000001179 001__ 1179
000001179 005__ 20181025124446.0
000001179 037__ $$aBELLE2-TALK-CONF-2018-126
000001179 041__ $$aeng
000001179 088__ $$aBELLE2-TALK-DRAFT-2018-111
000001179 100__ $$aAlan Schwartz
000001179 245__ $$aSemileptonic and leptonic D decays at Belle II
000001179 260__ $$aCKM 2018$$c2018-09-18
000001179 300__ $$amult. p
000001179 500__ $$a20 min
000001179 520__ $$aWe 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. 
000001179 8560_ $$fdoris.yangsoo.kim@desy.de
000001179 8564_ $$uhttps://docs.belle2.org/record/1179/files/BELLE2-TALK-CONF-2018-126.pdf