Observation of CP violation in two-body B s 0 $$ {B}_{(s)}^0 $$ -meson decays to charged pions and kaons

Abstract The time-dependent CP asymmetries of B0 → π+π− and B s 0...

Full description

Bibliographic Details
Main Authors: Aaij, R., Abellán Beteta, C., Ackernley, T., Adeva, B., Adinolfi, M., Afsharnia, H., Aidala, C. A., Aiola, S., Ajaltouni, Z., Akar, S., Albrecht, J., Alessio, F., Alexander, M., Alfonso Albero, A., Aliouche, Z.
Other Authors: Massachusetts Institute of Technology. Department of Physics
Format: Article
Language:English
Published: Springer Berlin Heidelberg 2021
Online Access:https://hdl.handle.net/1721.1/132052
Description
Summary:Abstract The time-dependent CP asymmetries of B0 → π+π− and B s 0 $$ {B}_s^0 $$ → K+K− decays are measured using a data sample of pp collisions corresponding to an integrated luminosity of 1.9 fb−1, collected with the LHCb detector at a centre-of-mass energy of 13 TeV. The results are C ππ = − 0.311 ± 0.045 ± 0.015 , S ππ = − 0.706 ± 0.042 ± 0.013 , C KK = 0.123 ± 0.034 ± 0.015 , S KK = 0.164 ± 0.034 ± 0.014 , A KK Δ Γ = − 0.83 ± 0.05 ± 0.09 , $$ {\displaystyle \begin{array}{c}{C}_{\pi \pi}=-0.311\pm 0.045\pm 0.015,\\ {}{S}_{\pi \pi}=-0.706\pm 0.042\pm 0.013,\\ {}{C}_{KK}=0.123\pm 0.034\pm 0.015,\\ {}{S}_{KK}=0.164\pm 0.034\pm 0.014,\\ {}{\mathcal{A}}_{KK}^{\Delta \varGamma }=-0.83\pm 0.05\pm 0.09,\end{array}} $$ where the first uncertainties are statistical and the second systematic. The same data sample is used to measure the time-integrated CP asymmetries of B0 → K + π− and B s 0 $$ {B}_s^0 $$ → K−π+ decays and the results are A CP B 0 = − 0.0824 ± 0.0033 ± 0.0033 , A CP B s 0 = 0.236 ± 0.013 ± 0.011 . $$ {\displaystyle \begin{array}{c}{A}_{CP}^{B^0}=-0.0824\pm 0.0033\pm 0.0033,\\ {}{A}_{CP}^{B_s^0}=0.236\pm 0.013\pm 0.011.\end{array}} $$ All results are consistent with earlier measurements. A combination of LHCb measurements provides the first observation of time-dependent CP violation in B s 0 $$ {B}_s^0 $$ decays.