Publication
Search for flavour-changing neutral current top-quark decays $t\to qZ$ in proton-proton collisions at $\sqrt{s}=13$ TeV with the ATLAS detector
| dc.contributor.author | ATLAS collaboration (2869 authors) | |
| dc.contributor.author | Aguilar-Saavedra, Juan Antonio | |
| dc.contributor.author | Amor Dos Santos, Susana Patricia | |
| dc.contributor.author | Araque, Juan Pedro | |
| dc.contributor.author | Castro, Nuno Filipe | |
| dc.contributor.author | Conde Muiño, Patricia | |
| dc.contributor.author | Da Cunha Sargedas De Sousa, Mario Jose | |
| dc.contributor.author | Fiolhais, Miguel | |
| dc.contributor.author | Galhardo, Bruno | |
| dc.contributor.author | Gomes, Agostinho | |
| dc.contributor.author | Gonçalo, Ricardo | |
| dc.contributor.author | Jorge, Pedro | |
| dc.contributor.author | Machado Miguens, Joana | |
| dc.contributor.author | Maio, Amélia | |
| dc.contributor.author | Maneira, José | |
| dc.contributor.author | Oleiro Seabra, Luis Filipe | |
| dc.contributor.author | Onofre, António | |
| dc.contributor.author | Pedro, Rute | |
| dc.contributor.author | Santos, Helena | |
| dc.contributor.author | Saraiva, João | |
| dc.contributor.author | Silva, José | |
| dc.contributor.author | Tavares Delgado, Ademar | |
| dc.contributor.author | Veloso, Filipe | |
| dc.contributor.author | Wolters, Helmut | |
| dc.date.accessioned | 2019-02-05T16:07:17Z | |
| dc.date.available | 2019-02-05T16:07:17Z | |
| dc.date.issued | 2018-07-31 | |
| dc.date.updated | 2019-02-05T16:07:17Z | |
| dc.description.abstract | A search for flavour-changing neutral-current processes in top-quark decays is presented. Data collected with the ATLAS detector from proton-proton collisions at the Large Hadron Collider at a centre-of-mass energy of $\sqrt{s}=13$ TeV, corresponding to an integrated luminosity of 36.1 fb$^{-1}$, are analysed. The search is performed using top-quark pair events, with one top quark decaying through the $t\rightarrow qZ$ $(q = u, c)$ flavour-changing neutral-current channel, and the other through the dominant Standard Model mode $t\rightarrow bW$. Only $Z$ boson decays into charged leptons and leptonic $W$ boson decays are considered as signal. Consequently, the final-state topology is characterized by the presence of three isolated charged leptons (electrons or muons) and at least two jets, one of the jets originating from a $b$-quark. The data are consistent with Standard Model background contributions, and at 95% confidence level the search sets observed (expected) upper limits of $1.7\times10^{-4}$ ($2.4\times10^{-4}$) on the $t\to uZ$ branching ratio and $2.4\times10^{-4}$ ($3.2\times10^{-4}$) on the $t\to cZ$ branching ratio, constituting the most stringent limits to date. | |
| dc.description.version | Peer Reviewed | |
| dc.identifier | JHEP 1807 (2018) 176; DOI 10.1007/JHEP07(2018)176 | |
| dc.identifier.uri | http://dx.doi.org/10.1007/JHEP07(2018)176 | |
| dc.identifier.uri | http://hdl.handle.net/10400.26/27604 | |
| dc.language.iso | eng | |
| dc.title | Search for flavour-changing neutral current top-quark decays $t\to qZ$ in proton-proton collisions at $\sqrt{s}=13$ TeV with the ATLAS detector | |
| dc.type | journal article | |
| dspace.entity.type | Publication | |
| rcaap.rights | openAccess | pt |
| rcaap.type | article |