A. Y. Smirnov

SNO: establishing flavor conversion of the Solar neutrinos BOREXINO direct measurement of the pp-neutrinos 2004 – KAMLAND identified the LMA MSW solution of the solar neutrino problem 2015 – back to the Sun?

Neutrinos from the primary pp-reactions in the Sun BOREXINO Collaboration (G. Bellini et al.) Nature 512 (2014) 7515, 383 Upturn? Higher accuracy cos 4  13 (1 - ½ sin 2 2  12 ) Higher accuracy on pp will contribute to global fit substantially

Super-Kamiokande collaboration (Renshaw, A. et al.) Phys.Rev.Lett. 112 (2014) arXiv: First Indication of Terrestrial Matter Effects on Solar Neutrino Oscillation KL solar Large fluctuations of data Core is not seen - attenuation positive Below average

Oscillations in matter of the Earth 4p + 2e -  4 He + 2 e MeV Adiabatic conversion BOREXINO LMA MSW Loss of coherence Mass states split and oscillate

M. Maltoni, AYS. Review Solar neutrinos and Neutrino physics EJP, to appear A.Ioannisian, AYS, D. Wyler [hep-ph] PRD

Vacuum dominated Transition region resonance turn on M. Maltoni, A.Y.S. to appear Matter dominated region best fit value from solar data best global fit upturn for two different values of  m 21 2 Reconstructed exp. points for SK, SNO and BOREXINO at high energies

Best global Solar only SNO SK SNO+

M. Maltoni, A.Y.S. to appear Solar neutrinos Vs. KamLAND Red regions: all solar neutrino data also restrictions from individual experiments sin 2  13 fixed by reactor experiments KamLAND data reanalized in view of reactor anomaly (no front detector) bump at 4 -6 MeV  m 2 21 increases by eV 2  m 2 21 : about 2  descrepancy of the KL and solar values

allowed regions sin 2  13 and sin 2  12 b.f.: sin 2  13 = b.f.: sin 2  13 = Solar + KamLAND Solar only

S. Goswami, A. Yu. S. : hep-ph/ sin 2  13 = / Measuring 1-2 and 1-3 mixings New SNO Phys.Rev. D72 (2005) Effect is not just overall normalization of the flux

V = a MSW V stand Determination of the matter potential from the solar plus KamLAND data using a MSW as free parameter a MSW G. L Fogli et al hep-ph/ C. Pena-Garay, H. Minakata, hep-ph [hep-ph] the best fit value a MSW = 1.66 a MSW = 1.0 is disfavoured by > 2  a MSW = 0 is disfavoured by > 15  M. Maltoni, A.Y.S. to appear related to discrepancy of  m 2 21 from solar and KamLAND:  m 2 21 (KL)  m 2 21 (Sun) = 1.6 V  m 2 21 Potential enters the probability in combination

Inside the Sun highly adiabatic conversion  The averaged survival probability is scale invariant = no dependence on distance, scales of the density profile, etc.  E =  m 21 2 L /2E P ee = P ee (  12,  13,  E ) 2VE  m 21 2  12 = Function of the combinations Very weak dependence  13 = 2VE  m 31 2 With oscillations in the Earth L – the length of the trajectory in the Earth If oscillations in the Earth are averaged P ee = P ee (  12,  13 ) = P ee (  12 )  m ij 2  a  m ij 2, V  a V Invariance:  m ij 2  b  m ij 2, E  b E a = -1 flip of the mass hierarchy

Solar neutrino data only no Earth matter effects Adiabaticity violation in the Sun l > R SUN Non-averaged oscillations in the Earth  m 2 21 = a MSW  m 2 21 V = a MSW V stand app. 4 

Absence of upturn of the spectrum Large D-N asymmetry Difference of values of  m 2 21 extracted from solar and KamLAND data Large value of matter potential extracted from global fit Can be related Solar data alone have very good and consistent description at small  m 2 21 New sub-leading effects Reactor anomaly should affect KamLAND result Non-standard Neutrino interaction Very light Sterile neutrinos at about 3  - level another reactor anomaly? in solar neutrinos?

