2011/12/05 by M. Ablikim, BESIII Collaboration, M. N. Achasov +98 · 1 citation
Physics and Astronomy · #Computer science #High-Energy Particle Collisions Research #Particle physics theoretical and experimental studies #Physics #Quantum Chromodynamics and Particle Interactions #hep-ex
paper · pdf · doi:10.1103/physrevlett.108.112003
5 pages, 3 figures, submitted to Phys. Rev. Lett
arxiv created 2011/12/05 · openalex publication_date 2012/03/16 · arxiv updated 2013/05/29 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
A partial wave analysis of the pp mass-threshold enhancement in the reaction J/\ensuremathψ\ensuremath→\ensuremathγpp is used to determine its JPC quantum numbers to be 0^\ensuremath-+, its peak mass to be below threshold at M=1832_\ensuremath-5+19(stat)_\ensuremath-17+18(syst)\ifmmode±\else\textpm\fi19(model) MeV/c2, and its total width to be \ensuremathΓ<76 MeV/c2 at the 90% C.L. The product of branching ratios is measured to be BR[J/\ensuremathψ\ensuremath→\ensuremathγX(pp)]BR[X(pp)\ensuremath→pp]=[9.0_\ensuremath-1.1+0.4(stat)_\ensuremath-5.0+1.5(syst)\ifmmode±\else\textpm\fi2.3(model)]\ifmmode×\else\texttimes\fi10^\ensuremath-5. A similar analysis performed on \ensuremathψ(3686)\ensuremath→\ensuremathγpp decays shows, for the first time, the presence of a corresponding enhancement with a production rate relative to that for J/\ensuremathψ decays of R=[5.08_\ensuremath-0.45+0.71(stat)_\ensuremath-3.58+0.67(syst)\ifmmode±\else\textpm\fi0.12(model)]%.