Using a sample of four million hadronic Z events collected in ALEPH from 1991 to 1995, the decays D8+ --> D(0)pi(s)(+), with D-0 decaying to K- pi(+) or to K+ pi(-), are studied. The relative branching ratio B(D-0 --> K+ pi(-))/B(D-0 --> K- pi(+)) is measured to be (1.84 +/- 0.59(stat.) +/- 0.34(syst.))%. The two possible contributions to the D-0 --> K+ pi(-) decay, doubly Cabibbo-suppressed decays and DO-DO mixing, are disentangled by measuring the proper-time distribution of the reconstructed DO's. Assuming no interference between the two processes, the upper limit obtained on the mixing rate is 0.92% at 95% CL. The possible effect of interference between the two amplitudes is also assessed. (C) 1998 Elsevier Science B.V. All rights reserved.
Study of D-0-(D)over-bar(0) mixing and D-0 doubly Cabibbo-suppressed decays
ROLANDI, LUIGI;LIGABUE, FRANCO;LUSIANI, Alberto;
1998
Abstract
Using a sample of four million hadronic Z events collected in ALEPH from 1991 to 1995, the decays D8+ --> D(0)pi(s)(+), with D-0 decaying to K- pi(+) or to K+ pi(-), are studied. The relative branching ratio B(D-0 --> K+ pi(-))/B(D-0 --> K- pi(+)) is measured to be (1.84 +/- 0.59(stat.) +/- 0.34(syst.))%. The two possible contributions to the D-0 --> K+ pi(-) decay, doubly Cabibbo-suppressed decays and DO-DO mixing, are disentangled by measuring the proper-time distribution of the reconstructed DO's. Assuming no interference between the two processes, the upper limit obtained on the mixing rate is 0.92% at 95% CL. The possible effect of interference between the two amplitudes is also assessed. (C) 1998 Elsevier Science B.V. All rights reserved.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
