1. -NUCLEUS INTERACTIONS OPEN QUESTIONS and FUTURE PROJECTS Cristina VOLPE Institut de Physique Nucléaire Orsay, France

2. I. Motivation II. Present Status, Open Questions III. Future Projects: Low-energy Beta-beams IV. Conclusions and Perspectives PLANPLAN

3. Neutrino-Energy We will focus on the low neutrino impinging energies. - NUCLEUS INTERACTIONS Different sources produce neutrinos whose energies span various orders of magnitude. SUPERNOVAE ATMOSPHERE SUN, REACTORS ACCELERATORS 10 50 1001000 (MeV) 500 Cristina Volpe (IPN Orsay)

4. Nuclei are often used as neutrino detectors in, e.g. solar experiments, supernova observatories or oscillation measurements. Motivation : - Detector Response Oscillation measurements THE INTERPRETATION RELIES UPON PRECISE KNOWLEDGE OF THE CROSS SECTIONS. C N e 12 C Detector e EXAMPLEEXAMPLE Cristina Volpe (IPN Orsay)

5. Understanding Nucleosynthesis The site where the heavy elements are synthetized is not known. Calculations of abundances. Supernova type II explosions: 99 % of the energy is emitted as neutrinos. -NUCLEUS INTERACTIONS ARE NEEDED. neutrino capture ! N N+1N-1 Z Z+1 neutron capture  -decay NEUTRONS PROTONS neutron-rich (exotic) nuclei. Cristina Volpe (IPN Orsay)

6. Nuclear Degrees of Freedom Nucleon Degrees of Freedom Fermi Gas SUPERNOVA ATMOSPHERE SUN,REACTOR ACCELERATORS 10 50 1001000 (MeV) 500 EFT, Microscopic Approaches (RPA, Shell Model), EPT,… -Energy Neutrinos probe nuclei over a wide energy range. Cristina Volpe (IPN Orsay) -Nucleus Interactions: Present status Experimental data are very scarce ( deuteron and iron, carbon). Theoretical predictions are absolutely necessary. The interpolation between these two regimes as well as the extrapolation from stable to exotic nuclei are needed !

7. Constraints and Challenges Very low momentum transfer (a few MeVs)  -decay Low momentum transfer (about 100 MeV)  - capture BUT… From model-independent sum-rules, for some states. EXAMPLEEXAMPLE C N B     C N 0+0+ 1+1+ 1-1- 1-1- 2+2+ 3-3- Neutrinos can transfer a lot of energy to a nucleus.  + 12 C 12 N +  - LARGE SCALE CALCULATIONS ARE REQUIRED. Cristina Volpe (IPN Orsay) From other weak processes :

8. = 15 MeV 30 MeV 50 MeV e + 208 Pb 208 Bi + e - Pb Bi 0+0+ 1+1+ 1-1- 1-1- 2+2+ 3-3- EXAMPLEEXAMPLE NEUTRINOS AS a PROBE for NUCLEAR STRUCTURE STUDIES. The contribution to the total cross section increases for increasing impinging neutrino energy. Cristina Volpe (IPN Orsay) no experimental information is available.

9. Neutrino-Lead A precise measurement of d  /dE e of the electrons emitted in CC events would be very useful. (Other) Open Questions Neutrino-Deuteron (SNO) EFT : the best known reaction (a few percent uncertainties), a precise knowledge of L 1A is necessary (e.g. for the pp reaction in the Sun). Cristina Volpe (IPN Orsay) Strange quark contribution to the form factors. But the cross sections with neutrinos from pion decay in flight is not yet fully understood… Neutrino-Carbon

10. Is there a possibility to perform systematic neutrino-nucleus interaction studies at low energies?

11. STRATEGIES Neutrino beams can be produced with    e  e ORLAND : OAK RIDGE LABORATORY for NEUTRINO DETECTORS (2000) THE BETA-BEAM CONCEPT : Zucchelli, PLB 2002 Lorentz boost  1/ high  Low-Energy BETA-BEAMS ! 6 He CONVENTIONAL METHODS : 6 He 6 Li + e - + e Pure neutrino beams produced by boosting ions which decay through beta-decay. Cristina Volpe (IPN Orsay)

12. THE PROPOSAL Volpe, Journ. Phys. G. 30 (2004). Neutrino properties, like magnetic moment. Low-energy Beta-beams To exploit the beta-beam concept to produce intense and pure low-energy neutrino beams. A „BETA-BEAM“ FACILITY FOR LOW-ENERGY NEUTRINOS. Cristina Volpe (IPN Orsay) PHYSICS POTENTIAL Neutrino-nucleus interaction studies. boost 6 He 6 He

13. Cristina Volpe (IPN Orsay) CERN GANIL Intensities Detector  10 12 /s 1 44 10 12-14 /s 1- 100 4  and Close detector Many laboratories will produce intense exotic ion beams in the future. Possible Sites GSI 10 9 /s 1-10 Storage Ring CERN A UNIQUE SITE FOR THE -INTENSITIES & ENERGIES.

14. PS Storage Ring SPS B. Autin et al, J.Phys. G. Geneve Italy 130 km UNO Production and acceleration of exotic ions Baseline Scenario at CERN If a high-energy beta-beam is built… EURISOL Cristina Volpe (IPN Orsay) CP VIOLATION, PROTON DECAY, SUPERNOVA. Close Detector One of the possible scenarios : It can be part of it.

15. -Nucleus Interaction Rates J. Serreau and C. Volpe, hep-ph/0403293. Small RingLarge Ring 25779 82645 1037077922 9453 1956 e + 208 Pb e + 16 O e + D Events per year for  =14 Small Ring : L ss = 150 m, L tot = 450m Large Ring : L ss = 2.5 km, L tot =7.5 km Neutrino Fluxes INTERESTING INTERACTION RATES CAN BE OBTAINED. Cristina Volpe (IPN Orsay) Mass (tons)  <E  ~2  Q  /2 35 952 360

16. The -Magnetic Moment: Prospects G.C. McLaughlin and C. Volpe, Phys. Lett. B 591 (2004). THE LIMIT CAN BE IMPROVED BY ONE ORDER of MAGNITUDE. PRESENT DIRECT LIMIT:  < 1.0 x 10 -10  B. Q   MeV 6 He e e e e  introduces a 1/T-like divergence. T 10 -11  B 5 X 10 -11  B e -e events with low-energy beta-beams (10 15 /s) and a 4  low threshold detector.  =0  W l

17. Conclusions and Perspectives Neutrino-Nucleus Interactions A topic of current great interest for various domains of physics. Supernovae, Nucleosynthesis Neutrino experiments STANDARD MODEL and BEYOND ASTROPHYSICS NUCLEAR PHYSICS C N e e

18. More to come… Conclusions and Perspectives Low-energy Beta-beams A facility producing low-energy neutrinos. CERN seems a unique site. The feasibility study will be performed, jointly to the high energy facility, within the EURISOL Design Study. Just approved ! A rich physics program can be performed.