1 The pp-chain and the CNO-cycle after KamLAND Solar neutrinos after SNO and KamLAND The Boron flux The Beryllium flux Nuclear physics of the pp-chain Can the sun shine with CNO? New challenges for solar model builders The Sun as a laboratory for fundamental physics Main message: accurate determinations of S 17,S 34 and S 1,14 are particularly important now. GF and BR LNGS

2 SNO: the appearance experiment A 1000 tons heavy water detector sensitive to B-neutrinos by means of: CC: e +d -> p + p + e CC: e +d -> p + p + e sensitive to e only, provides a good measurement of e spectrum with weak directionality NC: x +d -> p + n + x NC: x +d -> p + n + x all Equal cross section for all flavors. It measures the total 8 B flux from Sun. ES: x +e -> e + x ES: x +e -> e + x Mainly sensitive to e, strong directionality. The important point is that SNO can determine both: and  ( e ) and  ( e +  +  )

3 SNO results The measured total B neutrino flux is in excellent agreement with the SSM prediction: About 2/3 of produced e transform into  and/or . LMAThe large mixing angle (LMA) solution is preferred by a global fit of Chlorine, Gallium, SuperK and SNO data. LMA LOW JUST-SO (1 

4 The first KamLAND results Source: anti- e from distant (  100 km) nuclear reactors Detector: 1Kton liquid scintillator where: Anti  e +p -> n + e + n + p -> d +  Measure the energy released in the slowing down and annihilation of e + E vis =T+2m e in the presence of the 2MeV  ray. Observed/Expected= 54/ ( ) - >Oscillation of reactor anti- e proven - > Oscillation of reactor anti- e proven Best fit  m 2 = eV 2 ; sin 2 2  = >LMA solution for solar neutrinos confirmed. - > LMA solution for solar neutrinos confirmed.

5 The impact of KamLAND first results on solar neutrinos After KamLAND  m 2 is restricted to the region (5-20)10 -5 eV 2. Before After LMA Bahcall et al. hep-ph/ , Fogli et al. hep-ph/ …. LMA LOW Just-So

6 Bruno Pontecorvo The Cl-Ar method Neutrino sources (sun, reactors, accelerators) Neutrino oscillations Neutron Well LoggingA New Geological Method Based on Nuclear Physics Neutron Well Logging - A New Geological Method Based on Nuclear Physics, Oil and Gas Journal, 1941, vol.40, p the neutron logAn application of Rome celebrated study on slow neutrons, the neutron log is an instrument sensitive to water and hydrocarbons. It contains a (MeV) neutron source and a (thermal) neutron detector. As hydrogen atoms are by far the most effective in the slowing down of neutrons, the distribution of the neutrons at the time of detection is primarily determined by the hydrogen concentration, i.e. water and hydrocarbons.

7 From neutrons to neutrinos We have learnt a lot on neutrinos. Their survival/transmutation probabilities in matter are now understood. We have still a lot to learn for a precise description of the mass matrix (and other neutrino properties…) Now that we know the fate of neutrinos, we can learn a lot from neutrinos.

8 What next? Neutrinos and Supernovae Neutrino contribution to DM Neutrinos and the Earth Neutrinos and the Sun

9 The measured boron flux The total active    ( e +  +   boron flux is now a measured quantity. By combining all observational data one has*:   = 5.05 (1 ± 0.06) 10 6 cm -2 s -1. The central value is in perfect agreement with the Bahcall 2000 SSM present   /   =6%Note the present 1  error is   /   =6% next few years   /    3%In the next few years one can expect to reach   /    3% * Bahcall et al. hep-ph BP2000FRANECGARSOM   [10 6 s -1 cm -2 ]

10 s 33 s 34 s 17 s e7 s pp Nuclear The Boron Flux, Nuclear Physics and Astrophysics   depends on nuclear physics and astrophysics inputs Scaling laws have been found numerically* and are physically understood   =   (SSM) · s s s 17 1 s e7 -1 s pp -2.7 · com 1.4 opa 2.6 dif 0.34 lum 7.2 These give flux variation with respect to the SSM calculation when the input X is changed by x = X/X (SSM). Can learn astrophysics if nuclear physics is known well enough.  astro * Scaling laws derived from FRANEC models including diffusion. Coefficients closer to those of Bahcall are obtained if diffusion is neglected.