M C. Gonzalez-Garcia, M. Maltoni arXiv  f D  f N  f N  f D V NSI = 2 G F n f Allowed regions of parameters of NSI Additional contribution to the matrix of potentials in the Hamiltonian In the best fit points the D-N asymmetry is 4 - 5% f = e, u, d

Extra sterile neutrino with  m 2 01 = 1.2 x eV 2, and sin 2 2  = Non-standard interactions with  u D = ,  u N =  d D = ,  d N = M. Maltoni, A.Y.S. to appear difference

  e mass  m 2 31  m  m 2 01 s additional radiation in the Universe if mixed in 3 sterile neutrino no problem with LSS bound on neutrino mass m 0 ~ eV sin 2 2  ~ sin 2 2  ~ (IH) sin 2 2  ~ (NH) For solar nu: For dark radiation sin 2  sin 2  Adiabatic conversion for small mixing angle Adiabaticity violation Allows to explain absence of upturn and reconcile solar and KAMLAND mass splitting but not large DN asymmetry

Absence of upturn of the spectrum Large D-N asymmetry Difference of values of  m 2 21 extracted from solar and KamLAND data Large value of matter potential extracted from global fit Detection of CNO neutrinos to shed some light on the problem of the SSM: controversy of helioseismology data and abundance of heavy elements High precision measurements of the pp- pep- and Be- neutrino fluxes Detailed study of the Earth matter effect Clarification of Searches for new physics effects

870 tons Double beta decay of Te Simultaneously solar with E > 3 MeV, upturn later pep- CNO- later LS 20 kt, too shallow, background? Not much to add? e events/ year Lower PMT coverage, E > 7 MeV Shallower than SK 20 times larger background, (4 – 5)  D-N in 10 years

 Be /E =  Be = 1.6 kev E = kev A.N. Ioannisian, A.Y.S., D. Wyler BOREXINO: A DN = / (stat) +/ (syst)  Be ~  E T Oscillatory period in the energy scale  E T = E l /L = E l 2 R E cos  Depending on nadir angle  level of averaging changes For different trajectories.  = 1.4 (red); 1.0 (blue); 0.7 (blue) Be7 line probability coincidence

2VE  m 21 2  = = (  /2.7g cm -3 ) Oscillations of mass eigenstates – pure matter effect l m = l [ 1 + c 13 2 cos 2  12  + …] = 28.5 km A e = (P – P D )/P D = - c 13 2 f(  m 21 2,  12  13 ) ½ dx V(x) sin  m x  L Variations f = 0.43 Constant density A e = - c 13 2  f sin 2 ½  m L  m = 2  / l m L 0

Nadir angle

The relative change of the electron neutrino flux for the mantle crossing trajectories as the function of for two different values of width of the 7Be line which correspond to two different temperatures in the center of the Sun: T = degrees (solid line); T = degree (dashed line). Nadir angle

Effect of averaging over the production region of 7Be neutrinos in the Sun. The relative change of the electron neutrino flux for mantle crossing trajectories with = without (dotted line) and with (dash-dotted line) averaging. For deeper trajectories the effect of averaging is smaller.

In the configuration space: separation of the wave packets due to difference of group velocities 2 x  v gr =  m 2 /2E 2 1 no overlap:  leads to the same coherence length xx separation:  x sep S =  v gr L =  m 2 L/2E 2  v gr L >  x coherence length: L coh =  x E 2 /  m 2 In the energy space: averaging over oscillations E T = 4  E 2 /(  m 2 L) Averaging (loss of coherence) if energy resolution  E is E T <  E If E T >  E - restoration of coherence even if the wave packets separated Oscillatory period in the energy space

m2E3m2E3 x  spread =  E L Due to presence of waves with different energies in the packet Dispersion of the velocities with energy

 spread =  E L SUN = cm  x = 2  /  Be = cm m2E3m2E3 spread: On the way from the Sun to the Earth:  x sep S =  v gr L SUN =  m 2 L SUN /2E 2 = cm separation of WP for hierarchical spectrum  x sep E =  m 2 L/2E 2 = cm separation of WP in the Earth L E 10 4 km No separation – no coherence loss, no averaging ?  x sep E <<  spread  x sep S >>  spread In the energy space – no spread of the WP: coherence condition is not affected by the spread

WP becomes “classical”: describing that the highest energy neutrinos arrive first Loss of coherence between different parts of the WP m2E3m2E3 x No effect on coherence if considered in the p-space  spread =  E L J. Kersten, AYS Although the shift is small the overlapping parts of the WP will lose coherence

