Investigating the two-pion exchange of the double charm $D{D}^{\ast }$ chiral interactions and $T_{cc}$

Hao Xu, Li-xiang Ren

Under chiral effective field theory, we study the $S$-wave $D{D}^{\ast }$ interactions up to second chiral order at one-loop level, which contain full contact, one-pion-exchange (OPE) and…