%0 Journal Article
%T Observation of Photon Polarization in the b -> s gamma Transition
%A LHCb Collaboration (Aaij, R. et al
%A Martinez-Vidal, F.
%A Oyanguren, A.
%A Ruiz Valls, P.
%J Physical Review Letters
%D 2014
%V 112
%N 16
%I Amer Physical Soc
%@ 0031-9007
%G English
%F LHCbCollaborationAaij_etal2014
%O WOS:000338513000004
%O exported from refbase (https://references.ific.uv.es/refbase/show.php?record=1839), last updated on Mon, 22 Sep 2014 13:07:41 +0000
%X This Letter presents a study of the flavor-changing neutral current radiative B-+/- -> K-+/-pi(-/+)pi(+/-)gamma decays performed using data collected in proton-proton collisions with the LHCb detector at 7 and 8 TeV center-of-mass energies. In this sample, corresponding to an integrated luminosity of 3 fb(-1), nearly 14 000 signal events are reconstructed and selected, containing all possible intermediate resonances with a K-+/-pi(-/+)pi(+/-) final state in the [1.1, 1.9] GeV/c(2) mass range. The distribution of the angle of the photon direction with respect to the plane defined by the final-state hadrons in their rest frame is studied in intervals of K-+/-pi(-/+)pi(+/-) mass and the asymmetry between the number of signal events found on each side of the plane is obtained. The first direct observation of the photon polarization in the b -> s(gamma) transition is reported with a significance of 5.2 sigma.
%R 10.1103/PhysRevLett.112.161801
%U http://arxiv.org/abs/1402.6852
%U https://doi.org/10.1103/PhysRevLett.112.161801
%P 161801-8pp