Publicação
Study of heavy-flavor quarks produced in association with top-quark pairs at $\sqrt{s}=7$ TeV using the ATLAS detector
| dc.contributor.author | ATLAS collaboration (2923 authors) | |
| dc.contributor.author | Aguilar-Saavedra, Juan Antonio | |
| dc.contributor.author | Amor Dos Santos, Susana Patricia | |
| dc.contributor.author | Anjos, Nuno | |
| dc.contributor.author | Cantrill, Robert | |
| dc.contributor.author | Carvalho, João | |
| 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 | Do Valle Wemans, André | |
| 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 | Lopes, Lourenco | |
| dc.contributor.author | Machado Miguens, Joana | |
| dc.contributor.author | Maio, Amélia | |
| dc.contributor.author | Maneira, José | |
| dc.contributor.author | Oliveira, Miguel Alfonso | |
| dc.contributor.author | Onofre, António | |
| dc.contributor.author | Palma, Alberto | |
| dc.contributor.author | Pina, João Antonio | |
| dc.contributor.author | Pinto, Belmiro | |
| dc.contributor.author | Santos, Helena | |
| dc.contributor.author | Saraiva, João | |
| dc.contributor.author | Silva, José | |
| dc.contributor.author | Veloso, Filipe | |
| dc.contributor.author | Wolters, Helmut | |
| dc.date.accessioned | 2019-02-03T22:47:30Z | |
| dc.date.available | 2019-02-03T22:47:30Z | |
| dc.date.issued | 2014-04-21 | |
| dc.date.updated | 2019-02-03T22:47:29Z | |
| dc.description.abstract | Using a sample of dilepton top-quark pair ($t\bar{t}$) candidate events, a study is performed of the production of top-quark pairs together with heavy-flavor (HF) quarks, the sum of $t\bar{t}+b+X$ and $t\bar{t}$+c+X, collectively referred to as $t\bar{t}$ + HF. The data set used corresponds to an integrated luminosity of 4.7 $fb{−1}$ of proton-proton collisions at a center-of-mass energy of 7 TeV recorded by the ATLAS detector at the CERN Large Hadron Collider. The presence of additional HF (b or c) quarks in the $t\bar{t}$ sample is inferred by looking for events with at least three b-tagged jets, where two are attributed to the b quarks from the $t\bar{t}$ decays and the third to additional HF production. The dominant background to $t\bar{t}$ + HF in this sample is $t\bar{t}$+jet events in which a light-flavor jet is misidentified as a heavy-flavor jet. To determine the heavy- and light-flavor content of the additional b-tagged jets, a fit to the vertex mass distribution of b-tagged jets in the sample is performed. The result of the fit shows that 79 ± 14 (stat) ± 22 (syst) of the 105 selected extra b-tagged jets originate from HF quarks, 3 standard deviations away from the hypothesis of zero $t\bar{t}$+ HF production. The result for extra HF production is quoted as a ratio (RHF) of the cross section for $t\bar{t}$ + HF production to the cross section for $t\bar{t}$ production with at least one additional jet. Both cross sections are measured in a fiducial kinematic region within the ATLAS acceptance. RHF is measured to be [6.2±1.1(stat)±1.8(syst)]% for jets with $p_T$ > 25 GeV and |η| < 2.5, in agreement with the expectations from Monte Carlo generators. | |
| dc.description.version | Peer Reviewed | |
| dc.identifier | Phys.Rev. D89 (2014) 072012; DOI 10.1103/PhysRevD.89.072012 | |
| dc.identifier.uri | http://dx.doi.org/10.1103/PhysRevD.89.072012 | |
| dc.identifier.uri | http://hdl.handle.net/10400.26/26415 | |
| dc.language.iso | eng | |
| dc.title | Study of heavy-flavor quarks produced in association with top-quark pairs at $\sqrt{s}=7$ TeV using the ATLAS detector | |
| dc.type | journal article | |
| dspace.entity.type | Publication | |
| rcaap.rights | openAccess | pt |
| rcaap.type | article |