Charm-baryon semileptonic decays and the strange <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msup><mml:mi mathvariant="normal">?</mml:mi><mml:mo>*</mml:mo></mml:msup></mml:math> resonances: New insights from lattice QCD

Understanding the properties of strange ${\mathrm{\ensuremath{\Lambda}}}^{*}$ baryon resonances is a long-standing and fascinating problem. ${\mathrm{\ensuremath{\Lambda}}}_{c}$ charm-baryon semileptonic weak decays to these are highly sensitive their internal structure can be used test theoretical models. We have performed first lattice-QCD computation form factors governing resonance: ${\mathrm{\ensuremath{\Lambda}}}^{*}(1520)$, which has negative parity spin $3/2$. Here we present resulting Standard Model predictions ${\mathrm{\ensuremath{\Lambda}}}_{c}\ensuremath{\rightarrow}{\mathrm{\ensuremath{\Lambda}}}^{*}(1520){\ensuremath{\ell}}^{+}{\ensuremath{\nu}}_{\ensuremath{\ell}}$ differential integrated decay rates as well angular observables. Furthermore, by combining recent BESIII measurement ${\mathrm{\ensuremath{\Lambda}}}_{c}\ensuremath{\rightarrow}X{e}^{+}{\ensuremath{\nu}}_{e}$ inclusive semipositronic branching fraction [Phys. Rev. Lett. 121, 251801 (2018)] with ${\mathrm{\ensuremath{\Lambda}}}_{c}\ensuremath{\rightarrow}\mathrm{\ensuremath{\Lambda}}{e}^{+}{\ensuremath{\nu}}_{e}$, ${\mathrm{\ensuremath{\Lambda}}}_{c}\ensuremath{\rightarrow}n{e}^{+}{\ensuremath{\nu}}_{e}$, ${\mathrm{\ensuremath{\Lambda}}}_{c}\ensuremath{\rightarrow}{\mathrm{\ensuremath{\Lambda}}}^{*}(1520){e}^{+}{\ensuremath{\nu}}_{e}$ rates, obtain an upper limit on sum fractions all other final states. In particular, this constrains ${\mathrm{\ensuremath{\Lambda}}}_{c}\ensuremath{\rightarrow}{\mathrm{\ensuremath{\Lambda}}}^{*}(1405){e}^{+}{\ensuremath{\nu}}_{e}$ very small, may another hint for molecular ${\mathrm{\ensuremath{\Lambda}}}^{*}(1405)$.