The pp-chain and the CNO-cycle after KamLAND

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 S17,S34
  and S1,14 are particularly important now.

GF and BR LNGS 21-02-03
2
SNO the appearance experiment

• A 1000 tons heavy water detector sensitive to
  B-neutrinos by means of
• CC ned -gt p p e
• sensitive to ne only, provides a good
  measurement of ne spectrum with weak
  directionality
• NC nxd -gt p n nx
• Equal cross section for all n flavors. It
  measures the total 8B flux from Sun.
• ES nxe -gt e nx
• Mainly sensitive to ne, strong directionality.

The important point is that SNO can determine
both F(ne) and F(ne nm nt )
3
SNO results

• The measured total B neutrino flux is in
  excellent agreement with the SSM prediction

• About 2/3 of produced ne transform into nm and/or
  nt.
• The large mixing angle (LMA) solution is
  preferred by a global fit of Chlorine, Gallium,
  SuperK and SNO data.

(1s)
(1s)
LOW
JUST-SO
4
The first KamLAND results

• Source anti-ne from distant (100 km) nuclear
  reactors
• Detector 1Kton liquid scintillator where
• Anti-ne p -gt n e
• n p -gt d g
• Measure the energy released in the slowing down
  and annihilation of e
• EvisT2me in the presence of the 2MeV g ray.
• Observed/Expected 54/ (86-5.5)
• - gt Oscillation of reactor anti-ne proven
• Best fit Dm2 6.9 10-5 eV2 sin2 2q 0.91
  
• - gt LMA solution for solar neutrinos confirmed.

5
The impact of KamLAND first results on solar
neutrinos
Before
After
LMA
After KamLAND Dm2 is restricted to the region
(5-20)10-5 eV2.
Bahcall et al. hep-ph/0212147, Fogli et al.
hep-ph/0212127 .
6
Bruno Pontecorvo

• Neutron Well Logging - A New Geological Method
  Based on Nuclear Physics, Oil and Gas Journal,
  1941, vol.40, p.32-33.1942.
• An 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.

• The Cl-Ar method
• Neutrino sources (sun, reactors, accelerators)
• Neutrino oscillations

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 the Sun
9
The measured boron flux
BP2000 FRANEC GARSOM
FB 106s-1cm-2 5.05 5.20 5.30

• The total active FBF(ne nm nt) boron flux is
  now a measured quantity. By combining all
  observational data one has
• FB 5.05 (1 0.06) 106 cm-2s-1.
• The central value is in perfect agreement with
  the Bahcall 2000 SSM
• Note the present 1s error is DFB/FB 6
• In the next few years one can expect to reach
  DFB/FB3

Bahcall et al. hep-ph 0212147
10
The Boron Flux, Nuclear Physics and Astrophysics
FB
s33 s34 s17se7 spp Nuclear
astro

• FB depends on nuclear physics
• and astrophysics inputs
• Scaling laws have been found numerically and are
  physically understood
• FB FB (SSM) s33-0.43 s34 0.84 s171 se7-1
  spp-2.7
• com1.4 opa2.6 dif
  0.34 lum7.2
• 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.

Scaling laws derived from FRANEC models
including diffusion. Coefficients closer to those
of Bahcall are obtained if diffusion is neglected.
11
Uncertainties budget
Source DS/S(1s) DFB/FB
S33 0.06 0.03
S34 0.09 0.08
S17 0.14 -0.07 0.14 -0.07
Se7 0.02 0.02
Spp 0.02 0.05
Com 0.06 0.08
Opa 0.02 0.05
Dif 0.10 0.03
Lum 0.004 0.03

• Nuclear physics uncertainties, particularly on
  S17 and S34 , dominate over the present
  observational accuracy
• DFB/FB 6.
• The foreseeable accuracy DFB/FB 3 could
  illuminate about solar physics if a significant
  improvement on S17 and S34 is obtained.
• For fully exploiting the physics potential of a
  FB measurement with 3 accuracy one has to
  determine S17 and S34 at the level of 3 or
  better.

