Charm-quark mass effects in NRQCD matching coefficients and the leptonic decay of the ${\rm Y}(1S)$ meson

Manuel Egner, Matteo Fael, Jan Piclum +2

We compute two-loop corrections to the vector current matching coefficient involving two heavy quark masses. The result is applied to the computation of the ${\rm Y}(1S)$ decay width int…