Establishing oscillations, matter effect Quasi- periodic variations during night Determination of the line width Precision measurements of  m 21 2 Tomography of the Earth interior - Small scale structures, at the surface (mountains, oceans,..) - Non-sphericity of the Earth - Density jumps in the mantle, - Shape of the core,,, Searches for sterile neutrinos especially for  m 10 2 ~  eV 2 sin 2 2  s ~ 10 -2

Next generation of large (several tenth of ktons to a hundred ktons) scintillator detectors like JUNO will have sub-percent sensitivity to the Day-Night asymmetry. Water based liquid scintillator, J. R. Alonso, N. Barros, M. Bergevin, A. Bernstein, L. Bignell, E. Blucher, F. Calaprice and J. M. Conrad. et al., arXiv: [physics.ins-det]. Higher sensitivity can be achieved with 100 kton mass scale scintillator uploaded water detectors, WBLS.. For 100 kton fiducial mass and 5 years exposure such a detector will collect bigger statistics than in BOREXINO Correspondingly, the statistical error will be reduced down to If systematic errors is well controlled, the 0.1% size Earth matter effects on the 7Be neutrinos can be established at about 3 level.

Solar neutrino physics is not over Certain tension between data exists which must be understood/resolved Still it can be statistical fluctuation or some overlooked systematics or some new physics is behind Solar neutrinos - strong potential to search for new physics: new neutrino states, new interactions, new dynamics, violation of fundamental symmetries Experimental program is not very sound/ dedicated usually some addition/lateral to other issues: mass hierarchy, CP violation, supernova neutrinos New level of accuracy, new effects become accessible, new opportunities to search for physics beyond 3 - paradigm and BSM

Jiangmen Underground Neutrino Observatory d = 700 m, L = 53 km, P = 36 GW 20 kt LAB scintillator n + p  d +  Also RENO-50 Key requirement: energy resolution 3% at 1 MeV

Before direct pp- measurements cos 4  13 (1 - ½ sin 2 2  12 ) Neutrinos from the primary pp-reactions in the Sun BOREXINO Collaboration (G. Bellini et al.) Nature 512 (2014) 7515, 383 Upturn? Higher accuracy

Super-Kamiokande collaboration (Renshaw, A. et al.) Phys.Rev.Lett. 112 (2014) arXiv: First Indication of Terrestrial Matter Effects on Solar Neutrino Oscillation fluctuations?

1σ, 90 %, 2σ, 99% and 3σ CL (for 2 dof) allowed regions. Full - GS98 model, bf - blackstar; Dashed - AGSS09 model (bf - white dot), Green - KamLAND ; Orange - GS98 model, without the D-N from SK. Δχ2 dependence on  m 21 2 for the same four analysis after marginalizing over  12. fixed θ 13 = 8.5 ∘ Solar data vs KamLAND About 2  discrepancy A. Suzuki: CPT violation? K. Fujikawa, A. Tureanu, [hep-ph] Non-local interactions in Nu portal  CPT violation  nu-antinu mass splitting Very light sterile neutrino? P de Holanda, AYS

core mantle flavor-to-flavor transitions Oscillations in multilayer medium  - nadir angle core-crossing trajectory  -zenith angle  = 33 o  - accelerator - atmospheric - cosmic neutrinos Applications: mass-to-flavor transitions - solar neutrinos - supernova neutrinos

 i = - E i t + p i x group velocity  =  E/v g (v g t - x) + x  m 2 2E  =  Et -  px  p = (dp/dE)  E + (dp/dm 2 )  m 2 = 1/v g  E + (1/2p)  m 2 p i = E i 2 – m i 2  x  E ~  m 2 /2E  x  m 2 /2E usually- small  =  2  -  1 standard oscillation phase Dispersion relation where insert These are averaged characteristics of WP Oscillation effect over the size of WP

Vacuum dominated Transition region resonance turn on M. Maltoni, A.Y.S. to appear Matter dominated region best fit value from solar data best global fit upturn for two different values of  m 21 2 Reconstructed exp. points for SK, SNO and BOREXINO at high energies Energy dependent deficit of signal sin 2  12 1 – ½ sin 2 2  12