{"work":{"id":"a062be69-a4ae-4b49-ae09-ed08df21ebd3","openalex_id":null,"doi":null,"arxiv_id":"1705.05802","raw_key":null,"title":"Test of lepton universality with $B^{0} \\rightarrow K^{*0}\\ell^{+}\\ell^{-}$ decays","authors":null,"authors_text":"R","year":2017,"venue":"hep-ex","abstract":"A test of lepton universality, performed by measuring the ratio of the branching fractions of the $B^{0} \\rightarrow K^{*0}\\mu^{+}\\mu^{-}$ and $B^{0} \\rightarrow K^{*0}e^{+}e^{-}$ decays, $R_{K^{*0}}$, is presented. The $K^{*0}$ meson is reconstructed in the final state $K^{+}\\pi^{-}$, which is required to have an invariant mass within 100$\\mathrm{\\,MeV}c^2$ of the known $K^{*}(892)^{0}$ mass. The analysis is performed using proton-proton collision data, corresponding to an integrated luminosity of about 3$\\mathrm{\\,fb}^{-1}$, collected by the LHCb experiment at centre-of-mass energies of 7 and 8$\\mathrm{\\,TeV}$. The ratio is measured in two regions of the dilepton invariant mass squared, $q^{2}$, to be \\begin{eqnarray*} R_{K^{*0}} = \\begin{cases} 0.66~^{+~0.11}_{-~0.07}\\mathrm{\\,(stat)} \\pm 0.03\\mathrm{\\,(syst)} & \\textrm{for } 0.045 < q^{2} < 1.1~\\mathrm{\\,GeV^2}c^4 \\, , \\\\ 0.69~^{+~0.11}_{-~0.07}\\mathrm{\\,(stat)} \\pm 0.05\\mathrm{\\,(syst)} & \\textrm{for } 1.1\\phantom{00} < q^{2} < 6.0~\\mathrm{\\,GeV^2}c^4 \\, . \\end{cases} \\end{eqnarray*} The corresponding 95.4\\% confidence level intervals are $[0.52, 0.89]$ and $[0.53, 0.94]$. The results, which represent the most precise measurements of $R_{K^{*0}}$ to date, are compatible with the Standard Model expectations at the level of 2.1--2.3 and 2.4--2.5 standard deviations in the two $q^{2}$ regions, respectively.","external_url":"https://arxiv.org/abs/1705.05802","cited_by_count":null,"metadata_source":"pith","metadata_fetched_at":"2026-05-25T19:01:09.230188+00:00","pith_arxiv_id":"1705.05802","created_at":"2026-05-12T07:42:09.727928+00:00","updated_at":"2026-05-25T19:01:09.230188+00:00","title_quality_ok":true,"display_title":"Aaijet al.[LHCb], JHEP08(2017), 055 [arXiv:1705.05802 [hep-ex]]","render_title":"Aaijet al.[LHCb], JHEP08(2017), 055 [arXiv:1705.05802 [hep-ex]]"},"hub":{"state":{"work_id":"a062be69-a4ae-4b49-ae09-ed08df21ebd3","tier":"hub","tier_reason":"10+ Pith inbound or 1,000+ external citations","pith_inbound_count":10,"external_cited_by_count":null,"distinct_field_count":2,"first_pith_cited_at":"2019-06-21T14:53:11+00:00","last_pith_cited_at":"2026-05-09T10:21:32+00:00","author_build_status":"not_needed","summary_status":"needed","contexts_status":"needed","graph_status":"needed","ask_index_status":"not_needed","reader_status":"not_needed","recognition_status":"not_needed","updated_at":"2026-05-29T22:50:40.225110+00:00","tier_text":"hub"},"tier":"hub","role_counts":[{"context_role":"background","n":1},{"context_role":"dataset","n":1}],"polarity_counts":[{"context_polarity":"background","n":1},{"context_polarity":"use_dataset","n":1}],"runs":{},"summary":{},"graph":{},"authors":[]}}