{"paper":{"title":"A Phenomenological Study of Semileptonic $B^+$ and $B_s^0$ Decays into Axial-Vector Mesons $\\big(D_1(2420),\\, D_1^\\prime(2430),\\, D_{s1}(2460),\\, \\text{and } D_{s1}^\\prime(2536)\\big)$ within the Standard Model","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"Branching ratios in semileptonic B decays to axial-vector mesons vary with the mixing angle between light angular momentum states.","cross_cats":[],"primary_cat":"hep-ph","authors_text":"Ishtiaq Ahmed, Qazi Maaz Us Salam, Rana Khan, Zohaib Aarfi","submitted_at":"2026-05-12T12:51:38Z","abstract_excerpt":"We study semileptonic $B$ meson decays $B^+ \\to D_1^{(\\prime)}\\ell^+\\nu_\\ell$ and $B_s^0 \\to D_{s1}^{-(\\prime)}\\ell^+\\nu_\\ell$, where $\\ell=\\mu,\\tau$. The final state axial vector mesons are treated as mixtures of the heavy quark basis states with light degree of freedom angular momenta $j_\\ell=1/2$ and $j_\\ell=3/2$, parametrized by the mixing angle $\\theta_{D_1}$. Using form factors obtained in the covariant light front quark model, we analyze the dependence of various observables on $\\theta_{D_1}$ such as polarized and unpolarized branching ratios, the lepton forward-backward asymmetry, the "},"claims":{"count":4,"items":[{"kind":"strongest_claim","text":"Our results show that branching ratios and other observables are sensitive to the axial-vector mixing structure. These predictions provide useful Standard Model benchmarks for future measurements of semileptonic B(s) decays into orbitally excited mesons and may help to clarify the long standing 1/2 vs. 3/2 puzzle.","source":"verdict.strongest_claim","status":"machine_extracted","claim_id":"C1","attestation":"unclaimed"},{"kind":"weakest_assumption","text":"The form factors are taken from the covariant light-front quark model without new validation for the specific axial-vector final states; the mixing angle parametrization is assumed to capture the dominant effect of the j_l = 1/2 and 3/2 components.","source":"verdict.weakest_assumption","status":"machine_extracted","claim_id":"C2","attestation":"unclaimed"},{"kind":"one_line_summary","text":"Semileptonic B decays to mixed axial-vector mesons show branching ratios and polarization observables that vary strongly with the D1 mixing angle in the covariant light-front quark model.","source":"verdict.one_line_summary","status":"machine_extracted","claim_id":"C3","attestation":"unclaimed"},{"kind":"headline","text":"Branching ratios in semileptonic B decays to axial-vector mesons vary with the mixing angle between light angular momentum states.","source":"verdict.pith_extraction.headline","status":"machine_extracted","claim_id":"C4","attestation":"unclaimed"}],"snapshot_sha256":"0094b7ae1a72f11b7b7d8a2dc85cd7df61e6a7c7c4dcd6f40f8b5f8677759a8b"},"source":{"id":"2605.12065","kind":"arxiv","version":2},"verdict":{"id":"c8427294-8d1a-4864-982d-ec96249a64b6","model_set":{"reader":"grok-4.3"},"created_at":"2026-05-13T05:03:53.947274Z","strongest_claim":"Our results show that branching ratios and other observables are sensitive to the axial-vector mixing structure. These predictions provide useful Standard Model benchmarks for future measurements of semileptonic B(s) decays into orbitally excited mesons and may help to clarify the long standing 1/2 vs. 3/2 puzzle.","one_line_summary":"Semileptonic B decays to mixed axial-vector mesons show branching ratios and polarization observables that vary strongly with the D1 mixing angle in the covariant light-front quark model.","pipeline_version":"pith-pipeline@v0.9.0","weakest_assumption":"The form factors are taken from the covariant light-front quark model without new validation for the specific axial-vector final states; the mixing angle parametrization is assumed to capture the dominant effect of the j_l = 1/2 and 3/2 components.","pith_extraction_headline":"Branching ratios in semileptonic B decays to axial-vector mesons vary with the mixing angle between light angular momentum states."},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/2605.12065/integrity.json","findings":[],"available":true,"detectors_run":[{"name":"ai_meta_artifact","ran_at":"2026-05-26T15:43:34.566915Z","status":"completed","version":"1.0.0","findings_count":0},{"name":"doi_title_agreement","ran_at":"2026-05-20T17:01:26.344718Z","status":"completed","version":"1.0.0","findings_count":0},{"name":"doi_compliance","ran_at":"2026-05-20T11:24:49.442390Z","status":"completed","version":"1.0.0","findings_count":0},{"name":"claim_evidence","ran_at":"2026-05-19T23:01:58.405324Z","status":"completed","version":"1.0.0","findings_count":0}],"snapshot_sha256":"b4262b705dfad0806b888e6e8b05e6b7fa4da1837fdc147c6e020fcec1e3d3c2"},"references":{"count":0,"sample":[],"resolved_work":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","internal_anchors":0},"formal_canon":{"evidence_count":2,"snapshot_sha256":"1a517c21ea68cb97bbaef2bd53872c6fa38d92cf8468503fb9064523a6ab3a4c"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"}