Kopylov A.V. Erice School/Workshop 2009 on Neutrinos in Cosmology, in Astro, in Particle and in Nuclear Physics in Erice/Trapani/Sicily/Italy on September 16 – 24 in Centro Ettore Majorana in Erice Prospects to observe a CNO cycle by solar neutrinos. Institute for Nuclear Research of Russian Academy of Sciences Moscow, Russia (Work done in collaboration with V. Petukhov) A.Kopylov and V.Petukhov JCAP10(2008)007; JCAP08(2009)006 Supported by Russian Fund of Basic Research Scientific motivation to detect neutrinos from CNO cycle Neutrino fluxes in case of mixing. The prospects for future CNO experiments.

Hans Bethe “Energy production in stars” Phys.Rev. 55 (1939) 434

“Űber Elementumwandlungen in Innern der Sterne” Physikalische Zeitschrift 39 (1938) 633 Carl von Weizsäcker

Kopylov A.V. Erice School/Workshop 2009 on Neutrinos in Cosmology, in Astro, in Particle and in Nuclear Physics in Erice/Trapani/Sicily/Italy on September 16 – 24 in Centro Ettore Majorana in Erice Carbon-Nitrogen cycle: ~1% of energy generation In the Sun Main source of energy at higher masses Flux F 13 Flux F 15 CNO cycle is closed at stellar temperatures: Couture A. ” 19 F(p,g) 20 Ne and the Stellar CNO burning cycle” 2005 PhD Dissertation Notre Dame, Indiana

Kopylov A.V. Erice School/Workshop 2009 on Neutrinos in Cosmology, in Astro, in Particle and in Nuclear Physics in Erice/Trapani/Sicily/Italy on September 16 – 24 in Centro Ettore Majorana in Erice J.N.Bahcall, A.M.Serenelli and S.Basu (2005) Astrophys. J. 621, L85

Neutrinos from CNO Cycle Kopylov A.V. Erice School/Workshop 2009 on Neutrinos in Cosmology, in Astro, in Particle and in Nuclear Physics in Erice/Trapani/Sicily/Italy on September 16 – 24 in Centro Ettore Majorana in Erice Bahcall-Pinsonneault and…

Kopylov A.V. Erice School/Workshop 2009 on Neutrinos in Cosmology, in Astro, in Particle and in Nuclear Physics in Erice/Trapani/Sicily/Italy on September 16 – 24 in Centro Ettore Majorana in Erice -10% -20% -40% Bahcall J.N., Serenelli A.M. and Basu S, (2005) Astrophys.J. 621, L85

Kopylov A.V. Erice School/Workshop 2009 on Neutrinos in Cosmology, in Astro, in Particle and in Nuclear Physics in Erice/Trapani/Sicily/Italy on September 16 – 24 in Centro Ettore Majorana in Erice E n e r g y b a l a n c e 0.918f pp f pep f f CNO = f pp f pep = f f CNO CNO neutrinos are the last missing chain in the energy balance of the Sun The observed luminosity – what was generated years ago, the neutrino fluxes – what is generated now, i.e. to compare present with the past. Z.Fazel, J.P.Rozelot, S.Lefebre, A.Ajabshirizadeh and S.Pireaux, arXiv: v1 [astro-ph.SR]

Kopylov A.V. Erice School/Workshop 2009 on Neutrinos in Cosmology, in Astro, in Particle and in Nuclear Physics in Erice/Trapani/Sicily/Italy on September 16 – 24 in Centro Ettore Majorana in Erice E n e r g y b a l a n c e 0.918f pp f pep f f CNO = f pp f pep = f f CNO CNO neutrinos are the last missing chain in the energy balance of the Sun Uncertainty in Borexino: 10% - now, 5% - in future To have the same contribution to the uncertainty in the evaluation of the total flux of pp-neutrinos one should measure the CNO flux with the uncertainty of about 35%  the uncertainty of a lithium experiment about 10%  4 runs 90 days each with 10 tons of lithium and 30% efficiency of counting of 7 Be Borexino hep-ph f pp f CNO f pp = The statement f pp = 1.00 ± 0.01 is not true, although one can find it in a number of reports!

Kopylov A.V. Erice School/Workshop 2009 on Neutrinos in Cosmology, in Astro, in Particle and in Nuclear Physics in Erice/Trapani/Sicily/Italy on September 16 – 24 in Centro Ettore Majorana in Erice E n e r g y b a l a n c e 0.918f pp f pep f f CNO = f pp f pep = f f CNO CNO neutrinos are the last missing chain in the energy balance of the Sun Uncertainty in Borexino: 10% - now, 5% - in future Precise measurements of the fluxes of F7 and F13+F15 enable to find the total flux of neutrinos, generated in the Sun – analogous to a neutral current measurements in SNO experiment (if there’s no transition to sterile neutrinos). To discover sterile neutrinos one should measure precisely the flux of electron pp- neutrinos as well. Borexino hep-ph f pp f CNO f pp = The statement f pp = 1.00 ± 0.01 is not true, although one can find it in a number of reports!

What are the fluxes F13 and F15 if the core of the Sun gets mixed with peripheral layers? To be compatible with the results of helioseismology  to stay within the fixed surface abundances: (a) 4 He:  = 1.8%(b) 1 H:  = 0.6%(c) 12 C:  = 12%(d) 12 N:  = 15% and with mean molecular weight   = 4/(6X+Y+2)  = 0.5% in the solar core r < 0.2R Sun Kopylov A.V. Erice School/Workshop 2009 on Neutrinos in Cosmology, in Astro, in Particle and in Nuclear Physics in Erice/Trapani/Sicily/Italy on September 16 – 24 in Centro Ettore Majorana in Erice

The set of equations for a CNO cycle: Only temporal evolution, coordinates are omitted !

