Analysis of the D+→K-π+e+νe [D superscript + → K superscript - pi superscript + e superscript + v subscript e] decay channel

Abstract

Using 347.5 fb-1 [fb superscript -1] of data recorded by the BABAR detector at the PEP-II electron-positron collider, 244×103 [244 X 10 superscript 3] signal events for the D+→K-π+e+νe [D superscript + → K superscript - pi superscript + e superscript + v subscript e] decay channel are analyzed. This decay mode is dominated by the K̅ *(892)0 [K overscore superscript * (892) superscript 0] contribution. We determine the K̅ *(892)0 [K overscore superscript * (892) superscript 0] parameters: mK*(892)0=(895.4±0.2±0.2) [m subscript K * (892) 0 = 895.4±0.2±0.2)] MeV/c2 [MeV / c superscript 2], ΓK*(892)00=(46.5±0.3±0.2) [Gamma superscript 0 subscript K * (892) 0 = (46.5±0.3±0.2)] MeV/c2 [MeV / c superscript 2], and the Blatt-Weisskopf parameter rBW=2.1±0.5±0.5 [r subscript BW = 2.1±0.5±0.5](GeV/c)-1 [(GeV / c) superscript -1], where the first uncertainty comes from statistics and the second from systematic uncertainties. We also measure the parameters defining the corresponding hadronic form factors at q2=0 [q superscript 2 =0](rV=V(0)/A1(0)=1.463±0.017±0.031 [r subscript V = V(0) over A subscript 1 (0) = 1.463±0.017±0.031], r2=A2(0)/A1(0)=0.801±0.020±0.020 [r subscript 2 = A subscript 2 (0) over A subscript 1 (0) = 0.801±0.020±0.020]) and the value of the axial-vector pole mass parametrizing the q2 [q superscript 2] variation of A1 [A subscript 1] and A2 [A subscript 2]: mA=(2.63±0.10±0.13) [m subscript A = (2.63±0.10±0.13)] GeV/c2 [GeV / c superscript 2]. The S-wave fraction is equal to (5.79±0.16±0.15)%. Other signal components correspond to fractions below 1%. Using the D+→K-π+π+ [D superscript + → K superscript - pi superscript + pi superscript -] channel as a normalization, we measure the D+ [D superscript +] semileptonic branching fraction: B(D+→K-π+e+νe)=(4.00±0.03±0.04±0.09)×10-2 [Beta (D superscript + → K superscript - pi superscript + e superscript + v subscript e) = (4.00±0.03±0.04±0.09) X 10 superscript -2], where the third uncertainty comes from external inputs. We then obtain the value of the hadronic form factor A1 [A subscript 1] at q2=0 [q superscript 2 = 0]: A1(0)=0.6200±0.0056±0.0065±0.0071 [A subscript 1 (0) = 0.6200±0.0056±0.0065±0.0071]. Fixing the P-wave parameters, we measure the phase of the S wave for several values of the Kπ [K pi] mass. These results confirm those obtained with Kπ [K pi] production at small momentum transfer in fixed target experiments.