Journal Article

Test of lepton universality withB⁰ → K⁰ℓ⁺ℓ⁻decays

Blouw, J., Blusk, S., Bettler, M.-O., Blake, T., Britton, T., Appleby, R.B., Braun, S., Barsuk, S., Baszczyk, M., Alexander, M., Ajaltouni, Z., Aaij, R., Anderlini, L., Bordyuzhin, I., Andreassi, G., Burr, C., Balagura, V., Boettcher, T., Alkhazov, G., Battista, V., Baesso, C., Bedeschi, F., Belous, K., Baker, S., Birnkraut, A., Borysova, M., Bonivento, W., Adeva, B., Baryshnikov, F., Bencivenni, G., Buchanan, E., Bondar, N., Bifani, S., Badalov, A., Bozzi, C., Barter, W., Blanc, F., Adinolfi, M., Aslanides, E., Borisyak, M., Andreotti, M., Betti, F., Akar, S., Bezshyiko, Ia, Albrecht, J., Billoir, P., Babuschkin, I., Amhis, Y., Belloli, N., Belyaev, I., Beaucourt, L., Bellee, V., Baldini, W., Beuzekom, M., Barschel, C., Amerio, S., Berezhnoy, A., Borgheresi, A., Andrews, J.E., Bocci, V., Bowen, E., Bachmann, S., Brodzicka, J., Back, J.J., Artuso, M., Beiter, A., Bernet, R., Borsato, M., An, L., Ali, S., Auriemma, G., Artamonov, A., Bel, L.J., Boubdir, M., Archilli, F., Berninghoff, D., Beddow, J., Bediaga, I., d'Argent, P., Batozskaya, V., Borghi, S., Baranov, A., Baalouch, M., Betancourt, C., Beranek, S., Bossu, F., Alves, A.A., Bitadze, A., Barlow, R.J., Be

2017

Overview

A test of lepton universality, performed by measuring the ratio of the branching fractions of the B $^{0}$→ K $^{*0}$μ $^{+}$μ $^{−}$and B $^{0}$→ K $^{*0}$e $^{+}$e $^{−}$decays,$ {R}_{K^{*0}} $, is presented. The K $^{*0}$meson is reconstructed in the final state K $^{+}$π $^{−}$ , which is required to have an invariant mass within 100 MeV/c $^{2}$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, q $^{2}$ , to be$ {R}_{K^{*0}}=\\left\\{\\begin{array}{l}{0.66_{-}^{+}}_{0.07}^{0.11}\\left(\\mathrm{stat}\\right)\\pm 0.03\\left(\\mathrm{syst}\\right)\\kern1em \\mathrm{f}\\mathrm{o}\\mathrm{r}\\kern1em 0.045<{q}^2<1.1\\kern0.5em {\\mathrm{GeV}}^2/{c}^4,\\hfill \\\ {}{0.69_{-}^{+}}_{0.07}^{0.11}\\left(\\mathrm{stat}\\right)\\pm 0.05\\left(\\mathrm{syst}\\right)\\kern1em \\mathrm{f}\\mathrm{o}\\mathrm{r}\\kern1em 1.1<{q}^2<6.0\\kern0.5em {\\mathrm{GeV}}^2/{c}^4.\\hfill \\end{array}\\right. $

• Publisher: Springer
• Subject: High Energy Physics - Experiment / Physics