The LHCb detector at the Large Hadron Collider (LHC) has made a breakthrough in particle physics — for the first time ever, it has measured the mass of the Z boson with a precision that was previously only possible in an electron-positron collider. This is not simply a refinement of one of the fundamental constants, but a significant step toward a deeper understanding of the Universe.
During the research, more than 170,000 Z boson decays into muon pairs were analyzed. As a result, the mass of the boson was determined to be 91,184.2 MeV with an error of less than 0.01%. The value obtained is in perfect agreement with the Standard Model theory — the most accurate physical theory describing the interaction of all known elementary particles.
This has far-reaching consequences for space science. The Z boson plays a key role in weak nuclear interactions, which influence the early evolution of the Universe, the distribution of energy in the microwave background, and the number of neutrinos in space. Any deviation from the expected mass could indicate new physics — for example, dark matter particles.
The work of LHCb proves that even under the complex conditions of proton-proton collisions at the LHC, it is possible to achieve a level of precision that was previously considered unattainable. This opens the way to new research — not only in particle physics, but also in cosmology and astronomy.
For astronomy and space research, the exact “weight” of the Z boson is a kind of calibration point for the entire Standard Model, which astronomers use in computer simulations of the evolution of the early Universe, calculations of neutrino concentration, and research into weak interactions in stellar nucleosynthesis processes. Correct values for this constant help to compare data from space observatories (CMB telescopes, cosmic ray detectors, and gravitational wave detectors) with theoretical predictions, eliminating systematic errors. Thus, the LHCb measurement provides a “baseline” that can be used to model the structure of the Universe more accurately, refine the parameters of dark matter, and search for physics beyond current theories.
Discoveries such as this measurement of the Z boson help to unravel the origin of particles in space. Read our special article, “How are high-energy particles born in the Universe?” There, we explain how cosmic rays of extreme energies are accelerated and what astrophysical “accelerators” are behind this process.
