Measurement of $D^0-\bar{D}^0$ mixing parameters using semileptonic decays of neutral kaon (1912.04955v2)

Abstract: We propose a new method to extract $D^0-\bar{D}^0$ mixing parameters using the $D^0 \to \bar{K}{}^0 \pi^0$ decay with the $\bar{K}{}^0$ reconstructed in the semileptonic mode. Although a $K^0 \to \pi^\pm l^\mp \nu_l$ decay suffers from low statistics and complexity of the secondary vertex reconstruction in comparison to the standard $K_{S} \to \pi^+ \pi^-$ vertex, it provides much richer, sometimes unique information about the initial state of a $K^0$-meson produced in a heavy-flavor hadron decay. In this paper it is shown that the reconstruction of the chain $D^0 \to K^0 (\pi^\pm l^\mp \nu_l) \pi^0$ allows one to extract the strong phase difference between the doubly Cabibbo-suppressed and Cabibbo-favored decay amplitudes, which is of key importance for determination of the $D^0-\bar{D}^0$ mixing parameters.