Using a sample of four million hadronic Z events collected in ALEPH from 1991 to 1995, the decays D*+ --> D(0)pi(+), 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 D(0)-(D)over bar(0) mixing, are disentangled by measuring the proper-time distribution of the reconstructed D0'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.
Study of D(0)-(D)over-bar(0) mixing and D(0) doubly Cabibbo-suppressed decays
G. Batignani;CIOCCI, MARIA AGNESE;FERRANTE, ISIDORO;MESSINEO, ALBERTO MARIA;TONELLI, GUIDO EMILIO;
1998-01-01
Abstract
Using a sample of four million hadronic Z events collected in ALEPH from 1991 to 1995, the decays D*+ --> D(0)pi(+), 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 D(0)-(D)over bar(0) mixing, are disentangled by measuring the proper-time distribution of the reconstructed D0'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.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.