2011/04/30 by S. Dubnička, Stanislav Dubnicka, Anna Z. Dubnickova +8 · 1 citation
Physics and Astronomy · #High-Energy Particle Collisions Research #Meson #Multipole expansion #Particle physics #Particle physics theoretical and experimental studies #Physics #Quantum Chromodynamics and Particle Interactions #Quantum chromodynamics #Quantum mechanics #Quark #Quark model #Quarkonium #hep-ph
paper · pdf · doi:10.1103/physrevd.84.014006
published as Phys.Rev.D84:014006,2011 · 13 pages, 5 figures. Typos corrected, version matching the one published in PRD
openalex publication_date 2011/07/06 · arxiv created 2011/08/08 · arxiv updated 2011/08/17 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We further explore the consequences of treating the X(3872) meson as a tetraquark bound state by analyzing its one-photon decay X\ensuremath→\ensuremathγ+J/\ensuremathψ in the framework of our approach developed in previous papers which incorporates quark confinement in an effective way. To introduce electromagnetism we gauge a nonlocal effective Lagrangian describing the interaction of the X(3872) meson with its four constituent quarks by using the P-exponential path-independent formalism. We calculate the matrix element of the transition X\ensuremath→\ensuremathγ+J/\ensuremathψ and prove its gauge invariance. We evaluate the X\ensuremath→\ensuremathγ+J/\ensuremathψ decay width and the longitudinal/transverse composition of the J/\ensuremathψ in this decay. For a reasonable value of the size parameter of the X(3872) meson we find consistency with the available experimental data. We also calculate the helicity and multipole amplitudes of the process, and describe how they can be obtained from the covariant transition amplitude by covariant projection.