Using 347.5 fb-1 of data recorded by the BABAR detector at the PEP-II electron-positron collider, 244×103 signal events for the D+→K-π+e+νe decay channel are analyzed. This decay mode is dominated by the K̅ *(892)0 contribution. We determine the K̅ *(892)0 parameters: mK*(892)0=(895.4±0.2±0.2) MeV/c2, ΓK*(892)00=(46.5±0.3±0.2) MeV/c2, and the Blatt-Weisskopf parameter rBW=2.1±0.5±0.5 (GeV/c)-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 (rV=V(0)/A1(0)=1.463±0.017±0.031, r2=A2(0)/A1(0)=0.801±0.020±0.020) and the value of the axial-vector pole mass parametrizing the q2 variation of A1 and A2: mA=(2.63±0.10±0.13) GeV/c2. 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+ channel as a normalization, we measure the D+ semileptonic branching fraction: B(D+→K-π+e+νe)=(4.00±0.03±0.04±0.09)×10-2, where the third uncertainty comes from external inputs. We then obtain the value of the hadronic form factor A1 at q2=0: A1(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 mass. These results confirm those obtained with Kπ production at small momentum transfer in fixed target experiments.
Analysis of the D^{+}→K^{-}π^{+}e^{+}ν_{e} decay channel
LO VETERE, MAURIZIO;MONGE, MARIA ROBERTA;PATRIGNANI, CLAUDIA;TOSI, SILVANO;
2011-01-01
Abstract
Using 347.5 fb-1 of data recorded by the BABAR detector at the PEP-II electron-positron collider, 244×103 signal events for the D+→K-π+e+νe decay channel are analyzed. This decay mode is dominated by the K̅ *(892)0 contribution. We determine the K̅ *(892)0 parameters: mK*(892)0=(895.4±0.2±0.2) MeV/c2, ΓK*(892)00=(46.5±0.3±0.2) MeV/c2, and the Blatt-Weisskopf parameter rBW=2.1±0.5±0.5 (GeV/c)-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 (rV=V(0)/A1(0)=1.463±0.017±0.031, r2=A2(0)/A1(0)=0.801±0.020±0.020) and the value of the axial-vector pole mass parametrizing the q2 variation of A1 and A2: mA=(2.63±0.10±0.13) GeV/c2. 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+ channel as a normalization, we measure the D+ semileptonic branching fraction: B(D+→K-π+e+νe)=(4.00±0.03±0.04±0.09)×10-2, where the third uncertainty comes from external inputs. We then obtain the value of the hadronic form factor A1 at q2=0: A1(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 mass. These results confirm those obtained with Kπ production at small momentum transfer in fixed target experiments.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.