Improved measurement of the absolute branching fraction of D+→K¯0μ+νμ

By analyzing 2.93 fb -1 of data collected at s=3.773 GeV with the BESIII detector, we measure the absolute branching fraction B(D+→K¯0μ+νμ)=(8.72±0.07stat.±0.18sys.)% , which is consistent with previous measurements within uncertainties but with significantly improved precision. Combining the Particle Data Group values of B(D0→K-μ+νμ) , B(D+→K¯0e+νe) , and the lifetimes of the D0 and D+ mesons with the value of B(D+→K¯0μ+νμ) measured in this work, we determine the following ratios of partial widths: Γ(D0→K-μ+νμ)/Γ(D+→K¯0μ+νμ)=0.963±0.044 and Γ(D+→K¯0μ+νμ)/Γ(D+→K¯0e+νe)=0.988±0.033 .