Earlier, in carrying out similar experiments, it was noted that in such collisions, protons do not simply fly off from each other, they manage to exchange very few gluons very quickly. At the same time, the number of “exchange” gluons was always even before.
The scientists did not find out the odderon itself, but the researchers observed certain effects that could indicate its presence. Physicists used protons with high energy, which allowed them to obtain greater accuracy of the measurements. And in the results of these measurements, cases of exchange between protons of an odd number of gluons were found, which does not fit into all existing models of similar processes. The researchers believe that the responsibility for this discrepancy is precisely the odderon, a quasiparticle consisting in this case of three, five, seven and more odd number of gluons, which is formed for a short time at the moment of proton collision.
“The results do not break the existing Standard Model of Elementary Particle Physics. In this model, there are a number of “dark places”, and our work has allowed to “highlight” only one of these areas and add another new detail to it, “says Timothy Raben, a specialist in elementary and sub-elementary particle physics from Kansas University.
For the searches, high-sensitivity TOTEM sensors were used, installed at four key points of the collider tunnel, where proton beams intersect and billions of collisions occur every second.
“One of the possible explanations of why protons can collide without destruction is the odderon, but in practice scientists have never seen it. This may be the first case of obtaining a real proof of the existence of these quasiparticles, “commented Simona Giani, representative of a group of physicists working with the TOTEM experiment, which is part of the general work on quasiparticle search.
Understand this layman is quite difficult, so scientists explain this with the example of an auto transporting cars in a trailer.
“Imagine that protons are two big tractors carrying cars. These are often found on the road, “explains Raben.
“Now imagine that these two trucks collide with one another, but after the accident the trucks remain intact, but the cars they transported will fly apart in different directions. And in this case, literally in the air, new machines are formed. Energy goes into a state of matter. “
“Physicists hunt for theoretical odderons for the past few decades, since the 1970s. However, the technological capabilities of that time simply did not allow us to obtain evidence of the existence of odderons, “adds Raben.
More than 100 scientists from eight countries were involved in the experiments on searching for odderons. Bundles of proton pairs were dispersed inside the LHC every second. Thanks to the modernization of the hadronic collider in 2015, the peak energy level of the accelerated protons was 13 TeV.
Despite the fact that the researchers could not directly observe the odderon, they witnessed its effects and in the future hope to get more transparent results. Scientists believe that the next upgrade of the LHC will allow them to be obtained, which will allow dispersing the particles to even higher energy indices.
“We expect great results in the next few years,” commented Christoph Royon of Kansas University.
The results of the current work were published on the ArXiv.org website and are currently awaiting evaluation by other specialists.