Alan Schwartz

18 September 2018
CKM 2018

Abstract: We present Belle II prospects for measuring leptonic and semileptonic decays of D mesons. The branching fraction of leptonic decays provides a measurement of the decay constant times the magnitude of CKM matrix elements Vcd or Vcs. The differential decay rate of semileptonic decays provides a measurement of the form factor f+ times the magnitude of Vcd or Vcs. Inputting values of the decay constant or form factor as calculated from lattice QCD allows one to determine |Vcd| or |Vcs| and thus test the unitarity of the CKM matrix. Belle II should collect about 50 times as much data as Belle collected and determine |Vcd| and |Vcs| with about 7 times better precision.

Note: 20 min