11 Uncertainties budget Nuclear physics uncertainties, particularly on S 17 and S 34, dominate over the present observational accuracy   /   =6%. The foreseeable accuracy   /   =3% could illuminate about solar physics if a significant improvement on S 17 and S 34 is obtained. For fully exploiting the physics potential of a   measurement with 3% accuracy one has to determine S 17 and S 34 at the level of 3% or better. Source  S/S(1   /   S330.06*0.03 S S17** Se70.02 Spp Com Opa Dif0.10***0.03 Lum *LUNA gift **Adelberger estimate: see below ***by helioseismic const. [gf et al.A&A 342 (1999) 492] See similar table in JNB, astro- ph/

12 Progress on S 17 S 17 (0) [eV b] Ref. Adel.-Review RMP 70,1265 (1998) Nacre-Review 21 ± 2 NP 656A, 3 (1999) Hammache et al 18.8 ± 1.7 PRL 86, 3985 (2001) Strieder et al 18.4 ± 1.6 NPA 696, 219 (2001) Hass et al 20.3 ± 1.2 PLB 462, 237 (1999). Junghans et al.* 22.3 ± 0.7 PRL 88, (2002) Baby et al ± 0.7 PRL. 90, (2003) *” The cross section values of this paper are currently being revised” ( K.A. Snover, private communication ). Results of direct capture expts**. JNB and myself still use a conservative uncertainty (-2+4), however recently high accuracy determinations of S 17 have appeared. Average from 5 recent determinations yields: S 17 (0)= 21.1 ± 0.4 with    dof=2 IfIf one omits Junghans et al.* one finds: S 17 (0)= 20.5 ± 0.5 with    dof=1.2 If we add in quadrature an “error in theory” of ± 0.5 we get a consistent common value: S 17 (0)= 20.5 ± 0.7 eV b S17(0)[eV b] Data published **See also Gialanella et al EPJ A7, 303 (2001)

13 1)The lowest measured energies are about 200 and 300 keV 2)Theoretical extrapolations are important so far 3)It would be most helpful to lower the energy and see if really the curve rises Comparison between most recent data Junghans et al. S17(0)=22.3 ± 0.7 eV b Baby et al. S17(0)=21.2 ± 0.7 eV b DB theory NPA 567, 341(1994)

14 Remark on S 17 and S 34 S 17 (0)= 20.5 ± 0.7 eV bIf really S 17 (0)= 20.5 ± 0.7 eV b this means a 3.5% accuracy. The 9% error of S 34 is the main source of uncertainty for extracting physics from Boron flux. LUNA results on S 34 will be extremely important. Source  S/S (1   /   S330.06*0.03 S S17** Se70.02 Spp Com Opa Dif0.10***0.03 Lum

15 The central solar temperature The various inputs to   can be grouped according to their effect on the solar temperature. All nuclear inputs (but S 11 ) only determine branches ppI/ppII/ppIII without changing solar structure. The effect of the others can be reabsorbed into a variation of the “central” solar temperature:   =   (SSM) [T /T (SSM) ] 20.. S s s 17 s e7 -1 Source dlnT/dlnS  dln  B /dlnS   S S S1701 Se70 Spp Com Opa Dif Lum (  20)Boron neutrinos are excellent solar thermometers due to their high (  20) power dependence.

16 Present and future for measuring T with B-neutrinos   /   =6%  S nuc / S nuc =At present,   /   =6% and  S nuc / S nuc = 13% (cons.) translate into  T/T= 0.7 % the main error being due to S 17 and S 34.  S nuc /S nuc =0If nuclear physics were perfect (  S nuc /S nuc =0) already now we could have:  T/T= 0.3 %   /   =3%When   /   =3% one can hope to reach (for  S nuc /S nuc =0) :  T/T= 0.15 %

17 The central solar temperature and helioseismology For the innermost part, neutrinos are now (  T/T = 0.7%) almost as accurate as helioseismology They can become more accurate than helioseismology in the future. Helioseismology determines sound speed. The accuracy on its square is  u/u 0.15% inside the sun. Accuracy of the helioseismic method degrades to 1% near the centre. Boron neutrinos provide a complementary information, as they measure T.  u/u 1  3  present  T/T future

18 The Sun as a laboratory for astrophysics and fundamental physics A measurement of the solar temperature near the center with 0.15% accuracy can be relevant for many purposes –It provides a new challenge to SSM calculations –It allows a determination of the metal content in the solar interior, which has important consequences on the history of the solar system (and on exo-solar systems) One can find constraints (surprises, or discoveries) on: –Axion emission from the Sun –The physics of extra dimensions (through Kaluza-Klein axion emission) –Dark matter (if trapped in the Sun it can change the solar temperature very near the center) – … BP-2000FRANECGAR-SOM T6T

