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 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 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.
R. Aaij, C. Abellan Beteta, B. Adeva, M. Adinolfi, C. Adrover, A. Affolder, et al. (2013). Determination of the X(3872) Meson Quantum Numbers. PHYSICAL REVIEW LETTERS, 110(22), 1-8 [10.1103/PhysRevLett.110.222001].
Determination of the X(3872) Meson Quantum Numbers
CARBONE, ANGELO;GALLI, DOMENICO;PATRIGNANI, CLAUDIA;PERAZZINI, STEFANO;VAGNONI, VINCENZO MARIA;ZANGOLI, MARIA;
2013
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 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 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.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.