We establish improved upper limits on branching fractions for B0 decays to final states where the decay products are purely invisible (i.e., no observable final state particles) and for final states where the only visible product is a photon. Within the Standard Model, these decays have branching fractions that are below the current experimental sensitivity, but various models of physics beyond the Standard Model predict significant contributions for these channels. Using 471×106 BB̅ pairs collected at the Υ(4S) resonance by the BABAR experiment at the PEP-II e+e- storage ring at the SLAC National Accelerator Laboratory, we establish upper limits at the 90% confidence level of 2.4×10-5 for the branching fraction of B0→invisible and 1.7×10-5 for the branching fraction of B0→invisible+γ.
Improved limits on B^{0} decays to invisible (+γ) final states
LO VETERE, MAURIZIO;MONGE, MARIA ROBERTA;
2012-01-01
Abstract
We establish improved upper limits on branching fractions for B0 decays to final states where the decay products are purely invisible (i.e., no observable final state particles) and for final states where the only visible product is a photon. Within the Standard Model, these decays have branching fractions that are below the current experimental sensitivity, but various models of physics beyond the Standard Model predict significant contributions for these channels. Using 471×106 BB̅ pairs collected at the Υ(4S) resonance by the BABAR experiment at the PEP-II e+e- storage ring at the SLAC National Accelerator Laboratory, we establish upper limits at the 90% confidence level of 2.4×10-5 for the branching fraction of B0→invisible and 1.7×10-5 for the branching fraction of B0→invisible+γ.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.