Prediction of isoscalar charmoniumlike structures in the hidden-charm di-eta decays of higher charmonia

Considering the situation that a single chiral particle, η is initially emitted, we study the hidden-charm di-eta decays of the charmoniumlike state and the predicted charmonium , i.e., through the inetermediates and/or , and answer the important question

考虑最初发射单个手征粒子η的情况，我们研究类粲偶素态和预测的粲偶素的隐粲双η衰变，即通过中间态和/或，并回答重要问题。