Research output: Contribution to journal › Article › peer-review
Strong constraints on the b → sγ photon polarisation from B 0 → K *0 e + e − decays. / The LHCb Collaboration.
In: Journal of High Energy Physics, Vol. 2020, No. 12, 81, 12.2020.Research output: Contribution to journal › Article › peer-review
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TY - JOUR
T1 - Strong constraints on the b → sγ photon polarisation from B 0 → K *0 e + e − decays
AU - The LHCb Collaboration
AU - Aaij, R.
AU - Abellán Beteta, C.
AU - Ackernley, T.
AU - Adeva, B.
AU - Adinolfi, M.
AU - Afsharnia, H.
AU - Aidala, C. A.
AU - Aiola, S.
AU - Ajaltouni, Z.
AU - Akar, S.
AU - Albrecht, J.
AU - Alessio, F.
AU - Alexander, M.
AU - Alfonso Albero, A.
AU - Aliouche, Z.
AU - Alkhazov, G.
AU - Alvarez Cartelle, P.
AU - Amato, S.
AU - Amhis, Y.
AU - An, L.
AU - Anderlini, L.
AU - Andreianov, A.
AU - Andreotti, M.
AU - Archilli, F.
AU - Artamonov, A.
AU - Artuso, M.
AU - Arzymatov, K.
AU - Aslanides, E.
AU - Atzeni, M.
AU - Audurier, B.
AU - Bachmann, S.
AU - Bachmayer, M.
AU - Back, J. J.
AU - Baker, S.
AU - Baladron Rodriguez, P.
AU - Balagura, V.
AU - Baldini, W.
AU - Baptista Leite, J.
AU - Barlow, R. J.
AU - Barsuk, S.
AU - Barter, W.
AU - Bartolini, M.
AU - Baryshnikov, F.
AU - Bondar, A.
AU - Eidelman, S.
AU - Krokovny, P.
AU - Kudryavtsev, V.
AU - Maltsev, T.
AU - Shekhtman, L.
AU - Vorobyev, V.
N1 - Publisher Copyright: © 2020, The Author(s). Copyright: Copyright 2020 Elsevier B.V., All rights reserved.
PY - 2020/12
Y1 - 2020/12
N2 - An angular analysis of the B0 → K*0e+e− decay is performed using a data sample corresponding to an integrated luminosity of 9 fb−1 of pp collisions collected with the LHCb experiment. The analysis is conducted in the very low dielectron mass squared (q2) interval between 0.0008 and 0.257 GeV2, where the rate is dominated by the B0 → K*0γ transition with a virtual photon. The fraction of longitudinal polarisation of the K*0 meson, FL, is measured to be FL = (4.4 ± 2.6 ± 1.4)%, where the first uncertainty is statistical and the second systematic. The ATRe observable, which is related to the lepton forward-backward asymmetry, is measured to be ATRe = −0.06 ± 0.08 ± 0.02. The AT(2) and ATIm transverse asymmetries, which are sensitive to the virtual photon polarisation, are found to be AT(2) = 0.11 ± 0.10 ± 0.02 and ATIm = 0.02 ± 0.10 ± 0.01. The results are consistent with Standard Model predictions and provide the world’s best constraint on the b → sγ photon polarisation.
AB - An angular analysis of the B0 → K*0e+e− decay is performed using a data sample corresponding to an integrated luminosity of 9 fb−1 of pp collisions collected with the LHCb experiment. The analysis is conducted in the very low dielectron mass squared (q2) interval between 0.0008 and 0.257 GeV2, where the rate is dominated by the B0 → K*0γ transition with a virtual photon. The fraction of longitudinal polarisation of the K*0 meson, FL, is measured to be FL = (4.4 ± 2.6 ± 1.4)%, where the first uncertainty is statistical and the second systematic. The ATRe observable, which is related to the lepton forward-backward asymmetry, is measured to be ATRe = −0.06 ± 0.08 ± 0.02. The AT(2) and ATIm transverse asymmetries, which are sensitive to the virtual photon polarisation, are found to be AT(2) = 0.11 ± 0.10 ± 0.02 and ATIm = 0.02 ± 0.10 ± 0.01. The results are consistent with Standard Model predictions and provide the world’s best constraint on the b → sγ photon polarisation.
KW - B physics
KW - Flavour Changing Neutral Currents
KW - Hadron-Hadron scattering (experiments)
KW - Polarization
KW - Rare decay
KW - ASYMMETRIES
UR - http://www.scopus.com/inward/record.url?scp=85097537572&partnerID=8YFLogxK
U2 - 10.1007/JHEP12(2020)081
DO - 10.1007/JHEP12(2020)081
M3 - Article
AN - SCOPUS:85097537572
VL - 2020
JO - Journal of High Energy Physics
JF - Journal of High Energy Physics
SN - 1029-8479
IS - 12
M1 - 81
ER -
ID: 27070367