Speaker
Louis Lello
(University of Pittsburgh)
Description
Oscillations of light Dirac and Majorana sterile neutrinos with $m_s \simeq eV$ produced in meson decays are suppressed through decoherence aspects arising from lifetime effects of the decaying mesons and the stopping distance of the charged lepton in short baseline experiments. We obtain the transition probability from production to detection via charged current interactions including these decoherence effects for 3+1 and 3+2 scenarios and the impact of these effects on the determination of mixing angles, mass differences and CP-violating amplitudes. We argue that decoherence effects are important in current short baseline accelerator experiments, leading to an underestimate of masses, mixing and CP-violating angles. At MiniBooNE/SciBooNE we estimate that these effects lead to an $\sim 15%$ underestimate for sterile neutrino masses $m_s \gtrsim 3 \,\mathrm{eV}$. We argue that reactor and current short baseline accelerator experiments are fundamentally different and suggest that in future high intensity experiments with neutrinos produced from $\pi,K$ decay at rest, stopping the charged leptons on distances much smaller than the decay length of the parent meson suppresses considerably these decoherence effects.
Author
Louis Lello
(University of Pittsburgh)
