{"paper":{"title":"Higher-Order Perturbative Corrections to $b\\to c$ Transitions at Zero Recoil","license":"","headline":"","cross_cats":[],"primary_cat":"hep-ph","authors_text":"Matthias Neubert","submitted_at":"1994-09-30T11:39:58Z","abstract_excerpt":"We estimate the two-loop perturbative corrections to zero-recoil matrix elements of the flavour-changing currents $\\bar c\\,\\gamma^\\mu b$ and $\\bar c\\,\\gamma^\\mu\\gamma_5\\,b$ by calculating the terms of order $n_f\\,\\alpha_s^2$ and substituting the dependence on the number of flavours by the first coefficient of the $\\beta$-function. Both for vector and axial vector currents, we find moderate two-loop corrections below 1\\% in magnitude. Using the Brodsky--Lepage--Mackenzie prescription to set the scale in the order-$\\alpha_s$ corrections in the $\\overline{\\rm MS}$ scheme, we obtain $\\mu_V\\simeq 0"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"hep-ph/9409453","kind":"arxiv","version":1},"verdict":{"id":null,"model_set":{},"created_at":null,"strongest_claim":"","one_line_summary":"","pipeline_version":null,"weakest_assumption":"","pith_extraction_headline":""},"references":{"count":0,"sample":[],"resolved_work":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","internal_anchors":0},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"}