Search for excited electrons and muons in $\sqrt{s}$=8 TeV proton-proton collisions with the ATLAS detector

• Autor(a) principal: ATLAS collaboration (2935 authors)
• Data de Publicação: 2013
• Outros Autores: Aguilar-Saavedra, Juan Antonio, Amor Dos Santos, Susana Patricia, Anjos, Nuno, Cantrill, Robert, Carvalho, João, Castro, Nuno Filipe, Conde Muiño, Patricia, Da Cunha Sargedas De Sousa, Mario Jose, Do Valle Wemans, André, Fiolhais, Miguel, Galhardo, Bruno, Gomes, Agostinho, Gonçalo, Ricardo, Jorge, Pedro, Lopes, Lourenco, Machado Miguens, Joana, Maio, Amélia, Maneira, José, Marques, Carlos, Oliveira, Miguel Alfonso, Onofre, António, Palma, Alberto, Pina, João Antonio, Pinto, Belmiro, Santos, Helena, Saraiva, João, Silva, José, Tavares Delgado, Ademar, Veloso, Filipe, Wolters, Helmut
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10400.26/26463

The ATLAS detector at the Large Hadron Collider is used to search for excited electrons and excited muons in the channel pp → ℓℓ* → ℓℓγ, assuming that excited leptons are produced via contact interactions. The analysis is based on 13 fb−1 of pp collisions at a centre-of-mass energy of 8 TeV. No evidence for excited leptons is found, and a limit is set at the 95% credibility level on the cross section times branching ratio as a function of the excited-lepton mass mℓ*. For mℓ* ⩾ 0.8 TeV, the respective upper limits on σB(ℓ* → ℓγ) are 0.75 and 0.90 fb for the e* and μ* searches. Limits on σB are converted into lower bounds on the compositeness scale Λ. In the special case where Λ = mℓ*, excited-electron and excited-muon masses below 2.2 TeV are excluded.