A search for excited electrons produced in pp collisions at s√ = 13 TeV via a contact interaction qq¯→ee∗ is presented. The search uses 36.1 fb−1 of data collected in 2015 and 2016 by the ATLAS experiment at the Large Hadron Collider. Decays of the excited electron into an electron and a pair of quarks (eqq¯) are targeted in final states with two electrons and two hadronic jets, and decays via a gauge interaction into a neutrino and a W boson (νW) are probed in final states with an electron, missing transverse momentum, and a large-radius jet consistent with a hadronically decaying W boson. No significant excess is observed over the expected backgrounds. Upper limits are calculated for the pp→ee∗→eeqq¯ and pp→ee∗→eνW production cross sections as a function of the excited electron mass me∗ at 95% confidence level. The limits are translated into lower bounds on the compositeness scale parameter Λ of the model as a function of me∗. For me∗<0.5 TeV, the lower bound for Λ is 11 TeV. In the special case of me∗=Λ, the values of me∗<4.8 TeV are excluded. The presented limits on Λ are more stringent than those obtained in previous searches.

Search for excited electrons singly produced in proton–proton collisions at at s√ = 13 TeV with the ATLAS experiment at the LHC

De Castro , S.;Fabbri , L.;Gabrielli , A.;Rinaldi , L.;Semprini Cesari , N.;Sioli , M.;Villa , M.;Zoccoli , A.;Bellagamba , L.;Boscherini , D.;Bruni , A.;D’Amen , G.;Giacobbe , B.;Polini , A.;Sbarra , C.;Franchini , M.;Mengarelli , A.;Romano , M.;Valentinetti , S.;Alberghi , G. L.;Biondi , S.;Fabbri , F.;Lasagni Manghi , F;Massa , L.;Ucchielli , G.;Vittori , C.;Alfonsi , F:;Cabras , G.;Giangiacomi , N.;
2019

Abstract

A search for excited electrons produced in pp collisions at s√ = 13 TeV via a contact interaction qq¯→ee∗ is presented. The search uses 36.1 fb−1 of data collected in 2015 and 2016 by the ATLAS experiment at the Large Hadron Collider. Decays of the excited electron into an electron and a pair of quarks (eqq¯) are targeted in final states with two electrons and two hadronic jets, and decays via a gauge interaction into a neutrino and a W boson (νW) are probed in final states with an electron, missing transverse momentum, and a large-radius jet consistent with a hadronically decaying W boson. No significant excess is observed over the expected backgrounds. Upper limits are calculated for the pp→ee∗→eeqq¯ and pp→ee∗→eνW production cross sections as a function of the excited electron mass me∗ at 95% confidence level. The limits are translated into lower bounds on the compositeness scale parameter Λ of the model as a function of me∗. For me∗<0.5 TeV, the lower bound for Λ is 11 TeV. In the special case of me∗=Λ, the values of me∗<4.8 TeV are excluded. The presented limits on Λ are more stringent than those obtained in previous searches.
De Castro , S. ; Fabbri , L. ; Gabrielli , A. ; Rinaldi , L. ; Semprini Cesari , N. ; Sioli , M. ; Villa , M. ; Zoccoli , A. ; Bellagamba , L. ; Boscherini , D. ; Bruni , A. ; Bruni , G. ; D’Amen , G. ; Giacobbe , B. ; Polini , A. ; Sbarra , C. ; Sidoti , A. ; Spighi , R. ; Franchini , M. ; Mengarelli , A. ; Romano , M. ; Valentinetti , S. ; Alberghi , G. L. ; Biondi , S. ; Fabbri , F. ; Lasagni Manghi , F; Massa , L. ; Ucchielli , G. ; Vittori , C. ; Alfonsi , F: ; Cabras , G. ; Cervelli , A. ; Giangiacomi , N. ; Negrini , M. ; ATLAS collaboration
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Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/11585/723995
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