Hadronic mass spectrum analysis of D+→K−π+μ+ν decay and measurement of the K∗(892)0 mass and width

Abstract We present a Kπ mass spectrum analysis of the four-body semileptonic charm decay D + → K − π + μ + ν in the range of 0.65 GeV / c 2 m K π 1.5 GeV / c 2 . We observe a non-resonant contribution of 5.30 ± 0.74 −0.96 +0.99 % with respect to the total D + → K − π + μ + ν decay. For the K ∗ ( 892 ) 0 resonance, we obtain a mass of 895.41 ± 0.32 −0.43 +0.35 MeV / c 2 , a width of 47.79 ± 0.86 −1.06 +1.32 MeV / c 2 , and a Blatt–Weisskopf damping factor parameter of 3.96 ± 0.54 −0.90 +1.31 GeV −1 . We also report 90% CL upper limits of 4% and 0.64% for the branching ratios Γ ( D + → K ¯ ∗ ( 1680 ) 0 μ + ν ) Γ ( D + → K − π + μ + ν ) and Γ ( D + → K ¯ 0 ∗ ( 1430 ) 0 μ + ν ) Γ ( D + → K − π + μ + ν ) , respectively.