Core-collapse supernova neutrinos, neutrino properties and… CP violation Cristina VOLPE (Institut de Physique Nucléaire Orsay, FRANCE)

Nuclear physics double-beta decay, -nucleus interaction,… Neutrino Physics Astrophysics and cosmology Solar , SNII, UHE, BBN, LSS, leptogenesis, … Particle physics Standard Model and beyond AN EXCITING INTERDISCIPLINARY DOMAIN !

THE first OBSERVATION of SOLAR e From fusion reactions, like p+p  2 H+e + + e 1970 the detector Homestake mine (South Dakota) 600 tons of C 2 Cl 4 e + 37 Cl 37 Ar + e - « We observe much less neutrinos than we expect. » « THE SOLAR NEUTRINO PUZZLE » THE IMPORTANT DISCOVERY OF NEUTRINO OSCILLATIONS.

THE  CP violating PHASE INTRODUCES A - ASYMMETRY. L  3  e  1  12  23  13 1  3 e   The two basis are related by a unitary matrix, called the Maki-Nakagawa-Sakata- Pontecorvo (MNSP) matrix, which is the analog of the Cabibbo-Kobayashi- Maskawa (CKM) matrix for quarks.  23  13  12 THE OSCILLATION PARAMETERS

PLAN II. Supernova neutrinos and neutrino properties Conclusions and Pespectives I.Core-collapse supernova neutrinos : A brief overview

Totani et al., Astr.. J t (s) I.Core-collapse SUPERNOVAE collapse e burst cooling NEUTRINOS FOLLOW CLOSELY THE EXPLOSION MECHANISM, not fully understood. massive stars, intense source (99 % of the energy) of e, , , e, , , during the gravitational collapse. fluxes at emission : Fermi-Dirac distributions

SN1987AEVENTSSN1987AEVENTS R. Davis and M. Koshiba, 2002 Nobel Prize with R. Giacconi SN1987A

FUTURE EXPERIMENTS IMPORTANT DISCOVERY FOR SUPERNOVA AND NEUTRINO PHYSICS. I.To measure the neutrino luminosity curve from a future (extra)galactic explosion. SK 9000 MEMPHYS EVENTS II. To measure the relic neutrino background from past supernova explosions. Theoretical predictions close to the present experimental limit (1.2 anti- e /cm2/s from Super-Kamiokande). New observatories of large (megaton) size are under study (water Cherenkov, scintillator, liquid argon technologies are considered). A demand for a design study (LAGUNA) submitted within FP7. Such observatories can observe far explosion (much more frequent) and reach the sensitivity to observe relic neutrinos.

Neutrino Astronomy « To use stars and the Universe for the study of fundamental properties. » The philosophy… Neutrinos mass hierarchy ? the mixing angle  13 ? Majorana or Dirac ? the magnetic moment ? … Core-collapse supernovae neutrino propagation in the star luminosities, spectra, time distribution of the emitted neutrinos nucleosynthesis (r-process) …

Earth detection PROPAGATION IN THE STAR The Mykheyev-Smirnov-Wolfenstein (MSW effect, ’78 and ’86) : V (  ) G F  e. e e e e W m2m2 vacuum high   1 coeur core  1 fluxes at emission  e   10 A = -  m 2 /4E cos 2  B = -  m 2 /4E sin 2  A potential is introduced due to the coupling with matter. Neutrino properties modify the possible signal in SNII observatories on earth.

EXAMPLE : The signal produced in a lead observatory (20 MeV) (10 MeV) ! II. INFORMATION on  13 Engel, McLaughlin,Volpe, PRD67(2003) Present limit : sin 2 2  13 < 0.1 Two neutron events depend on the electron neutrino temperature, and therefore on the  13 angle. HANO PROJECT JUST SUBMITTED AT SNOLAB.

