The European Center for Particle Physics (CERN) has announced the discovery of odderon, a rare combination of three fundamental particles called gluons that had been theorized almost half a century ago but, until now, could not be identified in real conditions.
The strangest and most elusive particle
Proving its existence has been a great experimental challenge for scientists because, although the arrival of quantum chromodynamics made it possible to predict the existence of the odderon (it was two French physicists back in 1973 ; which led to the opening of an international ‘hunt’ for particles). The very detailed measurements of protons as they deflect from each other in high-energy collisions have been the most difficult, albeit unsuccessful.
The states that comprise two, three or more gluons are peculiar objects made only of the carriers of the strong force. While most high-energy collisions cause protons to break apart into their constituent quarks and gluons, about 25% are elastic collisions where the protons remain intact but emerge via slightly different paths.
Thus, the Odderon particle is what is briefly formed when protons collide in high-energy collisions and, in some cases, do not break apart, but bounce off each other and scatter. Protons are made up of quarks and gluons, which briefly form Odderon and Pomeron particles. Now, we have managed to identify the Odderon. A milestone in particle physics and a further step in understanding matter, the fundamental building blocks of our world.
The physicists compared the pp̄ data from the LHC (recorded at collision energies of 2.76, 7, 8, and 13 TeV and extrapolated to 1.96 TeV) with the pp̄ data from Tevatron measured at 1.96 TeV.
Through extensive analysis of proton-proton and proton-antiproton elastic collision data, the researchers were able to focus on the new particle. The analysis, the fruit of hard work with some of the best particle physicists on the planet, took several months, but ultimately paid off.
” Our result probes the deeper features of quantum chromodynamics, in particular that gluons interact with each other and that an odd number of gluons can be ‘colorless’, thus protecting the strong interaction, ” says Simone Giani, CERN physicist and spokesperson. of TOTEM ( Total Cross Section, Elastic Scattering and Diffraction Dissociation , which measures the total effective section pp and studies the elastic and diffractive dispersion at the LHC), a collaboration in which some 80 physicists from 11 universities participate.
“A notable feature of this work is that the results are produced by joining the LHC and Tevatron data at different energies,” continues the expert, whose research results have been collected by The European Physical Journal C.
What does odderon mean?
His baptism is quite transparent. Odderon comes from the English, “odder” , which means “the strangest” , not for nothing is one of the rarest particles predicted by physics.
Referencia: T. Csörgő et al. Evidence of Odderon-exchange from scaling properties of elastic scattering at TeV energies, The European Physical Journal C (2021). DOI: 10.1140/epjc/s10052-021-08867-6
