Precise determination of the 𝐵0s–𝐵⎯⎯⎯⎯0s oscillation frequency

Nature Physics. 2022. No. 18. P. 1–5.

Aaij R., Arzymatov K., Belavin V., Boldyrev A., Borisyak M., Derkach D., Hushchyn M., Karpov M., Maevskiy A., Mokhnenko S., Philippov A., Popov S., Ratnikov F., Ryzhikov A., Ustyuzhanin A.

Mesons comprising a beauty quark and strange quark can oscillate between particle (𝐵0sBs0) and antiparticle (𝐵⎯⎯⎯⎯0sB¯s0) flavour eigenstates, with a frequency given by the mass difference between heavy and light mass eigenstates, Δms. Here we present a measurement of Δms using 𝐵0s→𝐷−sBs0→Ds−π+ decays produced in proton–proton collisions collected with the LHCb detector at the Large Hadron Collider. The oscillation frequency is found to be Δms = 17.7683 ± 0.0051 ± 0.0032 ps−1, where the first uncertainty is statistical and the second is systematic. This measurement improves on the current Δms precision by a factor of two. We combine this result with previous LHCb measurements to determine Δms = 17.7656 ± 0.0057 ps−1, which is the legacy measurement of the original LHCb detector.

Keywords: анализ данных, data analysis, high energy, физика высоких

Publication based on the results of: Machine learning to check and improve the quality of data collected at the Large Hadron Collider and other particle physics experiments (2022)