{"id":7797,"date":"2022-06-20T18:29:49","date_gmt":"2022-06-20T16:29:49","guid":{"rendered":"https:\/\/www.lapth.cnrs.fr\/event\/journal-club-a-novel-theoretical-approach-to-rd-through-the-dispersive-matrix-method\/"},"modified":"2022-06-20T18:29:49","modified_gmt":"2022-06-20T16:29:49","slug":"journal-club-a-novel-theoretical-approach-to-rd-through-the-dispersive-matrix-method","status":"publish","type":"tribe_events","link":"https:\/\/www.lapth.cnrs.fr\/en\/event\/journal-club-a-novel-theoretical-approach-to-rd-through-the-dispersive-matrix-method\/","title":{"rendered":"[Journal Club] A novel theoretical approach to $R(D^{(*)})$ through the Dispersive Matrix method"},"content":{"rendered":"<p><strong>Abstract: <\/strong><\/p>\n<p><span style=\"color:#000000\">The ratios $R(D^{(*)})$ are defined as the $tau\/mu$ ratio of the branching fractions&nbsp;of exclusive semileptonic $B to D^{(*)}$ decays. They are a powerful test of Lepton&nbsp;Flavour Universality, one of the pillars of the SM, and are determined by the&nbsp;hadronic Form Factors (FFs) describing the $B to D^{(*)}$ decays. Through the&nbsp;novel Dispersive Matrix (DM) approach, we describe these FFs without assumptions&nbsp;on their functional dependence on the momentum transfer. The DM method is based&nbsp;on the non-perturbative determination of the dispersive bounds due to unitarity and&nbsp;analyticity, and allows to determine in a model-independent way the FFs in the full&nbsp;kinematical range, starting from existing Lattice QCD data which are available only&nbsp;at large momentum transfer. Using the unitarity bands of the FFs, which are thus&nbsp;independent of the experimental determinations of the differential decay widths, we&nbsp;compute new fully-theoretical expectations of the anomalies. Our results read $R(D)&nbsp;= 0.296(8)$ and $R(D^*) = 0.275(8)$, each of which is compatible with the&nbsp;corresponding world average of the measurements at the $sim 1.3 sigma$ level.&nbsp;The origin of the discrepancy between the DM estimates and the HFLAV SM&nbsp;predictions will be also discussed.<\/span><\/p>\n<p>&nbsp;<\/p>\n<p><strong>Zoom link:<\/strong><\/p>\n<p><a href=\"https:\/\/cnrs.zoom.us\/j\/91049381574?pwd=TDZyU3NqT0k4MFk3cUMvc0JuOURCdz09\">https:\/\/cnrs.zoom.us\/j\/91049381574?pwd=TDZyU3NqT0k4MFk3cUMvc0JuOURCdz09<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Abstract: The ratios $R(D^{(*)})$ are defined as the $tau\/mu$ ratio of the branching fractions&nbsp;of exclusive semileptonic $B to D^{(*)}$ decays. They are a powerful test of Lepton&nbsp;Flavour Universality, one of [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"template":"","meta":{"_acf_changed":false,"_tribe_events_status":"","_tribe_events_status_reason":"","footnotes":""},"tags":[],"tribe_events_cat":[14],"class_list":["post-7797","tribe_events","type-tribe_events","status-publish","hentry","tribe_events_cat-upcoming-journal-club","cat_upcoming-journal-club"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.lapth.cnrs.fr\/en\/wp-json\/wp\/v2\/tribe_events\/7797","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.lapth.cnrs.fr\/en\/wp-json\/wp\/v2\/tribe_events"}],"about":[{"href":"https:\/\/www.lapth.cnrs.fr\/en\/wp-json\/wp\/v2\/types\/tribe_events"}],"author":[{"embeddable":true,"href":"https:\/\/www.lapth.cnrs.fr\/en\/wp-json\/wp\/v2\/users\/1"}],"version-history":[{"count":0,"href":"https:\/\/www.lapth.cnrs.fr\/en\/wp-json\/wp\/v2\/tribe_events\/7797\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.lapth.cnrs.fr\/en\/wp-json\/wp\/v2\/media?parent=7797"}],"wp:term":[{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.lapth.cnrs.fr\/en\/wp-json\/wp\/v2\/tags?post=7797"},{"taxonomy":"tribe_events_cat","embeddable":true,"href":"https:\/\/www.lapth.cnrs.fr\/en\/wp-json\/wp\/v2\/tribe_events_cat?post=7797"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}