Radiative transitions between 0−+ and 1−− heavy quarkonia on the light front

Meijian Li, Yang Li, Pieter Maris, James P. Vary
2018 Physical Review D  
We present calculations of radiative transitions between vector and pseudoscalar quarkonia in the light-front Hamiltonian approach. The valence sector light-front wavefunctions of heavy quarkonia are obtained from the Basis Light-Front Quantization (BLFQ) approach in a holographic basis. We study the transition form factor with both the traditional "good current" J^+ and the transverse current J⃗_ (in particular, J^R=J^x+i J^y). This allows us to investigate the role of rotational symmetry by
more » ... nsidering vector mesons with different magnetic projections (m_j=0,± 1). We use the m_j=0 state of the vector meson to obtain the transition form factor, since this procedure employs the dominant spin components of the light-front wavefunctions and is more robust in practical calculations. While the m_j=± 1 states are also examined, transition form factors depend on subdominant components of the light-front wavefunctions and are less robust. Transitions between states below the open-flavor thresholds are computed, including those for excited states. Comparisons are made with the experimental measurements as well as with Lattice QCD and quark model results. In addition, we apply the transverse current to calculate the decay constant of vector mesons where we obtain consistent results using either m_j=0 or m_j=1 light-front wavefunctions. This consistency provides evidence for features of rotational symmetry within the model.
doi:10.1103/physrevd.98.034024 fatcat:r3uzzzhglvhgdlkobuidy6dl5a