B-d(0) meson oscillations are measured in hadronic Z(0) decays using the charge of a lepton or the mean charge of an event hemisphere to sign the presence of a b or a (b) over bar quark when it is produced, and using the charge of a lepton emitted at large p(t) or of a D*(+/-) to sign the presence of a B or a (B) over bar meson when it decays. With 3.2 million hadronic Z(0) decays registered by DELPHI between 1991 and 1994, the mass difference Delta m(d) between the two physical B-d(0) states is measured in four channels: Delta m(d) = 0.523 +/- 0.072 +/- 0.043 ps(-1) (D*(+/-) - Q(hem)) Delta m(d) = 0.493 +/- 0.042 +/- 0.027 ps(-1) (l - Q(hem)) Delta m(d) = 0.499 +/- 0.053 +/- 0.015 ps(-1) ((pi* - l) - Q(hem) Delta m(d) = 0.480 +/- 0.040 +/- 0.051 ps(-1) (l - l). Taking into account the statistical overlap between these measurements and the common systematic uncertainties, the combined result is: Delta m(d) = 0.497 +/- 0.035 ps(-1).
Measurement of B-d(0)-(B-d(0))over-bar oscillations
DE ANGELIS, Alessandro;DE LOTTO, Barbara;SCURI, Fabrizio;
1997-01-01
Abstract
B-d(0) meson oscillations are measured in hadronic Z(0) decays using the charge of a lepton or the mean charge of an event hemisphere to sign the presence of a b or a (b) over bar quark when it is produced, and using the charge of a lepton emitted at large p(t) or of a D*(+/-) to sign the presence of a B or a (B) over bar meson when it decays. With 3.2 million hadronic Z(0) decays registered by DELPHI between 1991 and 1994, the mass difference Delta m(d) between the two physical B-d(0) states is measured in four channels: Delta m(d) = 0.523 +/- 0.072 +/- 0.043 ps(-1) (D*(+/-) - Q(hem)) Delta m(d) = 0.493 +/- 0.042 +/- 0.027 ps(-1) (l - Q(hem)) Delta m(d) = 0.499 +/- 0.053 +/- 0.015 ps(-1) ((pi* - l) - Q(hem) Delta m(d) = 0.480 +/- 0.040 +/- 0.051 ps(-1) (l - l). Taking into account the statistical overlap between these measurements and the common systematic uncertainties, the combined result is: Delta m(d) = 0.497 +/- 0.035 ps(-1).I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
