Search for ν μ → ν e oscillations with the OPERA experiment in the CNGS beam

A first result of the search for ν μ → ν e oscillations in the OPERA experiment, located at the Gran Sasso Underground Laboratory, is presented. The experiment looked for the appearance of ν e in the CNGS neutrino beam using the data collected in 2008 and 2009. Data are compatible with the non-oscillation hypothesis in the three-flavour mixing model. A further analysis of the same data constrains the non-standard oscillation parameters θ new and $ \varDelta m_{\mathrm{new}}^2 $ suggested by the LSND and MiniBooNE experiments. For large $ \varDelta m_{\mathrm{new}}^2 $ values (>0.1 eV2), the OPERA 90% C.L. upper limit on sin2(2θ new) based on a Bayesian statistical method reaches the value 7.2 × 10−3.