« Beta-beam » a new method to produce pure and intense neutrino beams based on the beta-decay of boosted radioactive ions. The main goal is to search for CP violation. C.Volpe, J Phys G 30 (2004). A proposal to establish a facility for the production of intense and pure low energy neutrino beams ( MeV). boost 6 He close detector PS SPS EURISOLEURISOL storage ring BASELINE NEW AXIS for EURISOL, FEASIBILITY STUDY WITHIN THE FP6 BETA-BEAMS DE BASSE ENERGIE Zucchelli, PLB 2002

Physics potential of low energy beta-beams nuclear astrophysics applications Volpe J Phys G 2004 Jachowicz and McLaughlin PRL 2006 Jachowicz et al in preparation 2007 …. fundamental interaction studies ( Weinberg angle, CVC test, , etc… ): McLaughlin and Volpe, PLB 2004, Balantekin et al PLB 2006 Balantekin et al PRD 2006 Bueno et al PRC 2006 Barranco et al 2006 Amanik et al PRD 2007 …. neutrino-nucleus interaction Volpe J Phys G 2004 Serreau and Volpe PRC 2004 McLaughlin PRC 2004 Lazauskas and Volpe NPA 2007 …. Off-axis options : Lazauskas et al PRD 2007, Amanik et al PRC C.Volpe, Review on “Beta-beams”, J. Phys. G34, R1 (2007), hep-ph/

The possible existence of CP violation in the lepton sector is a crucial issue that will be addressed by « third generation » experiments (super-beams, beta-beams, neutrino factories). Can we use supernova neutrinos to learn about CP violation in the lepton sector ? Jérome Gava’s PhD Thesis

A.B. Balantekin, J. Gava, C. Volpe, arXiv: SUPERNOVA  and CP violation Analytically, we have demonstrated that : - if the  and  fluxes differ at emission (ex. physics beyond the Standard Model), there are significant effects from the  phase on the (anti)- e fluxes. - if the  and  fluxes are equal at emission, there is no CP effect on the (anti)- e fluxes.

 e  (  =180 o )  e (  =0 o )    (  =180 o )   (  =0 o ) Numerically, we have solved the evolution with a non-zero phase : SIGNIFICANT CP EFFECTS in the supernova.

Effects in an observatory due to a galactic explosion at 10 kpc (ex. water Cherenkov like Super-Kamiokande, 22.5 ktons) CP EFFECTS at the level of 5 % in an observatory. A.B. Balantekin, J. Gava, C. Volpe, arXiv:

e + p n + e+ e atmospheric background relic e flux hierarchy  13 e reactor background RELIC SUPERNOVA Relic neutrino fluxes bring information about the explosion, the supernova formation rate and neutrino properties. C. Volpe, J. Welzel, arXiv: We have performed a detailed analysis of the three technologies considered for future observatories and proposed to measure both electron neutrinos and anti-neutrinos. INFORMATION ON THE MASS HIERARCHY AND THE VALUE OF THE THIRD MIXING ANGLE. MEMPHYS EVENTS MeV 142 – 248 e MeV e

Conclusions et Perspectives Neutrino astronomy brings crucial information on the properties of particles and fundamental interactions. Next generation neutrino detectors can observe a future (extra)galactic explosion and relic supernova neutrinos (Design Study, LAGUNA, just financed within FP7). CP VIOLATION Significant effects found in the supernova under certain conditions. More work to be done. In particular, we need to include the neutrino-neutrino interaction. Recent studies have shown that the inclusion of this interaction seriously modifies the propagation in the star (the Mikheyev-Smirnov-Wolfenstein studied since the eighties).

Thank you for your attention! « NNN08 » September 11th-13th, 2008 at APC, Paris

Guglielmi et al

CERN-to-FREJUS -BEAMS 130 km MEMPHYS 400 kTon Water Cerenkov Detector CERN Geneve FREJUS Frejus Underground Laboratory Neutrino experiments : Study of CP and T violation, by comparing the following oscillation probabilities : CP T (with Beta-beams) (with conventional beams) e   (  +)    e (  + ) e   (  -)    e (  - ) …a rich physics program! Astrophysics studies Supernova neutrinos Proton decay Besides : De Bellefon et al., hep-ex/

Sensitivity to theta 13 Mezzetto, Nucl. Phys. 143, (2005). CC events Oscillated 529 Beam back. 0 Detector back. 397  = Ne  = 60 ( 6 He) 100 ( 18 Ne)

Comparison of the beta-beam sensitivity with other “third generation” projects ISS study, to appear. M. Mezzetto, NUFACT05 ONE CAN EXPLORE  13 values as small as 1 degree and  VALUES AS LOW AS 20 degrees.