We present a study of the ${X}^{\ifmmode\pm\else\textpm\fi{}}(5568)$ using semileptonic decays of the ${B}_{s}^{0}$ meson using the full run II integrated luminosity of $10.4\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ in proton-antiproton collisions at a center of mass energy of 1.96 TeV collected with the D0 detector at the Fermilab Tevatron Collider. We report evidence for a narrow structure, ${X}^{\ifmmode\pm\else\textpm\fi{}}(5568)$, in the decay sequence ${X}^{\ifmmode\pm\else\textpm\fi{}}(5568)\ensuremath{\rightarrow}{B}_{s}^{0}{\ensuremath{\pi}}^{\ifmmode\pm\else\textpm\fi{}}$ where ${B}_{s}^{0}\ensuremath{\rightarrow}{\ensuremath{\mu}}^{\ensuremath{\mp}}{D}_{s}^{\ifmmode\pm\else\textpm\fi{}}\mathrm{X}$, ${D}_{s}^{\ifmmode\pm\else\textpm\fi{}}\ensuremath{\rightarrow}\ensuremath{\phi}{\ensuremath{\pi}}^{\ifmmode\pm\else\textpm\fi{}}$ which is consistent with the previous measurement by the D0 Collaboration in the hadronic decay mode, ${X}^{\ifmmode\pm\else\textpm\fi{}}(5568)\ensuremath{\rightarrow}{B}_{s}^{0}{\ensuremath{\pi}}^{\ifmmode\pm\else\textpm\fi{}}$ where ${B}_{s}^{0}\ensuremath{\rightarrow}J/\ensuremath{\psi}\ensuremath{\phi}$. The mass and width of this state are measured using a combined fit of the hadronic and semileptonic data, yielding $m={5566.9}_{\ensuremath{-}3.1}^{+3.2}{(\mathrm{stat})}_{\ensuremath{-}1.2}^{+0.6}(\mathrm{syst})\text{ }\text{ }\mathrm{MeV}/{c}^{2}$, $\mathrm{\ensuremath{\Gamma}}={18.6}_{\ensuremath{-}6.1}^{+7.9}{(\mathrm{stat})}_{\ensuremath{-}3.8}^{+3.5}(\mathrm{syst})\text{ }\text{ }\mathrm{MeV}/{c}^{2}$ with a significance of $6.7\ensuremath{\sigma}$.
Tópico:
Particle physics theoretical and experimental studies