Searching the inclusive ℓγET+b -quark signature for radiative top quark decay and non-standard-model processes

Le résumé fourni par la source

We compare the inclusive production of events containing a lepton ($\ensuremath{\ell}$), a photon ($\ensuremath{\gamma}$), significant transverse momentum imbalance (${\mathrm{E\ensuremath{\llap{\not\;}}}}_{T}$), and a jet identified as containing a $b$-quark, to SM predictions. The search uses data produced in proton-antiproton collisions at $\sqrt{s}=1.96\text{ }\text{ }\mathrm{TeV}$ corresponding to $1.9\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ of integrated luminosity taken with the CDF detector. We find 28 $\ensuremath{\ell}\ensuremath{\gamma}b{\mathrm{E\ensuremath{\llap{\not\;}}}}_{T}$ events versus an expectation of ${31.0}_{\ensuremath{-}3.5}^{+4.1}$ events. If we further require events to contain at least three jets and large total transverse energy, the largest SM source is radiative top-quark pair production, $t\overline{t}+\ensuremath{\gamma}$. In the data we observe 16 $t\overline{t}\ensuremath{\gamma}$ candidate events versus an expectation from SM sources of ${11.2}_{\ensuremath{-}2.1}^{+2.3}$. Assuming the difference between the observed number and the predicted non-top-quark total of ${6.8}_{\ensuremath{-}2.0}^{+2.2}$ is due to SM top-quark production, we estimate the $t\overline{t}\ensuremath{\gamma}$ cross section to be $0.15\ifmmode\pm\else\textpm\fi{}0.08\text{ }\text{ }\mathrm{pb}$.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.