Publicação
A search for an excited muon decaying to a muon and two jets in pp collisions at √ s = 8 TeV with the ATLAS detector
| Resumo: | A new search signature for excited leptons is explored. Excited muons are sought in the channel ${pp}\to \mu {\mu }^{* }\to \mu \mu \ {\rm{jet}}\;{\rm{jet}}$, assuming both the production and decay occur via a contact interaction. The analysis is based on 20.3 fb−1 of pp collision data at a centre-of-mass energy of $\sqrt{s}\;=\;8\;{\rm{TeV}}$ taken with the ATLAS detector at the large hadron collider. No evidence of excited muons is found, and limits are set at the 95% confidence level on the cross section times branching ratio as a function of the excited-muon mass ${m}_{{\mu }^{* }}$. For ${m}_{{\mu }^{* }}$ between 1.3 and 3.0 TeV, the upper limit on $\sigma B({\mu }^{* }\to \mu q\bar{q}$) is between 0.6 and 1 fb. Limits on $\sigma B$ are converted to lower bounds on the compositeness scale Λ. In the limiting case ${\rm{\Lambda }}={m}_{{\mu }^{* }}$, excited muons with a mass below 2.8 TeV are excluded. With the same model assumptions, these limits at larger ${\mu }^{* }$ masses improve upon previous limits from traditional searches based on the gauge-mediated decay ${\mu }^{* }\to \mu \gamma $. |
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| Autores principais: | Onofre, A. |
| Outros Autores: | Castro, Nuno Filipe Silva Fernandes; ATLAS Collaboration |
| Assunto: | excited leptons lepton compositeness leptoquarks |
| Ano: | 2016 |
| País: | Portugal |
| Tipo de documento: | artigo |
| Tipo de acesso: | acesso aberto |
| Instituição associada: | Universidade do Minho |
| Idioma: | inglês |
| Origem: | RepositóriUM - Universidade do Minho |
| Resumo: | A new search signature for excited leptons is explored. Excited muons are sought in the channel ${pp}\to \mu {\mu }^{* }\to \mu \mu \ {\rm{jet}}\;{\rm{jet}}$, assuming both the production and decay occur via a contact interaction. The analysis is based on 20.3 fb−1 of pp collision data at a centre-of-mass energy of $\sqrt{s}\;=\;8\;{\rm{TeV}}$ taken with the ATLAS detector at the large hadron collider. No evidence of excited muons is found, and limits are set at the 95% confidence level on the cross section times branching ratio as a function of the excited-muon mass ${m}_{{\mu }^{* }}$. For ${m}_{{\mu }^{* }}$ between 1.3 and 3.0 TeV, the upper limit on $\sigma B({\mu }^{* }\to \mu q\bar{q}$) is between 0.6 and 1 fb. Limits on $\sigma B$ are converted to lower bounds on the compositeness scale Λ. In the limiting case ${\rm{\Lambda }}={m}_{{\mu }^{* }}$, excited muons with a mass below 2.8 TeV are excluded. With the same model assumptions, these limits at larger ${\mu }^{* }$ masses improve upon previous limits from traditional searches based on the gauge-mediated decay ${\mu }^{* }\to \mu \gamma $. |
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