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n. n -NUCLEUS INTERACTIONS. OPEN QUESTIONS and FUTURE PROJECTS. Cristina VOLPE Institut de Physique Nucléaire Orsay, France. n. I. Motivation. II. Present Status, Open Questions. P L A N. III. Future Projects: Low-energy Beta-beams. IV. Conclusions and Perspectives. ATMOSPHERE.
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n n-NUCLEUS INTERACTIONS OPEN QUESTIONS andFUTURE PROJECTS Cristina VOLPE Institut de Physique Nucléaire Orsay, France
n I. Motivation II. Present Status, Open Questions P L A N III. Future Projects: Low-energy Beta-beams IV. Conclusions and Perspectives
ATMOSPHERE SUN, REACTORS 500 (MeV) 10 50 100 1000 ACCELERATORS SUPERNOVAE n-NUCLEUS INTERACTIONS Different sources produce neutrinos whose energies span various orders of magnitude. Neutrino-Energy We will focuson the low neutrino impinging energies. Cristina Volpe (IPN Orsay)
Motivation:n-Detector Response n ne C 12C N e Detector Nuclei are often used as neutrino detectors in, e.g. solar experiments, supernova observatories or oscillation measurements. EXAMPLE Oscillation measurements THE INTERPRETATION RELIES UPON PRECISE KNOWLEDGE OF THE CROSS SECTIONS. Cristina Volpe (IPN Orsay)
neutrino capture ! Z+1 PROTONS neutron capture Z N-1 N+1 N b-decay NEUTRONS neutron-rich (exotic) nuclei. Understanding Nucleosynthesis The site where the heavy elements are synthetized is not known. Supernova type II explosions: 99 % of the energy is emitted as neutrinos. Calculations of abundances. n-NUCLEUS INTERACTIONS ARE NEEDED. Cristina Volpe (IPN Orsay)
ATMOSPHERE SUN,REACTOR 500 10 50 (MeV) 100 1000 ACCELERATORS SUPERNOVA n-Nucleus Interactions: Present status Neutrinos probe nuclei over a wide energy range. Nuclear Degrees of Freedom Nucleon Degrees of Freedom n-Energy EFT, Microscopic Approaches (RPA, Shell Model), EPT,… Fermi Gas Experimental data areveryscarce (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 ! Cristina Volpe (IPN Orsay)
N m nm b B b C Constraints and Challenges From other weak processes : b-decay Very low momentum transfer (a few MeVs) m-capture Low momentum transfer (about 100 MeV) EXAMPLE From model-independent sum-rules, for some states. 2+ 1- BUT… Neutrinos can transfer a lot of energy to a nucleus. 3- 1- 1+ nm+ 12C12N+m- 0+ N C LARGE SCALE CALCULATIONS ARE REQUIRED. Cristina Volpe (IPN Orsay)
The contribution to the total cross section increases for increasing impinging neutrino energy. no experimental information is available. ne+ 208Pb208Bi+ e- EXAMPLE <Ene>= 15 MeV 2+ 1- 3- 1- 30 MeV 1+ 0+ Bi Pb 50 MeV NEUTRINOS AS a PROBE for NUCLEAR STRUCTURE STUDIES. Cristina Volpe (IPN Orsay)
(Other) Open Questions Neutrino-Deuteron (SNO) EFT : the best known reaction (a few percent uncertainties), a precise knowledge of L1A is necessary(e.g. for the pp reaction in the Sun). Neutrino-Carbon But the cross sections with neutrinos from pion decay in flight is not yet fully understood… Neutrino-Lead A precise measurement of ds/dEe of the electrons emitted in CC events would be very useful. Strange quark contribution to the form factors. Cristina Volpe (IPN Orsay)
n Is there a possibility to perform systematic neutrino-nucleus interaction studies at low energies?
ORLAND : OAK RIDGELABORATORY forNEUTRINODETECTORS (2000) Low-EnergyBETA-BEAMS! Neutrino beams can be produced with enmne mnm m p CONVENTIONAL METHODS: STRATEGIES 6He6Li+ e- + ne THE BETA-BEAM CONCEPT: n n Lorentz boost 6He 6He Q 1/ g high Zucchelli, PLB 2002 Pure neutrino beams produced by boosting ions which decay through beta-decay. Cristina Volpe (IPN Orsay)
n PHYSICS POTENTIAL n 6He 6He boost Neutrino-nucleus interaction studies. n 6He Neutrino properties, like n magnetic moment. Low-energyBeta-beams Volpe, Journ. Phys. G. 30 (2004). THE PROPOSAL 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)
Possible Sites Many laboratories will produce intense exotic ion beams in the future. g Intensities Storage Ring Detector 1012n/s GANIL 1 4p 4p and Close detector 1-10 109n/s GSI 1-100 1012-14n/s CERN CERN A UNIQUE SITE FOR THE n-INTENSITIES & ENERGIES. Cristina Volpe (IPN Orsay)
If a high-energy beta-beam is built… Close Detector EURISOL SPS Storage Ring Production and acceleration of exotic ions Baseline Scenario at CERN PS B. Autin et al, J.Phys. G. UNO One of the possible scenarios : CP VIOLATION, PROTON DECAY, SUPERNOVA n. Geneve 130 km Italy It can be part of it. Cristina Volpe (IPN Orsay)
n-Nucleus Interaction Rates Neutrino Fluxes n n J. Serreau and C. Volpe, hep-ph/0403293. g <En>~2gQb/2 Mass (tons) Small Ring Large Ring Events per year for g=14 35 ne+ D 1956 25779 952 ne+ 16O 82645 9453 360 ne+ 208Pb 103707 7922 Small Ring :Lss = 150 m, Ltot = 450mLarge Ring :Lss = 2.5 km, Ltot =7.5 km INTERESTING INTERACTION RATES CAN BE OBTAINED. Cristina Volpe (IPN Orsay)
The n-Magnetic Moment: Prospects ne-eevents with low-energy beta-beams (10 15n/s) and a 4p low threshold detector. g l n n 5 X 10-11mB W PRESENT DIRECT LIMIT: mn< 1.0 x 10-10mB. e T ne e mn introduces a 1/T-like divergence. ne n 10-11mB 6He Qb=4. MeV mn=0 THE LIMIT CAN BE IMPROVED BY ONE ORDER of MAGNITUDE . G.C. McLaughlin and C. Volpe, Phys. Lett. B 591 (2004).
NUCLEAR PHYSICS e ne C N Supernovae, Nucleosynthesis Neutrino experiments STANDARD MODEL and BEYOND ASTROPHYSICS Neutrino-Nucleus Interactions A topic of current great interest for various domains of physics. 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. A rich physics program can be performed. Conclusions and Perspectives Just approved ! More to come…