1. WORKING GROUP “NEUTRINO MASS” Valencia, 8/11/2006 Attending people: Oliviero Cremonesi – INFN – CUORE / MARE Flavio Gatti – INFN – MARE Andrea Giuliani – INFN – MARE / CUORE Fabrice Piquemal – CNRS – (Super)NEMO Kai Zuber – Oxford - COBRA

2. Name of the working group Avoid expression “low energy neutrinos” We prefer “neutrino mass scale” or “basic neutrino properties” (depending on the coverage) Coverage of the working group Surely, double beta decay (DBD) single beta decay (SBD) What about neutrino oscillations? (Double Chooz) We believe that the SBD+DBD only would be more appropriate (nuclear physics and nuclear techniques applied to neutrino physics) However, Double Chooz has similar radiopurity issues Much more complicate to organize meetings

3. Analysis and proposed modification for the SBD part p. 52, l. 8, square root missing for the neutrino mass scale formula Quote the systematics problems in T experiments, in particular the so-called Troitzk anomaly Mention the nuclide used in the microcalorimetric technique ( 187 Re), specifying that it has the lowest Q-value in nature Deeper discussion of the microcalorimetric technique, commenting on merits and problems Comment on the systematics problems for both techniques, underlining the differences Mention the MARE experiment and the MARE collaboration Point out that MARE-1 can reach very soon (2-3 y) the present T sensitivity

4. Mention that, after an important R&D phase (5 y), MARE-2 could have the same sensitivity as KATRIN, and that MARE is expandable in principle, unlike KATRIN Analysis and proposed modification for the DBD part DBD is not the only “known” method, but the only “practical” method to reveal the neutrino nature Stress the complementarity of SBD and DBD Stress the experimental complementarity of the various techniques which allow to study several different nuclides, with different approaches to BKG control (tracko-calo vs. calorimeters) Importance of new isotopical separation methods Deadline to take a decision for 1 ton detector: 2012 rather than 2009-2012 Change approach to the quoted sensitivity of the experiments

5. Either a detailed discussion on the chosen matrix elements and background assumptions (tabular form) Or only a rough estimate (~ 0.05 – 0.1 eV or just reference to the mass pattern region) [we prefer] Quote TGV as side experiments for the improvement of the knowledge of nuclear matrix elements Do not confine to EXO / MAJORANA the set of extra-european competitors. Mention the Japanese efforts (MOON, CANDLES) and most of all DBD program in SNO++ A flow diagram with branching points is missing Use IDEA / N4 meetings to produce next road map version, adding the SBD component (update mailing list) Next meeting: IDEA / N4 in Milano-Bicocca, next Friday – a full afternoon will be devoted to that – SBD representative will be present