A data sample of about 3.0 million hadronic Z decays collected by the ALEPH experiment at LEP in the years 1991 through 1994 is used to make an inclusive selection of B hadron events. In this event sample 4227±140±252 B* mesons in the decay B*→Bγ and 1944±108±161 B** u,d mesons decaying into a B meson and a charged pion are reconstructed. Here and in the following B** u,d denotes the eight L=1(bū) and (bd) states and their charge conjugate. For the well established B* meson the following quantities are obtained:ΔM=M B*-MB=(45.30±0.35±0.87) MeV/c2 and N B*/(N B+N B*)=(77.1±2.6±7.0)%. The angular distribution of the photons in the B* rest frame is used to measure the relative contribution of longitudinal B* polarization states to be σ L/(σ L+σ T)=(33±6±5)%. In the M(Bπ)-M(B) mass difference resonance structure is observed at (424±4±10) MeV/c2, for which the shape and position is consistent with the expectation for B** u,d states decaying into B(*)π ±. The relative production rate is determined to be {Mathematical expression} where the third error reflects the uncertainty due to different production and decay models for the broad B** u,d states. © 1996 Springer-Verlag.
Production of excited beauty states inZ decays
Colaleo, A.;Girone, M.;Iaselli, G.;Natali, S.;Nuzzo, S.;Selvaggi, G.;Zito, G.;Huang, X.;Zhang, J.;Cattaneo, M.;Antonelli, A.;Smith, K.;Brown, D.;Jacquet, M.;Bozzi, C.;Ferrante, I.;Spagnolo, P.;Triggiani, G.;
1995-01-01
Abstract
A data sample of about 3.0 million hadronic Z decays collected by the ALEPH experiment at LEP in the years 1991 through 1994 is used to make an inclusive selection of B hadron events. In this event sample 4227±140±252 B* mesons in the decay B*→Bγ and 1944±108±161 B** u,d mesons decaying into a B meson and a charged pion are reconstructed. Here and in the following B** u,d denotes the eight L=1(bū) and (bd) states and their charge conjugate. For the well established B* meson the following quantities are obtained:ΔM=M B*-MB=(45.30±0.35±0.87) MeV/c2 and N B*/(N B+N B*)=(77.1±2.6±7.0)%. The angular distribution of the photons in the B* rest frame is used to measure the relative contribution of longitudinal B* polarization states to be σ L/(σ L+σ T)=(33±6±5)%. In the M(Bπ)-M(B) mass difference resonance structure is observed at (424±4±10) MeV/c2, for which the shape and position is consistent with the expectation for B** u,d states decaying into B(*)π ±. The relative production rate is determined to be {Mathematical expression} where the third error reflects the uncertainty due to different production and decay models for the broad B** u,d states. © 1996 Springer-Verlag.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.


