Determination of the X(3872) Meson Quantum Numbers

LHCb collaboration

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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) -> pi(+) pi(-) j/psi and J/psi -> pi(+) mu(-). 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.
Original languageEnglish
Article number222001
Number of pages8
JournalPhysical Review Letters
Issue number22
Publication statusPublished - 29 May 2013
Externally publishedYes



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