Pionic transitions from $$Z_c(4020)$$ to D wave charmonia

Abstract

AbstractIn the present work, we investigate the charmed meson loops contributions to the pionic transitions from $$Z_c(4020)^+$$ Z c ( 4020 ) + to the D wave triplets charmonia by using an effective Lagrangian approach. Our estimations indicate that the predicted branching fraction of $$Z_c(4020)^+ \rightarrow \pi ^+ \psi (1^3D_J), \ J=(1,2,3)$$ Z c ( 4020 ) + → π + ψ ( 1 3 D J ) , J = ( 1 , 2 , 3 ) are much smaller than the one of $$Z_c(4020)^+ \rightarrow \pi ^+ h_c $$ Z c ( 4020 ) + → π + h c . Thus, searching $$Z_c(4020)^\pm $$ Z c ( 4020 ) ± in the $$\pi ^\pm \psi (1^3D_J) $$ π ± ψ ( 1 3 D J ) invariant mass distributions is impossible. Thus, the observed peak structures at 4.04 and 4.13 GeV in the $$\pi ^\pm \psi (3770)$$ π ± ψ ( 3770 ) invariant mass distributions should not come from the contributions of $$Z_c(4020)^\pm $$ Z c ( 4020 ) ± , and further precise experimental measurements of the $$e^+ e^- \rightarrow \pi ^+ \pi ^- \psi (3770)$$ e + e - → π + π - ψ ( 3770 ) process are needed to decode the nature of these two peak structures.