2003/04/11 by B. Aubert, Aubert, B.
Physics and Astronomy · #High-Energy Particle Collisions Research #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions #hep-ex
paper · pdf · doi:10.48550/arxiv.hep-ex/0304020
Presented at XXXVIII Rencontres de Moriond on Electroweak Interactions and Unified Theories
arxiv created 2003/04/29 · arxiv updated 2009/11/30
We present a search for the rare flavour-changing neutral-current decay B-→ K- νν based on a sample of (86.9 ± 1.0) × 106 Υ(4S) → BB events collected by the BABAR experiment at the SLAC B-factory. Signal candidate events are selected by fully reconstructing a B+ → D0 X+ decay, where X+ represents a combination of up to three charged pions or kaons and up to two π0 candidates. The charged tracks and calorimeter clusters not used in the B+ reconstruction are required to be compatible with a B-→ K- νν decay. We observe a total of three signal candidate events with an expected background of 2.7 ± 0.8, resulting in a preliminary limit of B(B-→ K- νν) < 1.05 × 10-4 at the 90% confidence level. This search is combined with the results of a previous and statistically independent preliminary BABAR search for B-→ K- νν to give a limit of B(B-→ K- νν) < 7.0 × 10-5 at the 90% confidence level.