Kopylov A.V. Erice School/Workshop 2009 on Neutrinos in Cosmology, in Astro, in Particle and in Nuclear Physics in Erice/Trapani/Sicily/Italy on September 16 – 24 in Centro Ettore Majorana in Erice and the one for pp chain:  ij =  N A Two sets are solved independently, very small link between these two sets…

Kopylov A.V. Erice School/Workshop 2009 on Neutrinos in Cosmology, in Astro, in Particle and in Nuclear Physics in Erice/Trapani/Sicily/Italy on September 16 – 24 in Centro Ettore Majorana in Erice D u r a t I o n o f m I x I n g  versus the abundance of 4 He on the surface Mean molecular weight is more limiting than Y surf

Kopylov A.V. Erice School/Workshop 2009 on Neutrinos in Cosmology, in Astro, in Particle and in Nuclear Physics in Erice/Trapani/Sicily/Italy on September 16 – 24 in Centro Ettore Majorana in Erice  versus the abundance of 14 N on the surface D u r a t I o n o f m I x I n g and more limiting than the abundance of 14 N on the surface

Kopylov A.V. Erice School/Workshop 2009 on Neutrinos in Cosmology, in Astro, in Particle and in Nuclear Physics in Erice/Trapani/Sicily/Italy on September 16 – 24 in Centro Ettore Majorana in Erice D u r a t I o n o f m I x I n g  versus the neutrino flux F 13 Big changes of F 13

Kopylov A.V. Erice School/Workshop 2009 on Neutrinos in Cosmology, in Astro, in Particle and in Nuclear Physics in Erice/Trapani/Sicily/Italy on September 16 – 24 in Centro Ettore Majorana in Erice D u r a t I o n o f m I x I n g  versus the neutrino flux F 15 and no noticeable change of F 15

Kopylov A.V. Erice School/Workshop 2009 on Neutrinos in Cosmology, in Astro, in Particle and in Nuclear Physics in Erice/Trapani/Sicily/Italy on September 16 – 24 in Centro Ettore Majorana in Erice D u r a t I o n o f m I x I n g  versus the neutrino flux F 7 The change of F 7 is well below the accuracy of Borexino

e - - scattering Kopylov A.V. Erice School/Workshop 2009 on Neutrinos in Cosmology, in Astro, in Particle and in Nuclear Physics in Erice/Trapani/Sicily/Italy on September 16 – 24 in Centro Ettore Majorana in Erice To have the data from independent experiments - the key issue.

Kopylov A.V. Erice School/Workshop 2009 on Neutrinos in Cosmology, in Astro, in Particle and in Nuclear Physics in Erice/Trapani/Sicily/Italy on September 16 – 24 in Centro Ettore Majorana in Erice

7 Li + e > 7 Be + e - Both initial and final states are mirror nuclei. The transition is super-allowed. The cross- section is high and can be calculated with very good accuracy, better than 1%. The abundance of 7 Li in natural lithium is high (93%), the mass of the target is small (~10 tons). The threshold is 0.86 MeV, I.e. very high sensitivity to neutrinos of medium energy ( 7 Be, pep, CNO) V.A.Kuzmin and G.Zatsepin On the neutrino spectroscopy of the Sun, in Proceedings of 9 th International Cosmic Ray Conference, London, 1965, p.1024 J.N.Bahcall Phys.Lett. 13 (1964) 332 J.N.Bahcall Phys.Rev.Lett. 23 (1969) 251 Fig.1 from : A. Kopylov and V. Petukhov, Physics Letters, B 544(2002)11-15

Kopylov A.V. Erice School/Workshop 2009 on Neutrinos in Cosmology, in Astro, in Particle and in Nuclear Physics in Erice/Trapani/Sicily/Italy on September 16 – 24 in Centro Ettore Majorana in Erice I –Low Z and no mixing, II – Low Z, III – Low Z with mixing, IV – High Z, V – High Z with mixing. I and V are in a strong (3s) contradiction, i.e. the most informative regions, (III&IV) – marginal. 20 SNU – 1.5 cpd In 10 tons of Li. If the efficiency of Counting ~30%, then ~10% stat. acc. For 1 year of expos. ~4% for 10 years The uncertainties for 10 tons of lithium 10 years of experiment f 13 Z Integral measurements

Kopylov A.V. Erice School/Workshop 2009 on Neutrinos in Cosmology, in Astro, in Particle and in Nuclear Physics in Erice/Trapani/Sicily/Italy on September 16 – 24 in Centro Ettore Majorana in Erice CONCLUSIONS Neutrinos from CNO cycle are the last missing chain in the energy balance of the Sun. This is the main motivation to study the CNO neutrinos in future experiments. The measurement of the fluxes of CNO neutrinos is vital for the resolution of HIGH Z – LOW Z problem. The internal core mixing has a signature which can be identified in future measurements as the increased flux F 13. Newly developed electronic detectors measuring the differential spectrum are approaching the sensitivity adequate to “see” the CNO neutrinos. A radiochemical lithium detector as an integral detector of solar neutrinos has good prospects for independent measurements. At present the R&D efforts are concentrated to reach the level of about 30% for the efficiency of counting of 7 Be.

Kopylov A.V. Erice School/Workshop 2009 on Neutrinos in Cosmology, in Astro, in Particle and in Nuclear Physics in Erice/Trapani/Sicily/Italy on September 16 – 24 in Centro Ettore Majorana in Erice ACKNOWLEDGEMENTS The work on a lithium project was partially supported by Russian Fund of Basic Research (RFBR) : grants , A Deep appreciation to RFBR for the support of my attendance to Erice School/Workshop Many thanks to organizing committee for invitation to come to Erice and for all efforts

Thank you