Observation of D 0 Meson Decays to π + π − μ + μ − and K + K − μ + μ − Final States

• Published in: Physical review letters 2017-10, Vol.119 (18), Article 181805
• Main Authors: Aaij, R., Adeva, B., Adinolfi, M., Ajaltouni, Z., Akar, S., Albrecht, J., Alessio, F., Alexander, M., Alfonso Albero, A., Ali, S., Alkhazov, G., Alvarez Cartelle, P., Alves, A. A., Amato, S., Amerio, S., Amhis, Y., An, L., Anderlini, L., Andreassi, G., Andreotti, M., Andrews, J. E., Appleby, R. B., Archilli, F., d’Argent, P., Arnau Romeu, J., Artamonov, A., Artuso, M., Aslanides, E., Auriemma, G., Baalouch, M., Babuschkin, I., Bachmann, S., Back, J. J., Badalov, A., Baesso, C., Baker, S., Balagura, V., Baldini, W., Baranov, A., Barlow, R. J., Barschel, C., Barsuk, S., Barter, W., Baryshnikov, F., Batozskaya, V., Battista, V., Bay, A., Beaucourt, L., Beddow, J., Bedeschi, F., Bediaga, I., Beiter, A., Bel, L. J., Beliy, N., Bellee, V., Belloli, N., Belous, K., Belyaev, I., Ben-Haim, E., Bencivenni, G., Benson, S., Beranek, S., Berezhnoy, A., Bernet, R., Berninghoff, D., Bertholet, E., Bertolin, A., Betancourt, C., Betti, F., Bettler, M.-O., van Beuzekom, M., Bezshyiko, Ia, Bifani, S., Billoir, P., Birnkraut, A., Bitadze, A., Bizzeti, A., Bjørn, M., Blake, T., Blanc, F., Blouw, J., Blusk, S., Bocci, V., Boettcher, T., Bondar, A., Bondar, N., Bonivento, W., Bordyuzhin, I., Borgheresi, A., Borghi, S., Borisyak, M., Borsato, M., Bossu, F., Boubdir, M., Bowcock, T. J. V., Bowen, E., Bozzi, C., Braun, S., Britton, T., Brodzicka, J.
• Format: Article
• Language: English
• Subjects: High Energy Physics - Experiment; Physics
• ISSN: 0031-9007; 1079-7114
• DOI: 10.1103/PhysRevLett.119.181805

The first observation of the D0→π+π-μ+μ- and D0→K+K-μ+μ- decays is reported using a sample of proton-proton collisions collected by LHCb at a center-of-mass energy of 8 TeV, and corresponding to 2  fb-1 of integrated luminosity. The corresponding branching fractions are measured using as normalization the decay D0→K-π+[μ+μ-]ρ0/ω, where the two muons are consistent with coming from the decay of a ρ0 or ω meson. The results are B(D0→π+π-μ+μ-)=(9.64±0.48±0.51±0.97)×10-7 and B(D0→K+K-μ+μ-)=(1.54±0.27±0.09±0.16)×10-7, where the uncertainties are statistical, systematic, and due to the limited knowledge of the normalization branching fraction. The dependence of the branching fraction on the dimuon mass is also investigated.