{"paper":{"title":"Impact of polarization observables and $ B_c\\to \\tau \\nu$ on new physics explanations of the $b\\to c \\tau \\nu$ anomaly","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"hep-ph","authors_text":"Andreas Crivellin, Ivan Ni\\v{s}and\\v{z}i\\'c, Marta Moscati, Monika Blanke, Stefan de Boer, Teppei Kitahara, Ulrich Nierste","submitted_at":"2018-11-23T18:57:36Z","abstract_excerpt":"The combined analysis of the BaBar, Belle, and LHCb data on $B\\to D\\tau\\nu$, $B\\to D^*\\tau\\nu$ and $B_c\\to J/\\Psi\\tau\\nu$ decay observables shows evidence of physics beyond the Standard Model (SM). In this article, we study all the one- and two-dimensional scenarios which can be generated by adding a single new particle to the SM. We put special emphasis on the model-discriminating power of $F_L(D^*)$ and of the $\\tau$ polarizations, and especially on the constraint from the branching fraction ${\\rm BR}(B_c\\to\\tau\\nu)$. We critically review this constraint and do not support the aggressive lim"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1811.09603","kind":"arxiv","version":3},"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"}