B0B0 oscillation is studied using almost a million hadronic Z decays collected by the ALEPH experiment at LEP. Events are selected with two leptons present, on opposite sides of the event and with high transverse momentum. The leptons are expected to be dominantly from b decays; a topological vertexing technique is applied to measure the decay length of the b hadrons, and their momentum is determined using an energy-flow method. The fraction of events in which the leptons have the same charge is studied as a function of the measured decay time, and clear evidence is seen for the time-dependent nature of Bd 0Bd 0 mixing. The frequency measured for the oscillation corresponds to a mass difference for the Bd 0 mass eigenstates Δmd = (3.3-0.4 +0.5 ± 0.7) × 10-4 eV/c2. Allowing a second frequency component for the Bs 0 a high value for Δms is favoured, leading to the limit Δms > 12 × 10-4 eV/c2 (95% CL), from which (Δm/Γ)s > 2.0 is derived.

Buskulic, D., Debonis, I., Decamp, D., Ghez, P., Goy, C., Lees, J., et al. (1994). An investigation of Bd 0 and Bs 0 oscillation. PHYSICS LETTERS. SECTION B, 322(4), 441-458 [10.1016/0370-2693(94)91177-0].

An investigation of Bd 0 and Bs 0 oscillation

CARPINELLI, Massimo;
1994

Abstract

B0B0 oscillation is studied using almost a million hadronic Z decays collected by the ALEPH experiment at LEP. Events are selected with two leptons present, on opposite sides of the event and with high transverse momentum. The leptons are expected to be dominantly from b decays; a topological vertexing technique is applied to measure the decay length of the b hadrons, and their momentum is determined using an energy-flow method. The fraction of events in which the leptons have the same charge is studied as a function of the measured decay time, and clear evidence is seen for the time-dependent nature of Bd 0Bd 0 mixing. The frequency measured for the oscillation corresponds to a mass difference for the Bd 0 mass eigenstates Δmd = (3.3-0.4 +0.5 ± 0.7) × 10-4 eV/c2. Allowing a second frequency component for the Bs 0 a high value for Δms is favoured, leading to the limit Δms > 12 × 10-4 eV/c2 (95% CL), from which (Δm/Γ)s > 2.0 is derived.
Articolo in rivista - Articolo scientifico
Z0 DECAYS; STRENGTH; COLLIDER; LEP;
English
1994
322
4
441
458
none
Buskulic, D., Debonis, I., Decamp, D., Ghez, P., Goy, C., Lees, J., et al. (1994). An investigation of Bd 0 and Bs 0 oscillation. PHYSICS LETTERS. SECTION B, 322(4), 441-458 [10.1016/0370-2693(94)91177-0].
File in questo prodotto:
Non ci sono file associati a questo prodotto.

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10281/390399
Citazioni
  • Scopus 47
  • ???jsp.display-item.citation.isi??? 46
Social impact