An exploratory lattice study of spectator effects in inclusive decays of the Λb baryon

1999/06/30 by Massimo Di Pierro, Chris T Sachrajda, Chris T. Sachrajda +1
Physics and Astronomy · #High-Energy Particle Collisions Research #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions #hep-lat

paper · pdf · doi:10.1016/s0370-2693(99)01166-1

published as Phys.Lett.B468:143,1999 · 12 pages, Latex. One correction: in the original version of the paper, in eqs.10, 11, 12 and 39, the values of the pion masses appeared interchanged

openalex publication_date 1999/11/01 · arxiv created 2001/12/07 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28

Abstract

A possible explanation of the apparent disrepency between the theoretical prediction and experimental measurement of the ratio of lifetimes τ(Λ_b)/τ(B_d) is that ``spectator effects'', which appear at O(1/m_b³) in the heavy quark expansion, contribute significantly. We investigate this possibility by computing the corresponding operator matrix elements in a lattice simulation. We find that spectator effects are indeed significant, but do not appear to be sufficiently large to account for the full discrepency. We stress, however, that this is an exploratory study, and it is important to check our conclusions on a larger lattice and using a larger sample of gluon configurations.

Citations

• Effect of tree-level and mean-field improvement on the light-hadron spectrum in quenched QCD
• Maximal variance reduction for stochastic propagators with applications to the static quark spectrum
• Enhancement of the Λ decay rate