Séminaire spécialisé

jeudi 29 janvier 2015 à 11:30


Latest results from NEMO-3 and status of SuperNEMO

Alberto Remoto

Laboratoire d’Annecy-le-Vieux de Physique des Particules

The NEMO-3 experiment performed precise measurement of the double beta decay and searched for the neutrino-less double beta decay on seven isotopes, among which \(^{100}\)Mo and \(^{82}\)Se were the dominant ones. No evidence of 0\(\nu\beta\beta\) events has been found with an exposure of 34.7 kg×y of \(^{100}\)Mo, providing a limit for the light Majorana neutrino mass mechanism of \(T^{0\nu\beta\beta}_{1/2}\gt\) 1.1 × 10\(^{24}\) y (90 % C.L.) which corresponds to an effective neutrino mass of \(|m_{\beta\beta}| \lt\) 0.3 - 0.9 eV, depending from the Nuclear Matrix Element considered. The same experimental technique has been adopted for the next generation experiment called SuperNEMO. The new detector has a modular design with the capability to measure different isotopes at the same time, \(^{48}\)Ca, \(^{82}\)Se and \(^{150}\)Nd are currently under consideration. With 20 detection modules observing for 5 years 100 kg of \(^{82}\)Se, the expected sensitivity should reach \(T^{0\nu}_{1/2}\gt\) 10\(^{26}\) y (\(|m_{\beta\beta}|\lt\) 0.04 - 0.10 eV). In order to demonstrate the feasibility of the full experiment, the first step is the imminent construction of a first demonstrator module containing 7 kg of \(^{82}\)Se. With an expected sensitivity of \(T^{0\nu}_{1/2}\gt\) 6.6 × 10\(^{24}\) y (\(|m_{\beta\beta}|\lt\) 0.2 - 0.4 eV) after 2.5 y, the demonstrator module will also be able to perform a competitive measurement. After a brief overview on the physics of the double beta decay and the current experimental scenario, the seminar will focus on the recent results obtained by NEMO3 and on the status of SuperNEMO. A particular attention will be given to the imminent construction of the first demonstrator module.