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Home > Research > Publications & Outputs > Improved search for B(0)S anti-B(0)S oscillations
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Improved search for B(0)S anti-B(0)S oscillations

Research output: Contribution to journalJournal article

Published

Journal publication date07/2003
JournalThe European Physical Journal C (EPJ C) - Particles and Fields
Journal number2
Volume29
Number of pages28
Pages143-170
Original languageEnglish

Abstract

An improved search for B s 0 oscillations is performed in the ALEPH data sample collected during the first phase of LEP, and reprocessed in 1998. Three analyses based on complementary event selections are presented. First, decays of B s 0 mesons into hadronic flavour eigenstates are fully reconstructed. This selection yields a small sample of candidates with excellent decay length and momentum resolution and hi gh average B s 0 purity. Semileptonic decays with a reconstructed D s - meson provide a second sample with larger statistics, high average B s 0 purity, but a poorer momentum and decay length resolution due to the partial decay reconstruction. Finally, semileptonic b-hadron decays are inclusively selected and yield the data sample with the highest sensitivity to B s 0 oscillations, as the much higher statistics compensate for the low average B s 0 purity and poorer time resolution. A lower limit is set at Δms>10.9 ps-1 at 95% C.L., significantly lower than the expected limit of 15.2 ps-1.