19 Be neutrinos - In the long run (Borexino+ KamLAND+LENS…) one can expect to measure  Be with an accuracy  Be /  Be  5% -  Be is insensitive to S 17, however the uncertainty on S 34 will become important. -  Be is less sensitive to the solar structure/temperature (  Be  T 10 ). An accuracy   /    5% will provide at best  T/T  5% Source  S/S  (1    e /   e   /   S S S = Se70.02= Spp Com Opa Dif Lum Remark however that Be and B bring information on (slightly) different regions of the Sun

20 CNO neutrinos, LUNA and the solar interior The principal error source is S 1,14. The new measurement by LUNA is obviously welcome. A measurement of the CNO neutrino fluxes would provide a stringent test of the theory of stellar evolution and unique information about the solar interior. Source  S/S (1  )   /    O /  O S S S Se Spp S1, Com Opa Dif Lum Solar model predictions for CNO neutrino fluxes are not precise because the CNO fusion reactions are not as well studied as the pp reactions. Also, the Coulomb barrier is higher for the CNO reactions, implying a greater sensitivity to details of the solar model

21 Does the Sun Shine by pp or CNO Fusion Reactions? Solar neutrino experiments set an upper limit (3  ) of 7.8% (7.3% including the recent KamLAND measurements) to the fraction of energy that the Sun produces via the CNO fusion cycle, This is an order of magnitude improvement upon the previous limit. New experiments are required to detect CNO neutrinos corresponding to the 1.5% of the solar luminosity that the standard solar model predicts is generated by the CNO cycle. The important underlying questions are: Is the Sun fully powered by nuclear reactions?Is the Sun fully powered by nuclear reactions? Are there additional energy losses, beyond photons and neutrinos?Are there additional energy losses, beyond photons and neutrinos? Bahcall, Garcia & Pena-Garay Astro-ph

22 Summary Solar neutrinos are becoming an important tool for studying the solar interior and fundamental physics Better determinations of S 17, S 34 and S 1,14 are needed for fully exploiting the physics potential of solar neutrinos. All this brings towards fundamental questions: Is the Sun fully powered by nuclear reactions?Is the Sun fully powered by nuclear reactions? Is the Sun emitting something else, beyond photons and neutrinos?Is the Sun emitting something else, beyond photons and neutrinos?

23 Appendix

24 Sensitivity to the central temperature* B neutrinos are mainly determined by the central temperature almost independently of the way we use to vary T. The same holds for pp and Be neutrinos. T/T SSM  i /  i SSM B Be pp * from Castellani et al. Phys. Rep. 281, 309 (1997)

25 Sensitivity to the central temperature* * from Bahcall & Ulmer PRD 53, 4202 (1996) B  i [10 10 /cm2/s] pp  i [10 8 /cm2/s] pep T solar models without diffusion, with cross sections and element abundances varied within their uncertainties  i [10 6 /cm2/s] T6  i [10 8 /cm2/s]  i [10 9 /cm2/s] Be NO B

26 SSM (2000) The model by Bahcall and Pinsonneault 2000 is generally in agreement with data to the “1sigma”level Some possible disagreement just below the convective envelope (a feature common to almost every model and data set) Y BP2000 =0.244Y O =  Rb BP2000 -=0.714 Rb O =0.711  See Bahcall Pinsonneault and Basu astro-ph

27 Input and results of SSMs [units]BP2000FRANECGARSOM Z/X L[10^33erg/s] pp [10 10 /s/cm 2 ] Be [10 9 /s/cm 2 ] B [10 6 /s/cm 2 ] CNO [10 9 /s/cm 2 ] TcTc [10 6 K] ==

28 Calculated partial derivatives X Y S pp S 33 S 34 S 17 S 1,14 LZ/Xopaagedif pp Be B N O TcTcTcTc Values of dlnY/ dlnX computed by using models including element diffusion.

29 Calculated partial derivatives X Y S pp S 33 S 34 S 17 S 1,14 LZ/Xopaagedif pp0.114 (0.14) (-0.07) Be (-0.00) (0.69) 0.17 B (+0.01) N (1.01) 0.25 O (0.02) (-0.05) TcTcTcTc Values of dlnY/ dlnX computed by using models including element diffusion. For fluxes, values differing more than 10% from JNB values (in italics) are marked in red.

30 Dependence of CNO neutrinos *Adelberger compilation Source  S/Sdln  N /dlnS   /   dln  O /dlnS  O /  O S S S17**+0.14* Se Spp S1, * Com Opa Dif Lum  

31 The measured S 17 (0) as a function of time From JNB astro-ph/

32 NACRE compilation NACRE compilation adopted DB theory

33 Junghans et al DB theory

34 Hammache et al DB theory

35 Baby et al DB theory

36 Strieder et al.