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PROSPECTS for detecting a. NEUTRINO MAGNETIC MOMENT with. a TRITIUM SOURCE and BETA-BEAMS. Cristina VOLPE (Institut de Physique Nucléaire ORSAY). Low-energy beta-beams, Possible sites. Neutrino magnetic moment : Present limits. P L A N. Prospects for m n :
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PROSPECTS for detecting a NEUTRINO MAGNETIC MOMENT with a TRITIUM SOURCE and BETA-BEAMS Cristina VOLPE (Institut de Physique Nucléaire ORSAY)
Low-energy beta-beams, Possible sites Neutrino magnetic moment : Present limits P L A N Prospects formn: Tritium source and low-energy beta-beams Conclusions and Perspectives
Low-energy beta-beams C. Volpe, hep-ph/0303222. THE PROPOSAL To exploit the beta-beam concept to produce intense and pure low-energy neutrino beams. PHYSICS POTENTIAL Neutrino-nucleus interaction studies are one of the possible axis of research. e ne C N Neutrino properties.
Possible sites g Detectors Intensities 1012n/s GANIL 1 4p A. Villari (GANIL) 1012-13n/s 1 4p EURISOL 4p and Close detector 109n/s 1-10 GSI H. Weick (GSI) 4p and Close detector CERN 1-100 1012-13n/s Autin et al, J.Phys. (2003). A PROPOSAL for a LOW-ENERGY BETA-BEAM facility.
g l n n W Neutrino magnetic moment mn = 3.2 x 10-19(mn/1 eV)mB Indirect limits : mn < 5. x 10-11mB - Nucleosynthesis Morgan (1981), Fukugita and Yazaki (1987),… mn < 3. x 10-12mB - Stellar Cooling Raffelt (1990),… mn < 1.5-5 x 10-12mB • Supernovae II explosions • (SN1987A) Lattimer and Cooperstein (1988), Goldman et al. (1988), Notzold (1988),…
Neutrino magnetic moment : Direct observation e ne e n n ne g W Neutrino-electron scattering e e WEAK MAGNETIC The presence of a magnetic moment introduces inne-e scattering, a 1/T-like divergence, where T is the electron recoil energy.
Neutrino magnetic moment : Direct limits e ne e ne Present best limits are from reactor experiments. mn < 1.3 x 10-10mB (90 %C.L.) Phys. Rev. Lett.90 (2003) TEXONO Collaboration Kuo-Sheng Reactor Similar limits : JETP Lett. 55 (1992) Kurchatov Reactor JETP Lett. 57 (1993) Rovno Reactor mn < 1.0 x 10-10mB (90 %C.L.) PRESENT LIMIT FROM DIRECT MEASUREMENTS: mn < 1.0 x 10-10mB. MUNU Collaboration, PLB (2003) Bugey Reactor
Prospects formn :Tritium source 3H 3He+e+ne Qb=18.6 KeV 10-11mB 10-12mB Giomataris, hep-ex/ 0303045. Number ofne-eevents with a 200 Mcurie (20 Kg) Tritium source and a 4plow-threshold detector (e.g. TPC or cryogenic). mn = 0 THE LIMIT ofa few x 10-12mB CAN BE OBTAINED. G.C. McLaughlin and C. Volpe, hep-ph/0303222.
Prospects formn :Low-energy Beta-beams ne-eevents with beta-beams (10 15n/s) with a 4p low-thresholddetector. 6He 6Li+e+ne Qb=4. MeV 5 x 10-11mB 5 X 10-11mB 10-10mB mn = 0 10-11mB THE LIMIT ofa few x 10-11mB CAN BE OBTAINED. G.C. McLaughlin and C. Volpe, hep-ph/0303222.
Reactor Experiments 5 x 10-11mB Li and Wong, J.Phys.G28(2002)1453. MUNU R1=5-100 keV R2=0.5-2.MeV 10-10mB Kou-Sheng mn = 0 Uncertainty on the (<3 MeV)n-flux A better understanding of the low-energy (less than 3 MeV) component of the reactor neutrino flux is needed.
Conclusions The direct measurement of a neutrino magnetic moment needs : - intense and well-understood neutrino fluxes; - very low-threshold detectors. Improved limits of a few x 10-12mBand a few x 10-11mBcan be achieved with a 20oMCi tritium source and low-energy beta-beams respectively.
Perspectives “Neutrino-nucleus interactions at a low-energy beta-beam facility” J. Serreau and C. Volpe, in preparation.
WORKSHOP at ECT* (TRENTO, Italy) 18-22 October 2004 “EXPLORING THE IMPACT of NEW NEUTRINO BEAMS” Goals Present status and future projects in neutrino and nuclear physics The feasibility and physics potential of neutrino factories, super- beams, beta-beams and low-energy beta-beams The impact in other fields, among which hadron physics, muon physics, baryogenesis and leptogenesis, nucleosynthesis, … Organizers : C. Volpe (Coordinator) J. Bouchez, M. Lindroos, M. Mezzetto,T. Nillson.