Journal article

Determination of the X(3872) meson quantum numbers

R Aaij, C Abellan Beteta, B Adeva, M Adinolfi, C Adrover, A Affolder, Z Ajaltouni, J Albrecht, F Alessio, M Alexander, S Ali, G Alkhazov, P Alvarez Cartelle, AA Alves, S Amato, S Amerio, Y Amhis, L Anderlini, J Anderson, R Andreassen Show all

Physical Review Letters | AMER PHYSICAL SOC | Published : 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. © 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..

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University of Melbourne Researchers

Grants

Awarded by National Science Foundation


Funding Acknowledgements

We express our gratitude to our colleagues in the CERN accelerator departments for the excellent performance of the LHC. We thank the technical and administrative staff at the LHCb institutes. We acknowledge support from CERN and from the following national agencies: CAPES, CNPq, FAPERJ, and FINEP (Brazil); NSFC (China); CNRS/IN2P3 and Region Auvergne (France); BMBF, DFG, HGF, and MPG (Germany); SFI (Ireland); INFN (Italy); FOM and NWO (Netherlands); SCSR (Poland); ANCS/IFA (Romania); MinES, Rosatom, RFBR, and NRC "Kurchatov Institute'' (Russia); MinECo, XuntaGal, and GENCAT (Spain); SNSF and SER (Switzerland); NAS Ukraine (Ukraine); STFC (United Kingdom); NSF (USA). We also acknowledge the support received from the ERC under FP7. The Tier1 computing centers are supported by IN2P3 (France), KIT and BMBF (Germany), INFN (Italy), NWO and SURF (Netherlands), PIC (Spain), and GridPP (United Kingdom). We are thankful for the computing resources put at our disposal by Yandex LLC (Russia), as well as to the communities behind the multiple open source software packages that we depend on.