• LUNA gift
• Adelberger estimate see below
• by helioseismic const.
• gf et al.AA 342 (1999) 492
• See similar table in JNB, astro-ph/0209080

12
Progress on S17

• JNB and myself still use a conservative
  uncertainty (-24), however recently high
  accuracy determinations of S17 have appeared.
• Average from 5 recent determinations yields
• S17(0) 21.1 0.4 with c2/dof2
• If one omits Junghans et al. one finds
• S17(0) 20.5 0.5 with c2/dof1.2
• If we add in quadrature an error in theory of
  0.5 we get a consistent common value
• S17(0) 20.5 0.7 eV b

S17(0)eV b
Data published
Results of direct capture expts.
S17(0) eV b Ref.
Adel.-Review. 19-24 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, 041101 (2002)
Baby et al. 21.2 0.7 PRL. 90,022501 (2003)
The cross section values of this paper are
currently being revised ( K.A. Snover, private
communication).
See also Gialanella et al EPJ A7, 303 (2001)
13
Comparison between most recent data
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
Junghans et al.
Baby et al.
S17(0)22.3 0.7 eV b
S17(0)21.2 0.7 eV b
DB theory NPA 567, 341(1994)
14
Remark on S17 and S34
Source DS/S (1s) DFB/FB
S33 0.06 0.03
S34 0.09 0.08
S17 0.035 0.035
Se7 0.02 0.02
Spp 0.02 0.05
Com 0.06 0.08
Opa 0.02 0.05
Dif 0.10 0.03
Lum 0.004 0.03

• If really S17(0) 20.5 0.7 eV b this means a
  3.5 accuracy.
• The 9 error of S34 is the main source of
  uncertainty for extracting physics from Boron
  flux.
• LUNA results on S34 will be extremely important.

15
The central solar temperature
Source dlnT/dlnS b dlnFB/dlnSa a/b
S33 0 -0.43
S34 0 0.84
S17 0 1
Se7 0 -1
Spp -0.14 -2.7 19
Com 0.08 1.4 17
Opa 0.14 2.6 19
Dif 0.016 0.34 21
Lum 0.34 7.2 21

• The various inputs to FB can be grouped according
  to their effect on the solar temperature.
• All nuclear inputs (but S11) 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
• FB FB (SSM) T /T(SSM) 20.
• . S33-0.43 s340.84 s17 se7-1

• Boron neutrinos are excellent solar thermometers
  due to their high (20) power dependence.

16
Present and future for measuring T with
B-neutrinos

• At present, DFB/FB 6 and DSnuc/ Snuc 13
  (cons.) translate into
• DT/T 0.7
• the main error being due to S17 and S34.
• If nuclear physics were perfect (DSnuc/Snuc 0)
  already now we could have
• DT/T 0.3
• When DFB/FB 3 one can hope to reach
  (for DSnuc/Snuc 0)
• DT/T 0.15

17
The central solar temperature and helioseismology

• Helioseismology determines sound speed.
• The accuracy on its square is Du/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.

present DT/T future

• For the innermost part, neutrinos are now (DT/T
  0.7) almost as accurate as helioseismology
• They can become more accurate than
  helioseismology in the future.

18
The Sun as a laboratory for astrophysics and
fundamental physics
BP-2000 FRANEC GAR-SOM
T6 15.696 15.69 15.7

• 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)

19
Be neutrinos
Source DS/S (1s) DFBe/FBe DFB/FB
S33 0.06 0.03 0.03
S34 0.09 0.08 0.08
S17 0.14 -0.07 0.14 -0.07
Se7 0.02 0.02
Spp 0.02 0.02 0.05
Com 0.06 0.04 0.08
Opa 0.02 0.03 0.05
Dif 0.10 0.02 0.03
Lum 0.004 0.01 0.03

• - In the long run (Borexino KamLANDLENS) one
  can expect to measure FBe with an accuracy
  DFBe/FBe 5
• - FBe is insensitive to S17, however the
  uncertainty on S34 will become important.
• - FBe is less sensitive to the solar
  structure/temperature (FBe T10).
• An accuracy DFBe/FBe 5 will provide at best
• DT/T 0.5

• Remark however that Be and B bring information on
  (slightly) different regions of the Sun

20
CNO neutrinos, LUNA and the solar interior
Source DS/S (1s) DFN/FN DFO/FO
S33 0.06 0.001 0.0008
S34 0.09 0.004 0.003
S17 0.14 -0.07 0 0
Se7 0.02 0 0
Spp 0.02 0.05 0.06
S1,14 0.11 -0.46 0.09 -0.38 0.11 -0.46
Com 0.06 0.12 0.13
Opa 0.02 0.04 0.04
Dif 0.10 0.03 0.03
Lum 0.004 0.02 0.03

• 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

• The principal error source is S1,14. 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.

