Observation of spin correlation in tt̄ events from pp collisions at √s = 7 TeV Using the ATLAS detector
A measurement of spin correlation in tt̄ production is reported using data collected with the ATLAS detector at the LHC, corresponding to an integrated luminosity of 2.1 fb⁻¹. Candidate events are selected in the dilepton topology with large missing transverse energy and at least two jets. The diffe...
| Autores: | , , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2012 |
| País: | Argentina |
| Institución: | Universidad Nacional de La Plata |
| Repositorio: | SEDICI (UNLP) |
| Idioma: | inglés |
| OAI Identifier: | oai:sedici.unlp.edu.ar:10915/131228 |
| Acceso en línea: | http://sedici.unlp.edu.ar/handle/10915/131228 |
| Access Level: | acceso abierto |
| Palabra clave: | Ciencias Exactas Física Top quarks Experimental tests Inclusive production with identified leptons, photons, or other nonhadronic particles |
| Sumario: | A measurement of spin correlation in tt̄ production is reported using data collected with the ATLAS detector at the LHC, corresponding to an integrated luminosity of 2.1 fb⁻¹. Candidate events are selected in the dilepton topology with large missing transverse energy and at least two jets. The difference in azimuthal angle between the two charged leptons in the laboratory frame is used to extract the correlation between the top and antitop quark spins. In the helicity basis the measured degree of correlation corresponds to A<sub>helicity</sub> = 0.40<sup>+0:09</sup><sub>-0.08</sub>, in agreement with the next-to-leading-order standard model prediction. The hypothesis of zero spin correlation is excluded at 5.1 standard deviations. |
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