%0 Journal Article %T Observation of the B0s → D*+ D*- decay %A LHCb Collaboration (Aaij, R. et al %A Jaimes Elles, S. J. %A Jashal, B. K. %A Martinez-Vidal, F. %A Oyanguren, A. %A Rebollo De Miguel, M. %A Remon Alepuz, C. %A Ruiz Vidal, J. %A Sanderswood, I. %J Journal of High Energy Physics %D 2023 %V 07 %N 7 %I Springer %@ 1029-8479 %G English %F LHCbCollaborationAaij_etal2023 %O WOS:001061773900001 %O exported from refbase (https://references.ific.uv.es/refbase/show.php?record=5741), last updated on Wed, 10 Apr 2024 12:41:02 +0000 %X The first observation of the B-s(0) -> D*+ D*- decay and the measurement of its branching ratio relative to the B-0 -> D*+ D*(-) decay are presented. The data sample used corresponds to an integrated luminosity of 9 fb(-1) of proton-proton collisions recorded by the LHCb experiment at centre-of-mass energies of 7, 8 and 13 TeV between 2011 and 2018. The decay is observed with more than 10 standard deviations and the time-integrated ratio of branching fractions is determined to be [GRAPHICS] . where the first uncertainty is statistical, the second systematic and the third due to the uncertainty of the fragmentation fraction ratio f(s)/f(d). The B-s(0) -> D*(+) D*(-) branching fraction is calculated to be [GRAPHICS] . where the fourth uncertainty is due to the B-0 -> D*(+) D*(-) branching fraction. These results are calculated using the average B-s(0) meson lifetime in simulation. Correction factors are reported for scenarios where either a purely heavy or a purely light B-s(0) eigenstate is considered. %K Branching fraction %K Hadron-Hadron Scattering %R 10.1007/JHEP07(2023)119 %U https://arxiv.org/abs/2210.14945 %U https://doi.org/10.1007/JHEP07(2023)119 %P 119-19pp