%0 Journal Article
%T Angular analysis of B0 -> D*- D*s+ with D*s+ -> Ds + gamma decays
%A LHCb Collaboration (Aaij, R. et al
%A Henry, L.
%A Jashal, B. K.
%A Martinez-Vidal, F.
%A Oyanguren, A.
%A Remon Alepuz, C.
%A Ruiz Vidal, J.
%J Journal of High Energy Physics
%D 2021
%V 06
%N 6
%I Springer
%@ 1029-8479
%G English
%F LHCbCollaborationAaij_etal2021
%O WOS:000671168600002
%O exported from refbase (https://references.ific.uv.es/refbase/show.php?record=4890), last updated on Wed, 11 Aug 2021 09:27:56 +0000
%X The first full angular analysis of the B0 -> D-Ds+ decay is performed using 6 fb(-1) of pp collision data collected with the LHCb experiment at a centre-of-mass energy of 13 TeV. The Ds+-> Ds+gamma and D*- -> D<overbar></mml:mover>0- vector meson decays are used with the subsequent Ds+ -> K+K-pi (+) and D<overbar></mml:mover>0 -> K+pi (-) decays. All helicity amplitudes and phases are measured, and the longitudinal polarisation fraction is determined to be f(L) = 0.578 +/- 0.010 +/- 0.011 with world-best precision, where the first uncertainty is statistical and the second is systematic. The pattern of helicity amplitude magnitudes is found to align with expectations from quark-helicity conservation in B decays. The ratio of branching fractions [B(B0 -> D-Ds+) x B(Ds+-> Ds+gamma)]/B(B-0 -> D(*-)Ds+) is measured to be 2.045 +/- 0.022 +/- 0.071 with world-best precision. In addition, the first observation of the Cabibbo-suppressed B-s -> D(*-)Ds+ decay is made with a significance of seven standard deviations. The branching fraction ratio B(B-s -> D(*-)Ds<mml:mo>+)/B(B-0 -> D(*-)Ds<mml:mo>+) is measured to be 0.049 +/- 0.006 +/- 0.003 +/- 0.002, where the third uncertainty is due to limited knowledge of the ratio of fragmentation fractions.<fig id="Figa" position="anchor"><graphic position="anchor" specific-use="HTML" mime-subtype="JPEG" xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="MediaObjects/13130_2021_16089_Figa_HTML.jpg" id="MO1"></graphic
%K B physics
%K Branching fraction
%K Hadron-Hadron scattering (experiments)
%K Polarization
%R 10.1007/JHEP06(2021)177
%U https://arxiv.org/abs/2105.02596
%U https://doi.org/10.1007/JHEP06(2021)177
%P 177-30pp