{"paper":{"title":"How sensitive to FCNC can $B^0$ CP asymmetries be?","license":"","headline":"","cross_cats":[],"primary_cat":"hep-ph","authors_text":"(2) Theory Division, CERN, CFIF/IST, Dept. Fisica, F.J.Botella (1), G. Barenboim (1), G.C.Branco (2), IFIC, Instituto Superior Tecnico, Lisboa), O.Vives (1) ((1)Departament de Fisica Teorica, Universitat de Valencia","submitted_at":"1997-09-17T15:59:57Z","abstract_excerpt":"We show that the study of CP asymmetries in neutral B-meson decays provides a very sensitive probe of flavour-changing neutral currents (FCNC). We introduce two new angles, $\\alpha_{SM}$ and $\\beta_{SM}$, whose main feature is that they can be readily obtained from the measurement of the CP asymmetries $a_{J/\\psi K_s}$, $a_{\\pi^+ \\pi^-}$ and the ratio $R_u \\equiv|V_{ud}V_{ub}^*|/|V_{cd}V_{cb}^*|$, providing a quantitative test of the presence of new physics in a model-independent way.\n  Assuming that new physics is due to the presence of an isosinglet down-type quark, we indicate how to recons"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"hep-ph/9709369","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"}