Measuring violation in using excited charm mesons
Daniel Aloni (Department of Particle Physics and Astrophysics, Weizmann Institute of Science, Rehovot 7610001, Israel); Yuval Grossman (Department of Physics, LEPP, Cornell University, Ithaca, New York 14853, USA); Abner Soffer (Raymond and Beverly Sackler School of Physics and Astronomy, Tel Aviv University, Tel Aviv 6997801, Israel)
There is growing evidence for deviation from the standard model predictions in the ratios between semitauonic and semileptonic decays, known as the puzzle. If the source of this nonuniversality is new physics, it is natural to assume that it also breaks symmetry. In this paper we study the possibility of measuring violation in semitauonic decays, exploiting interference between excited charm mesons. Given the current values of , we find that our proposed -violation observable could be as large as about 10%. We discuss the experimental advantages of our method and propose carrying it out at Belle II and LHCb.
