The quantum numbers of the X(3872) meson are determined to be JPC=1 ++ based on angular correlations in B+→X(3872)K + decays, where X(3872)→π+π-J/ψ ; 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 JPC=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. © 2013 CERN. Published by the American Physical Society under the terms of the Creative Commons Attribution 3.0 License. Further distribution of this work must maintain attribution to the author(s) ; the published article's title, journal citation, ; DOI.
Determination of the X(3872) Meson Quantum Numbers
PALANO, Antimo;PAPPAGALLO, MARCO IGNAZIO;
2013-01-01
Abstract
The quantum numbers of the X(3872) meson are determined to be JPC=1 ++ based on angular correlations in B+→X(3872)K + decays, where X(3872)→π+π-J/ψ ; 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 JPC=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. © 2013 CERN. Published by the American Physical Society under the terms of the Creative Commons Attribution 3.0 License. Further distribution of this work must maintain attribution to the author(s) ; the published article's title, journal citation, ; DOI.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.