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 andcosmology

Solar, SNII, UHE, BBN, LSS, leptogenesis, …

Particle physics Standard Model andbeyond

AN EXCITINGINTERDISCIPLINARYDOMAIN !

THE first OBSERVATION of SOLAR e

From fusion reactions, like p+p 2H+e++e

1970 the detector

Homestake mine (South Dakota)600 tons of C2Cl4

e + 37Cl 37Ar + e-

« We observe much lessneutrinos 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

3

2

1

1212

1212

1313

1313

2323

2323

100

0

0

0

010

0

0

0

001

cs

sc

ces

esc

cs

sci

ie 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.ijijc cos ijijs sin

23 1312

THE OSCILLATION PARAMETERS

PLANII. Supernova neutrinos andneutrino properties

Conclusions and Pespectives

I. Core-collapse supernova neutrinos :A brief overview

Totani et al., Astr.. J. 1998

t (s)0.1 1. 10

I.Core-collapse SUPERNOVAE

collapsee burst cooling

NEUTRINOS FOLLOW CLOSELYTHE 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

SN1987A

EVENTS

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 9000MEMPHYS 140000

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 propagationin the starluminosities, spectra,time distribution of theemitted neutrinosnucleosynthesis (r-process)

…

Earth detection

PROPAGATION IN THE STARThe Mykheyev-Smirnov-Wolfenstein (MSW effect, ’78 and ’86) :

V() GF e.

e

e e

e

W

m2

vacuum high

1

coeurcore

1

fluxes at emissione

10

A = -m2/4E cos2 B = -m2/4E sin2

A potential is introduced due to the coupling with matter.

ee

AB

BVA

dt

di

)(

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 :sin2213< 0.1

Two neutron events depend on theelectron neutrino temperature, andtherefore 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 ofintense and pure low energy neutrino beams (10-100 MeV).

boost

6He 6He

close detector

PS

SPS

EURISOL

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 2004Jachowicz and McLaughlin PRL 2006Jachowicz et al in preparation 2007

….

fundamental interaction studies (Weinberg angle, CVC test, , etc…):McLaughlin and Volpe, PLB 2004, Balantekin et al PLB 2006Balantekin et al PRD 2006Bueno et al PRC 2006Barranco et al 2006Amanik et al PRD 2007

….

neutrino-nucleus interaction Volpe J Phys G 2004Serreau and Volpe PRC 2004McLaughlin PRC 2004Lazauskas and Volpe NPA 2007

….

Off-axis options : Lazauskas et al PRD 2007, Amanik et al PRC 2007 .

C.Volpe, Review on “Beta-beams”, J. Phys. G34, R1 (2007), hep-ph/0605033

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:0710.3112

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.

SHSH )0(~)(~ SUSU )0(~)(~

)()()()( eeeeev vvPLvvvPLvvvPLve

)0,(),( eeee vvPvvP

)0,()0,(),(),( eeee vvPvvPvvPvvP

e(=180o)e(=0o)

(=180o)(=0o)

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:0710.3112

e + p n + e+

e atmosphericbackground

relic e flux

hierarchy13

e reactorbackground

RELIC SUPERNOVA Relic neutrino fluxes bring information about the explosion, the supernova formation rate and neutrino properties.

C. Volpe, J. Welzel, arXiv:0711.3237

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.

MEMPHYSEVENTS 19.3 - 27 MeV 142 – 248 e

12 - 50 MeV 12 - 19 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 toinclude 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, Parishttp://nnn08.in2p3.fr/

Guglielmi et al. 2005.

CERN-to-FREJUS -BEAMS

130 km

MEMPHYS400 kTonWaterCerenkovDetector

CERN

Gen

eve

FREJUS

Frejus Underground Laboratory

Neutrino experiments : Study of CP and T violation,by comparing the followingoscillation 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/0607026

Sensitivity to theta13

Mezzetto, Nucl. Phys. 143, (2005).

CC events 144784Oscillated 529Beam back. 0Detector back. 397

= 100 18Ne

= 60 (6He) 100 (18Ne)

Comparison of the beta-beam sensitivitywith 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.