21
Does the Sun Shine by pp or CNO Fusion Reactions?
Bahcall, Garcia Pena-Garay Astro-ph 0212331

• Solar neutrino experiments set an upper limit
  (3s) 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?
• Are there additional energy losses, beyond
  photons and neutrinos?

22
Summary

• Solar neutrinos are becoming an important tool
  for studying the solar interior and fundamental
  physics
• Better determinations of S17, S34 and S1,14 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 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.

from Castellani et al. Phys. Rep. 281, 309
(1997)
25
Sensitivity to the central temperature
B
-1000 solar models without diffusion, with cross
sections and element abundances varied within
their uncertainties
from Bahcall Ulmer PRD 53, 4202 (1996)
26
SSM (2000)

• The model by Bahcall and Pinsonneault 2000 is
  generally in agreement with data to the
  1sigmalevel
• Some possible disagreement just below the
  convective envelope (a feature common to almost
  every model and data set)

YBP20000.244 YO 0.2490.003 RbBP2000-0.714
RbO 0.711 0.001

• See Bahcall Pinsonneault
• and Basu astro-ph 0010346

27
Input and results of SSMs
units BP2000 FRANEC GARSOM
Z/X 0.0230 0.0245 0.0245
L 1033erg/s 3.842 3.844 3.844
pp 1010/s/cm2 5.95 5.98 5.99
Be 109/s/cm2 4.77 4.51 4.93
B 106/s/cm2 5.05 5.20 5.30
CNO 109/s/cm2 1.03 0.98 1.08
Tc 106K 15.69 15.7
28
Calculated partial derivatives
X Y Spp S33 S34 S17 S1,14 L Z/X opa age dif
pp 0.114 0.029 -0.062 0 -0.019 0.73 -0.076 -0.12 -0.088 -0.02
Be -1.03 -0.45 0.87 0 -0.027 3.5 0.60 1.18 0.78 0.17
B -2.73 -0.43 0.84 1 -0.02 7.2 1.36 2.64 1.41 0.34
N -2.59 0.019 -0.047 0 0.83 5.3 1.09 1.82 1.15 0.25
O -3.06 0.013 -0.038 0 0.99 6.3 2.12 2.17 1.41 0.34
Tc -0.14 -.0024 0.0045 0 0.0033 0.34 0.078 0.14 0.083 0.016
Values of dlnY/ dlnX computed by using
models including element diffusion.
29
Calculated partial derivatives
X Y Spp S33 S34 S17 S1,14 L Z/X opa age dif
pp 0.114 (0.14) 0.029 -0.062 0 -0.019 0.73 -0.076 -0.12 -0.088 (-0.07) -0.02
Be -1.03 -0.45 0.87 0 -0.027 (-0.00) 3.5 0.60 1.18 0.78 (0.69) 0.17
B -2.73 -0.43 0.84 1 -0.02 (0.01) 7.2 1.36 2.64 1.41 0.34
N -2.59 0.019 -0.047 0 0.83 5.3 1.94 1.82 1.15 (1.01) 0.25
O -3.06 0.013 (0.02) -0.038 (-0.05) 0 0.99 6.3 2.12 2.17 1.41 0.34
Tc -0.14 -.0024 0.0045 0 0.0033 0.34 0.078 0.14 0.083 0.016

• 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
FN
FO
Source DS/S dlnFN/dlnS DFN/FN dlnFO/dlnS DFO/FO
S33 0.06 0.02 0.001 0.01 0.0008
S34 0.09 -0.05 0.004 -0.04 0.003
S17 0.14 -0.07 0 0 0 0
Se7 0.02 0 0 0 0
Spp 0.02 -2.6 0.05 -3.1 0.06
S1,14 0.11 -0.46 0.83 0.09 -0.38 0.99 0.11 -0.46
Com 0.06 1.9 0.12 2.1 0.13
Opa 0.02 1.8 0.04 2.2 0.04
Dif 0.10 0.25 0.03 0.34 0.03
Lum 0.004 5.3 0.02 6.2 0.03
Adelberger compilation
31
The measured S17(0) as a function of time
From JNB astro-ph/0209080
32
NACRE compilation
adopted DB theory
33
Junghans et al
DB theory
34
Hammache et al
2001
1998
DB theory
35
Baby et al
DB theory
36
Strieder et al.