A test of lepton universality, performed by measuring the ratio of the branching fractions of the B0 → K∗0µ+µ− and B0 → K∗0e+e− decays, RK∗0 , is presented. The K∗0meson is reconstructed in the final state K+π−, which is required to have an invariant mass within 100 MeV/c2 of the known K∗(892)0 mass. The analysis is performed using proton-proton collision data, corresponding to an integrated luminosity of about 3 fb−1, collected by the LHCb experiment at centre-of-mass energies of 7 and 8 TeV. The ratio is measured in two regions of the dilepton invariant mass squared, q2, to beRK∗0 =(0.66 + 0.11− 0.07 (stat) ± 0.03 (syst) for 0.045 < q2 < 1.1 GeV2/c4,0.69 + 0.11− 0.07 (stat) ± 0.05 (syst) for 1.1 < q2 < 6.0 GeV2/c4.The corresponding 95.4% confidence level intervals are [0.52, 0.89] and [0.53, 0.94]. The results, which represent the most precise measurements of RK∗0 to date, are compatible with the Standard Model expectations at the level of 2.1–2.3 and 2.4–2.5 standard deviations inthe two q2regions, respectively

Test of lepton universality with B0→ K*0ℓ+ℓ−decays / The LHCb, C., Aaij, R., Adeva, B., Adinolfi, M., Ajaltouni, Z., Akar, S., Albrecht, J., Alessio, F., Alexander, M., Ali, S., Alkhazov, G., Alvarez Cartelle, P., Alves, A.A., Amato, S., Amerio, S., Amhis, Y., An, L., Anderlini, L., Andreassi, G., Andreotti, M., et al.. - In: JOURNAL OF HIGH ENERGY PHYSICS. - ISSN 1029-8479. - 2017:8(2017). [10.1007/JHEP08(2017)055]

Test of lepton universality with B0→ K*0ℓ+ℓ−decays

Capriotti, L.;Casse, G.;Sarti, A.;Sciubba, A.;
2017

Abstract

A test of lepton universality, performed by measuring the ratio of the branching fractions of the B0 → K∗0µ+µ− and B0 → K∗0e+e− decays, RK∗0 , is presented. The K∗0meson is reconstructed in the final state K+π−, which is required to have an invariant mass within 100 MeV/c2 of the known K∗(892)0 mass. The analysis is performed using proton-proton collision data, corresponding to an integrated luminosity of about 3 fb−1, collected by the LHCb experiment at centre-of-mass energies of 7 and 8 TeV. The ratio is measured in two regions of the dilepton invariant mass squared, q2, to beRK∗0 =(0.66 + 0.11− 0.07 (stat) ± 0.03 (syst) for 0.045 < q2 < 1.1 GeV2/c4,0.69 + 0.11− 0.07 (stat) ± 0.05 (syst) for 1.1 < q2 < 6.0 GeV2/c4.The corresponding 95.4% confidence level intervals are [0.52, 0.89] and [0.53, 0.94]. The results, which represent the most precise measurements of RK∗0 to date, are compatible with the Standard Model expectations at the level of 2.1–2.3 and 2.4–2.5 standard deviations inthe two q2regions, respectively
2017
B physics, Branching fraction, Hadron-Hadron scattering (experiments), Rare decay
01 Pubblicazione su rivista::01a Articolo in rivista
Test of lepton universality with B0→ K*0ℓ+ℓ−decays / The LHCb, C., Aaij, R., Adeva, B., Adinolfi, M., Ajaltouni, Z., Akar, S., Albrecht, J., Alessio, F., Alexander, M., Ali, S., Alkhazov, G., Alvarez Cartelle, P., Alves, A.A., Amato, S., Amerio, S., Amhis, Y., An, L., Anderlini, L., Andreassi, G., Andreotti, M., et al.. - In: JOURNAL OF HIGH ENERGY PHYSICS. - ISSN 1029-8479. - 2017:8(2017). [10.1007/JHEP08(2017)055]
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11573/1074646
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