Physicists spot rare three-boson collision, opening new window on particle physics
Researchers at CERN have detected a fleeting interaction between three fundamental particles—a finding that could reveal new physics beyond current theory. The discovery constrains hypothetical particles and forces that might explain mysteries like dark matter, potentially reshaping our understanding of the universe's building blocks.
Originaltitel: Observation of 𝑊𝑍𝛾 production and constraints on new physics scenarios in proton-proton collisions at √𝑠 =13 TeV
<p>A measurement of the 𝑊𝑍𝛾 triboson production cross section is presented. The analysis is based on a data sample of proton-proton collisions at a center-of-mass energy of √𝑠 =13 TeV recorded with the CMS detector at the LHC, corresponding to an integrated luminosity of 138 fb<sup>−1</sup>. The analysis focuses on the final state with three charged leptons, ℓ<sup>±</sup>𝜈ℓ<sup>+</sup>ℓ<sup>−</sup>, where ℓ =𝑒 or 𝜇, accompanied by an additional photon. The observed (expected) significance of the 𝑊𝑍𝛾 signal is 5.4 (3.8) standard deviations. The cross section is measured in a fiducial region, where events with an ℓ originating from a tau lepton decay are excluded, to be 5.48 ±1.11 fb, which is compatible with the prediction of 3.69 ±0.24 fb at next-to-leading order in quantum chromodynamics. Exclusion limits are set on anomalous quartic gauge couplings and on the production cross sections of massive axionlike particles.</p>