Measurement of the CKM angle γ in B± → DK± and B± → Dπ± decays with D → 𝐾0Sh+h−

Journal of High Energy Physics. 2021. Vol. 2021. No. 2. Article 169.

Aaij R., Beteta C. A., Arzymatov K., Belavin V., Boldyrev A., Borisyak M., Derkach D., Гайнцева Т. А., Hushchyn M., Kazeev N., Maevskiy A., Филиппов А. А., Popov S., Ratnikov F., Ryzhikov A., Ustyuzhanin A., LHCb C.

A measurement of CP-violating observables is performed using the decays B± → DK± and B± → Dπ±, where the D meson is reconstructed in one of the self-conjugate three-body final states 𝐾0SKS0π+π− and 𝐾0SKS0K+K− (commonly denoted 𝐾0SKS0h+h−). The decays are analysed in bins of the D-decay phase space, leading to a measurement that is independent of the modelling of the D-decay amplitude. The observables are inter- preted in terms of the CKM angle γ. Using a data sample corresponding to an integrated luminosity of 9 fb−1 collected in proton-proton collisions at centre-of mass energies of 7, 8, and 13 TeV with the LHCb experiment, γ is measured to be (68.7+5.2−5.1)∘(68.7−5.1+5.2)∘. The hadronic parameters 𝑟𝐷𝐾𝐵,𝑟𝐷𝜋𝐵,𝛿𝐷𝐾𝐵,and𝛿𝐷𝜋𝐵rBDK,rBDπ,δBDK,andδBDπ, which are the ratios and strong-phase differences of the suppressed and favoured B± decays, are also reported.

Keywords: физика высоких энергий, Experimental High Energy Physics and Elementary Particles Physics

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 (2021)