Physicists have just detected a very strange particle that is not a particle at all


It sounds like the beginning of a very bad physics enigma: I am a particle that really is not; I vanish before it can be detected, but it can be seen. I break his understanding of physics but I do not check his knowledge. Who I am?

It is a odderon, a particle that is even stranger than its name suggests, and may have been recently detected in the Large Hadron Collider, the most powerful atom destroyer, where particles close at a speed close to that of Light around 17 miles long (27 km) surrounds near Geneva in Switzerland.

It's complicated

First, the odderón is not really a particle. What we consider particles are generally very stable: electrons, protons, quarks, neutrinos, etc. You can hold a bunch of them in your hand and take them with you. Heck, your hand is literally made of them. And your hand will not fade into thin air in the short term, so we can probably safely badume that your fundamental particles will be found in the long term. [7 Strange Facts About Quarks]

There are other particles that do not last long but are still called particles. Despite their short lives, they are still particles. They are free, independent and capable of living by themselves, separated from any interaction: these are the characteristics of a real particle.

And then there is the so-called quasiparticle, which is only one step above not being a particle at all. Quasiparticles are not exactly particles, but they are not exactly fiction either. It's just … complicated. [The 18 Biggest Unsolved Mysteries in Physics]

As in, literally complicated. In particular, the interactions of particles at very high speeds are complicated. When two protons collide with each other almost at the speed of light, they are not like two billiard balls cracking together. It is more like two drops of jellyfish that stagger from one another, become the entrails and everything is arranged before they are again jellyfish on the road.

Feeling quasi

In all this complicated disorder, strange patterns sometimes appear. The tiny particles emerge and disappear in the blink of an eye, only to be followed by another fleeting particle and another. Sometimes these flashes of particles appear in a particular sequence or pattern. Sometimes they are not even flashes of particles, but simply vibrations in the soup of the collision mixture, vibrations that suggest the presence of a transient particle.

This is where physicists face a mathematical dilemma. They may try to fully describe all the complicated disorder that leads to these effervescent patterns, or they may pretend, simply for convenience, that these patterns are "particles" in their own right, but with strange properties, such as negative mbades. and spin that change over time. [5 Seriously Mind-Boggling Math Facts]

Physicists choose the last option, and thus the quasiparticle is born. Quasiparticles are short, effervescent patterns or energy waves that appear in the midst of a collision of high-energy particles. But since it takes a lot of legwork to fully describe that situation mathematically, physicists take some shortcuts and pretend that these patterns are their own particles. It is done only to make mathematics easier to handle. Then, the quasi-particles are treated as particles, although they definitely are not.

It's like pretending that your uncle's jokes are really fun. He is quasifunny purely for convenience.

Take the odds

A particular type of quasiparticle is called the odderon, predicted to exist in the 70s. It is believed to appear when an odd number of quarks, particles of adolescents that are the building blocks of matter, appear briefly in and out of existence during the collisions of protons and antiprotons. If the odderons are present in this rupture scenario, there will be a slight difference in the cross sections (the physical jargon of the ease with which one particle hits the other) of collisions between the particles with each other and with their antiparticles. [Photos: The World’s Largest Atom Smasher (LHC)]

So, if we hit a group of protons together, for example, we can calculate a cross section for that interaction. Then, we can repeat this exercise for proton-antiproton collisions. In a world without odderones, these two cross sections should be identical. But odderones change the image: these brief patterns that we call odderones appear more favorably in particle-particle collisions than antiparticle-antiparticle, which will slightly modify the cross sections.

The problem is that it is predicted that this difference will be very, very small, so it would need a lot of events or collisions before being able to claim a detection.

Now, if we only had a giant particle collider that regularly destroyed protons and antiprotons, and did so with such high energies and so often that we could get reliable statistics. Oh, right: we do, the Large Hadron Collider.

In a recent article, published on March 26 on the arXiv prepress server, the TOTEM Collaboration (in the hilarious jargon of high-energy physics acronym, TOTEM stands for "TOTAL Section, Elastic Dispersion and Diffraction Dissociation Measurement in the LHC "). significant differences between cross sections of protons that destroy other protons versus protons that crash against antiprotons. And the only way to explain the difference is to resurrect this decades-old idea of ​​odderón. There may be other explanations for the data (in other words, other forms of exotic particles), but odderones, strange as they may seem, seem to be the best candidate.

Did TOTEM discover something new and funky about the universe? For sure. TOTEM discovered a new particle? No, because odderones are quasiparticles, not particles in their own right. Does it still help us overcome the limits of known physics? For sure. Does the known physics break? No, because it was predicted that odderones would exist within our current understanding.

Does all that seem a bit strange to you?

Paul M. Sutter he is an astrophysicist in The state university of ohio, great deal of Ask an astronaut Y Space radio, and author of Your place in the universe.

Originally published in Living science.

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