Séminaires LLR

Neutrino-nucleus interactions: from nuclear dynamics to neutrino oscillations

par Marco Martini (CEA/DAM/DIF)

Europe/Paris
Seminar room (LLR)

Seminar room

LLR

Description
Fifteen years after the discovery of the neutrino oscillation, neutrino physics is now entering in the precision era. After the recent measurements of theta13 at accelerator and reactor experiments, the next goals are the determination of the mass hierarchy (i.e. the ordering of the neutrino mass eigenstates) and of the leptonic CP phase, which will require control of systematic errors at an unprecedented level of accuracy. One of the major systematic in the present and future accelerator-based neutrino oscillation experiments is related to the knowledge of the neutrino-nucleus cross sections since in these experiments nuclear targets (such as C, O, Ar and Fe) are involved. The knowledge of these cross sections is crucial in particular for the determination of the neutrino energy which enters the expression of the oscillation probability, since this energy is reconstructed from the final states of the neutrino-nucleus reaction. A theoretical approach, developed in collaboration with researchers of the IPN Lyon, treating the open channels in the few-GeV region, i.e. the quasielastic, the pion production and the multinucleon emission, is presented. Special emphasis is devoted to the multinucleon emission channel, which turned to be crucial to explain the unexpected behavior of the charged current quasielastic measurement performed by the MiniBooNE experiment. Up to last year, this channel was not included in the generators used for the analyses of the neutrino cross sections and oscillations experiments. The impact of the multinucleon emission channel on the neutrino energy reconstruction procedure and on the neutrino oscillation results will be discussed in detail. The experimental projects aiming to improve our knowledge of the neutrino-nucleus cross sections, hence to reduce the systematic errors in the oscillation analysis, will be discussed in the final part of the talk paying particular attention to the T2K near detector (ND280) and to the WAGASCI project in which the CEA/Irfu/SPP and the LLR neutrino groups, members of the P2IO network, are involved.
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