1. October 3, 2003IFIC, UVEG-CSIC A road map to solar fluxes, osc. param., and test for new physics Carlos Pena Garay IAS ~

2. Why perform low-energy solar neutrino experiments? Update : SNO 2 nd phase data included

3. Strategy - Global analyses of data : Indep. on SSM fluxes Bahcall, Krastev, PRD53 (1996) Garzelli, Giunti, PRD65 (2002) 1995 : Chlorine, SAGE, GALLEX, Kamiokande Large uncertainties of fluxes from neutrino data 2001 : Chlorine, SAGE, GALLEX, SK, SNO CC Bayesian Analysis : 5% p-p determination at 90% CL 2001 : pp SSM analysis of pp measurement Nakahata, NOON 2001

4. Neutrino spectrum

5. S + K Solar + KamLAND : Data 1 Chorine 0.34 0.03 1 Sage + Gallex/GNO 0.54 0.03 44 Super-Kamiokande 0.465 0.015 SNO I CC* 0.35 0.02 34 SNO I NC* 1.01 0.13 SNO I ES* 0.47 0.05 KamLAND 0.61 0.09 * undistorted spectrum assumed 1 SNO II CC 0.32 0.02 1 SNO II NC 1.03 0.09 1 SNO II ES 0.44 0.06

6. S + K : Global analyses Global analyses : Variations on a theme - B free - B, Be free - All free - All free + lum - - Cl, - Ga

7. LMA : Boron free analysis

8. LMA

9. CHOOZ + ATM :

10. If nuclear fusion reactions among light elements are responsible for solar energy generation Spiro, Vignaud, PLB (1990) determined by differences of nuclear masses independent of details of solar model at 1:10 4 Bahcall, PRC (2002) Luminosity constraint

11. Global : Variations on a theme - S + K : All free + lum Amazing result ! Large uncertainty ! Luminosity constraint is relevant ! - S+ K : All free

12. LMA : Other analyses - S + K : All free + lum – Ga Data don’t understand Be neutrinos ! - S + K : All free + lum – Cl Do we really understand Be neutrinos?

13. LMA : Other determinations - S + K : All free - luminosity from neutrino data Bahcall, Gonzalez-Garcia, CPG, PRL (2003) - S + K : All free + lum

14. LMA : Predictions for Borexino - S + K : All free + lum Do we really understand Be neutrinos? - S + K : B free

15. S + K 3 yr

16. Expected at Borexino [Be] = 0.66 10% [Be] = 0.66 5%

17. Unexpected at low energy ? -NC NSI : Modified matter effects Fogli et al (2002) Berezhiani et al (2001) Davidson et al (2003) -Sterile : With low mass scale Berezinsky et al (2003) de Holanda, Smirnov (2003)

18. Expected : pp measurement [pp]= 0.70 5% [pp]= 0.70 1%

19. Summary

20. 7 Experiments; 34 years; 0.01% of the flux. A solar neutrino “opportunity”; not a problem.

21. Free fluxes: with luminosity constraint

22. Why measure low-energy solar `s? (today) Unique test of stellar fusion reactions Test for vacuum-matter transition Measure solar luminosity via `s Explore for new physics (steriles, NSI)

27. Conclusions Next I SNO 2 nd phase - Status of maximal mixing - Matter effects Next I KamLAND reactor : determination Next II Low energy : challenge - 99.99 % of solar neutrinos E < 5 MeV - Redundancy + improvement : Identify the unexpected - Vacuum av. osc. - Luminosity constraint + [ Be] 5% + [p-p] 1-3% 7

28. :Significant improvement But… SSM dependent + p-p (pep) measurement : SSM Nakahata, NOON 2001

29. S + K 3 yr : S + K 3 yr + [Be] 5 % Larger unc. than SSM Smaller unc. than SSM !!! Higher sensitivity to pp/pep: Luminosity constraint

30. : Significant improvement and… SSM independent at < 0.01 % + p-p (pep) measurement

31. 7 Be measurement at 5 % Not improved But !

32. Better sensibility Small CS uncertainty [X] ~ P CC ee [X] ~ P + f (1-P ) ee ee Low Energy exps : ES, CC