This Letter presents the first search for a heavy particle decaying into an e(+/-)mu(-/+) final state in root s = 7 TeV pp collisions at the LHC. The data were recorded by the ATLAS detector during 2010 and correspond to a total integrated luminosity of 35 pb(-1).
No excess above the standard model background expectation is observed. Exclusions at 95% confidence level are placed on two representative models.
In an R-parity violating supersymmetric model, tau sneutrinos with a mass below 0.75 TeV are excluded, assuming all R-parity violating couplings are zero except lambda(311)'' = 0.11 and lambda(312) = 0.07. In a lepton flavor violating model, a Z''-like vector boson with masses of 0.70-1.00 TeV and corresponding cross sections times branching ratios of 0.175-0.183 pb is excluded.
These results extend to higher mass R-parity violating sneutrinos and lepton flavor violating Z''s than previous constraints from the Tevatron.