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Hajime Muramatsu
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Leptonic Decays of Charmed Mesons at BESIII
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BESIII now holds the world's largest e+e-
annihilation samples taken at Ecm = 3.773,
4.009, and 4.178 GeV which produce copious
charmed mesons, D0, D+, and Ds+.
In this talk, I would like to report our
studies on Ds -> mu nu and 
D+ -> l nu (l = mu and tau), along with other
prospective analyses in Ds decays.
These allow us to determine the elements
of the CKM matrix 
within the standard model, probe lepton universality,
as well as to calibrate the LQCD calculations
of fD(s)+ and to test the unitarity
of the first and second rows of the CKM matrix.

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