Search for excited Bc + states

Author(s): 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, AA; Amato, S; Amerio, S; Amhis, Y; An, L; Anderlini, L; Andreassi, G; Andreotti, M; Andrews, JE; Appleby, RB; Archilli, F; d’Argent, P; Arnau Romeu, J; Artamonov, A; Artuso, M; Aslanides, E; Atzeni, M; Auriemma, G; Baalouch, M; Babuschkin, I; Bachmann, S; Back, JJ; Badalov, A; Baesso, C; Baker, S; Balagura, V; Baldini, W; Baranov, A; Barlow, RJ; 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, LJ; 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, MO; van Beuzekom, M; Bezshyiko, I; Bifani, S; Billoir, P; Birnkraut, A; Bizzeti, A; Bjorn, M; Blake, T; Blanc, F; Blusk, S; Bocci, V; Boettcher, T; Bondar, A; Bondar, N | Abstract: © 2018, The Author(s). A search is performed in the invariant mass spectrum of the Bc+π+π− system for the excited Bc+ states Bc(21S0)+ and Bc(23S1)+ using a data sample of pp collisions collected by the LHCb experiment at the centre-of-mass energy of s=8 TeV, corresponding to an integrated luminosity of 2 fb−1. No evidence is seen for either state. Upper limits on the ratios of the production cross-sections of the Bc(21S0)+ and Bc(23S1)+ states times the branching fractions of Bc(21S0)+ → Bc+π+π− and Bc(23S1)+ → Bc*+π+π− over the production cross-section of the Bc+ state are given as a function of their masses. They are found to be between 0.02 and 0.14 at 95% confidence level for Bc(21S0)+ and Bc(23S1)+ in the mass ranges [6830, 6890] MeV/c2 and [6795, 6890] MeV/c2, respectively.[Figure not available: see fulltext.].