Observation of $D\to {\bar{K}}_1(1270)\hat{I}{¼}^{+}\hat{I}{½}_{\hat{I}}¼$ and test of lepton flavor universality with $D\to {\bar{K}}_1(1270){\ell }^{+}\hat{I}{½}_{\ell }$

BESIII Collaboration, M. Ablikim, M. N. Achasov +651

By analyzing 7.93 $\mathrm{f}{\mathrm{b}}^{-1}$ of $e^{+}{e}^{-}$ collision data collected at the center-of-mass energy of 3.773 GeV with the BESIII detector operated at the BEPCII collider, we report t…