Determination of the X(3872) meson quantum numbers

• Published in: Physical review letters 2013-05, Vol.110 (22), p.222001-222001, Article 222001
• Main Authors: Aaij, R, Abellan Beteta, C, Adeva, B, Adinolfi, M, Adrover, C, Affolder, A, Ajaltouni, Z, Albrecht, J, Alessio, F, Alexander, M, Ali, S, Alkhazov, G, Alvarez Cartelle, P, Alves, Jr, A A, Amato, S, Amerio, S, Amhis, Y, Anderlini, L, Anderson, J, Andreassen, R, Appleby, R B, Aquines Gutierrez, O, Archilli, F, Artamonov, A, Artuso, M, Aslanides, E, Auriemma, G, Bachmann, S, Back, J J, Baesso, C, Balagura, V, Baldini, W, Barlow, R J, Barschel, C, Barsuk, S, Barter, W, Bauer, Th, Bay, A, Beddow, J, Bedeschi, F, Bediaga, I, Belogurov, S, Belous, K, Belyaev, I, Ben-Haim, E, Benayoun, M, Bencivenni, G, Benson, S, Benton, J, Berezhnoy, A, Bernet, R, Bettler, M -O, van Beuzekom, M, Bien, A, Bifani, S, Bird, T, Bizzeti, A, Bjørnstad, P M, Blake, T, Blanc, F, Blouw, J, Blusk, S, Bocci, V, Bondar, A, Bondar, N, Bonivento, W, Borghi, S, Borgia, A, Bowcock, T J V, Bowen, E, Bozzi, C, Brambach, T, van den Brand, J, Bressieux, J, Brett, D, Britsch, M, Britton, T, Brook, N H, Brown, H, Burducea, I, Bursche, A, Busetto, G, Buytaert, J, Cadeddu, S, Callot, O, Calvi, M, Calvo Gomez, M, Camboni, A, Campana, P, Carbone, A, Carboni, G, Cardinale, R, Cardini, A, Carranza-Mejia, H, Carson, L, Carvalho Akiba, K, Casse, G, Cattaneo, M, Cauet, Ch, Charles, M
• Format: Article
• Language: English
• Subjects: Experiments; Física de partícules; High Energy Physics - Experiment; Particle physics; Physics
• ISSN: 0031-9007; 1079-7114
• DOI: 10.1103/PhysRevLett.110.222001

The quantum numbers of the X(3872) meson are determined to be J(PC)=1(++) based on angular correlations in B(+)→X(3872)K(+) decays, where X(3872)→π(+)π(-)J/ψ and J/ψ→μ(+)μ(-). The data correspond to 1.0 fb(-1) of pp collisions collected by the LHCb detector. The only alternative assignment allowed by previous measurements J(PC)=2(-+) is rejected with a confidence level equivalent to more than 8 Gaussian standard deviations using a likelihood-ratio test in the full angular phase space. This result favors exotic explanations of the X(3872) state.