Test of lepton universality with $B^0 \rightarrow K^*0\ell^+\ell^-$ decaysстатья
Статья опубликована в высокорейтинговом журнале
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Статья опубликована в журнале из списка Web of Science и/или Scopus
Дата последнего поиска статьи во внешних источниках: 16 ноября 2017 г.
Аннотация: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∗0 meson is reconstructed in the final state K+π−, which is required to have an invariant mass within 100MeVc2 of the known K∗(892)0 mass. The analysis is performed using proton-proton collision data, corresponding to an integrated luminosity of about 3fb−1, collected by the LHCb experiment at centre-of-mass energies of 7 and 8TeV. The ratio is measured in two regions of the dilepton invariant mass squared, q2, to be
RK∗0={0.66+0.11−0.07(stat)±0.03(syst)0.69+0.11−0.07(stat)±0.05(syst)for 0.045<q2<1.1GeV2c4,for 1.1<q2<6.0GeV2c4.
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 in the two q2 regions, respectively.