Search for excited electrons and muons in root s=8 TeV proton-proton collisions with the ATLAS detector

Aad G., Abajyan T., Abbott B., Abdallah J., Khalek S. A. , Abdinov O., ...Daha Fazla

NEW JOURNAL OF PHYSICS, cilt.15, 2013 (SCI İndekslerine Giren Dergi) identifier identifier


The ATLAS detector at the Large Hadron Collider is used to search for excited electrons and excited muons in the channel pp -> ll* -> ll gamma, 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 m(l*). For m(l*) >= 0.8 TeV, the respective upper limits on sigma B(l(*) -> l gamma) are 0.75 and 0.90 fb for the e* and mu* searches. Limits on sigma B are converted into lower bounds on the compositeness scale 3. In the special case where Lambda = m(l*), excited-electron and excited-muon masses below 2.2 TeV are excluded.