Scientists from the Fermi Laboratory (Chicago, USA) have presented theresults of a data analysis obtained on the CDF detectorOf the acceleratorTevatron that, if validated, would reveal the existence ofa “new physics” different from the Standard Model, the theory that describes the fundamental particles and their interactions. Depending on the interpretations, it could bea Higgs boson other than the one proposed by the theory, or another particle carrying a new force. The results will be published in the journalPhysical Review Letters.
The researchers analyzed a select sample of data from 10,000 proton-antiproton collisions recorded in the CDF detector of the Tevatron accelerator, which will close in September this year after two decades of operation due to no extra funding from the US government. The sample selected collisions with two jets of hadronic particles and a W particle decaying into lepton particles (electron or muon and their corresponding neutrinos). W is one of the weak interaction carrier particles, one of the four fundamental forces of nature together with the strong interaction, electromagnetic and gravity.
In the study of the invariant mass of the two jets produced, the CDF scientists found an excess of energy in about 250 cases compared to what was expected, around 144 gigaelectronvolts (GeV). This excess with respect to the predictions of the Standard Model could indicate the result of the disintegration of a new particle with a mass between 120 and 160 GeV (120 to 160 times heavier than a proton). One possible explanation would be evidence of an unexpected new version of the Higgs boson, the particle that according to the Standard Model would give mass to the rest. Another, that it is a particle carrying a new force that would operate at the subatomic level and would be added to the four already existing.
The results obtained by the CDF collaboration have surprised the international scientific community, since, if proven true, they would mean the discovery of a new particle beyond the Standard Model. But at the moment the result has a confidence level of three sigmas, insufficient to be considered a “true” discovery.
For Alberto Ruiz Jimeno, from the Institute of Physics of Cantabria, “this result, along with some other recent ones, showsanomalies with the standard model that could be a sign of new physics, although it could also be due to statistical fluctuations or modeling defects. “According to the Spanish researcher, the CDF results” open a storm of activity, both on the part of theoretical and experimental physicists. “Specifically, Ruiz Jimeno trusts in that “the LHC data will be able to confirm or reject this effect shortly.”
