Cafe neutrino meeting minutes (01/18/10)
Present: E. Benedetto, A. Blondel, F. Dufour, M. Martini, G. Prior, T. Stora, E. Wildner

Agenda:

Outcome of the December 2009 SPC meeting (A. Blondel):
Final version now available (.pdf).
About a year and a half ago the UK neutrino group addressed a series of questions to the CERN council. These questions have been reformulated and forwarded to the SPC who created a committee to look into it. The committee was composed of A. Blondel, P. Dornan, A. Zalewska, R. Aleksan, T. Nakada and F. Swirner. The final report will be made public in March together with the answer from the SPC panel.
First question addressed was on the SPC view on the importance of precise neutrino oscillation measurements and CP violation. It has been responded that as for the hadron sector precise measurements in the lepton sector are very important.
Second question regarded the importance of an International Design Study and whether CERN need to have a more active role. Recalling that IDS is not site specific, the output of the IDS should lead to a CDR and there is a lack of manpower in several critical areas. Especially for the safety and costing CERN could take a more active role. The SPL has a design that fits Neutrino Factory requirements. In term of safety looking at the case of SNS at Oakridge, it uses a Hg loop and it has been demonstrated that because of the high vapor temperature of the mercury, there is Hg vapor in the atmosphere. A study on Hg quantities in the atmosphere has been done at PSI. Hg needs to be solidified to be treated. Pb/Bi despite the fact that it need to be heated, does not present this inconvenient as it solidifies rapidly. Need a detailed study on such issues.
Third question was on which type of other neutrino facilities are technically possible and how CERN can give its contribution. Presenting the graph of CP violation sensitivity as a function of θ₁₃ value. The NF scenario and NF to Finland (2300 km) + INO detector have different sensitivity depending on θ₁₃ (due to MSW dominance effect). A combination of a beta-beam and superbeam is quite competitive and would be a good option. Upgrade of T2K (T2KK) and LBL DUSEL are also reported. PS+SPS infrastructure at CERN can be exploited in a more easy way for BB than for NF. ¹⁸Ne still need to be established. A test experiment would serve here to demonstrate its feasibility. EUROnu ⁸Li/⁸B graph are not here since it needs to be investigated in more details what are the real trade-off and performance of high-Q versus low-Q BB. There is (or will) two superbeams at least in US (Nova and LBL DUSEL) so emphasis should be put on NF and combined BB+Superbeams reach.
Fourth question was on European strategy and it has been affirmed that a coherent R&D strategy should be established even if pursuing different designs.
Conclusion is on recommandation on re-establishing a neutrino research group at CERN in collaboration with theorists and accelerator physicists. The Oct. 1-3 2009 workhop was successful and a consistent effort on doing workshops of this kind has to be pursued. A comprehensive comparable costing of NF, BB and SB has to be done. Radio-protection and safety issues have to be addressed. On the R&D side BB ¹⁸Ne should be investigated and support to MICE given. There is a neutrino beam from PS (through ISR) meeting the WANF beam at CDHS/NOMAD/CHORUS level (proposal from 1980 for a ν_μ to ν_e oscillation) and there is a good potential to do neutrino cross-section measurements. On a long term strategy planning, asusming a staged scenario going through SPL+PS2 it is not realistic to have a neutrino facility before 2020. In the meantime, superbeams and subsequent upgrades will occur. So at long term one needs to concentrate on R&D for beta-beams and NF. The SPL+PS2 approach will be rediscussed and the possible impact on neutrino facilities should be revised.

Detector multiplicity beta-beams versus neutrino factory:
Some reference points on ν_e reconstruction efficiency from WC and NOva plastic Scintillators detectors. About 30% for 2 GeV beam. Can be used at starting point for further discussion. The sensitivity plots for B/Li are being worked on (info last week from M. Mezetto). Elena W. also mentioned the possible lack of the new horn structures for the super-beam/beta-beam combination and Mauro has promised that these things will be included in the picture, also in the plots for the Ne/He case. To be discussed next cafe-neutrino meeting.

Costing workshop at CERN:
Need to discuss next cafe-neutrino meetings in more details about the workshop.

Next meeting: February 1st room 513-1-023 at 10:30 am