2004/04/30 by Benjamin Grinstein, Dan Pirjol · 1 citation
Physics and Astronomy · #hep-ph
paper · pdf · doi:10.1103/physrevd.70.114005
published as Phys.Rev. D70 (2004) 114005 · 21 pages RevTex, 2 figures; v3: extensive numerical changes in the NLL analysis, with improved stability under scale dependence. Typos fixed, version to appear in Phys.Rev.D
arxiv created 2004/10/29 · arxiv updated 2009/12/01
We present a model-independent description of the exclusive rare decays B-> K* e+e- in the low recoil region (large lepton invariant mass q2 ~ mb2). In this region the long-distance effects from quark loops can be computed with the help of an operator product expansion in 1/Q, with Q=mb, √(q2). Nonperturbative effects up to and including terms suppressed by Lambda/Q and mc2/mb2 relative to the short-distance amplitude can be included in a model-independent way. Based on these results, we propose an improved method for determining the CKM matrix element |Vub| from a combination of rare and semileptonic B and D decays near the zero recoil point. The residual theoretical uncertainty from long distance effects in this |Vub| determination comes from terms in the OPE of order alphas(Q)Λ/mb, alphas2(Q), mc4/mb4 and duality violations and is estimated to be below 10%.