A sample of 3.6 million hadronic Z decays recorded between 1991 and 1995 with the ALEPH detector at LEP is used to investigate semileptonic decays of B mesons into final states involving orbitally excited charm mesons. Topological vertex criteria are used to search for decays involving narrow D** states as well as wide D** resonances and non-resonant D(*)pi final states. The sum of the branching ratios for these processes is measured to be Br((B) over bar --> D pi l(-)(v) over bar) + Br((B) over bar --> D*pi l(-)(v) over bar)= (2.26 +/- 0.29(stat) +/- 0.33(syst))%, which accounts for a significant fraction of the deficit between inclusive measurements and the sum of exclusive semileptonic B decay modes.
Production of orbitally excited charm mesons in semileptonic B decays
RIZZO, GIULIANA;BATIGNANI, GIOVANNI;BETTARINI, STEFANO;CIOCCI, MARIA AGNESE;FERRANTE, ISIDORO;FORTI, FRANCESCO;GIORGI, MARCELLO;MESSINEO, ALBERTO MARIA;TONELLI, GUIDO EMILIO;
1997-01-01
Abstract
A sample of 3.6 million hadronic Z decays recorded between 1991 and 1995 with the ALEPH detector at LEP is used to investigate semileptonic decays of B mesons into final states involving orbitally excited charm mesons. Topological vertex criteria are used to search for decays involving narrow D** states as well as wide D** resonances and non-resonant D(*)pi final states. The sum of the branching ratios for these processes is measured to be Br((B) over bar --> D pi l(-)(v) over bar) + Br((B) over bar --> D*pi l(-)(v) over bar)= (2.26 +/- 0.29(stat) +/- 0.33(syst))%, which accounts for a significant fraction of the deficit between inclusive measurements and the sum of exclusive semileptonic B decay modes.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.