An angular analysis of the B0 → K*0 e+ e− decay is performed using a data sample, corresponding to an integrated luminosity of 3.0 fb^−1, collected by the LHCb experiment in pp collisions at centre-of-mass energies of 7 and 8 TeV during 2011 and 2012. For the first time several observables are measured in the dielectron mass squared (q^2) interval between 0.002 and 1.120 GeV^2/c^4. The angular observables F_L and A_T^Re which are related to the K*0 polarisation and to the lepton forward-backward asymmetry, are measured to be F_L = 0.16 ± 0.06 ± 0.03 and A_T^Re = 0.10 ± 0.18 ± 0.05, where the first uncertainty is statistical and the second systematic. The angular observables A_T^(2) and A_T^Im which are sensitive to the photon polarisation in this q^2 range, are found to be A_T^(2) = − 0.23 ± 0.23 ± 0.05 and A_T^Im = 0.14 ± 0.22 ± 0.05. The results are consistent with Standard Model predictions.
Angular Analysis of the B0 → K*0 e+ e− Decay in the Low-q^2 Region
L. Capriotti;CARBONE, ANGELO;GALLI, DOMENICO;MOGGI, NICCOLO';MUSSINI, MANUEL;PATRIGNANI, CLAUDIA;PERAZZINI, STEFANO;VAGNONI, VINCENZO MARIA;ZANGOLI, MARIA;
2015
Abstract
An angular analysis of the B0 → K*0 e+ e− decay is performed using a data sample, corresponding to an integrated luminosity of 3.0 fb^−1, collected by the LHCb experiment in pp collisions at centre-of-mass energies of 7 and 8 TeV during 2011 and 2012. For the first time several observables are measured in the dielectron mass squared (q^2) interval between 0.002 and 1.120 GeV^2/c^4. The angular observables F_L and A_T^Re which are related to the K*0 polarisation and to the lepton forward-backward asymmetry, are measured to be F_L = 0.16 ± 0.06 ± 0.03 and A_T^Re = 0.10 ± 0.18 ± 0.05, where the first uncertainty is statistical and the second systematic. The angular observables A_T^(2) and A_T^Im which are sensitive to the photon polarisation in this q^2 range, are found to be A_T^(2) = − 0.23 ± 0.23 ± 0.05 and A_T^Im = 0.14 ± 0.22 ± 0.05. The results are consistent with Standard Model predictions.File | Dimensione | Formato | |
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2015-AR-15-Ang_An_of_the_B0_to_Kstar0_ep_em_Dec_in_the_Low-q2_Region-JHEP.pdf
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