The pp-chain (and the CNO-cycle) after SNO and KamLAND

1
The pp-chain (and the CNO-cycle) after SNO and
KamLAND
Fourth International Conference on Physics Beyond
the Standard Model BEYOND THE DESERT 03 Castle
Ringberg, Tegernsee, Germany 9-14 June 2003
Barbara Ricci, University of Ferrara and INFN
2
FAPG
Ferrara AstroParticles Group (University and INFN)
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Outline

• Boron-neutrinos after SNO and KamLAND
• What can we learn from B-neutrinos?
• What have we learnt from Helioseismology?
• The Sun as a laboratory for fundamental physics

• Main messages
• Neutrinos are now probes of the solar interior
• accurate determinations of S17,S34 and S1,14 are
  particularly important now.

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The new era of neutrino physics

• 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.

Sun
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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 hope to reach DFB/FB3

Bahcall et al. astro-ph/0212147 and
astro-ph/0305159
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The Boron Flux, Nuclear Physics and Astrophysics
FB
s33 s34 s17se7 s11 Nuclear

• 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
  s11-2.7
• 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.

astro
Scaling laws derived from FRANEC models
including diffusion. Coefficients closer to those
of Bahcall are obtained if diffusion is neglected.
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Uncertainties budget
DFB/FB
DS/S(1s)
Source
0.03
0.06
S33

• Nuclear physics uncertainties, particularly on
  S17 and S34 , dominate over the present
  observational accuracy
• DFB/FB 6 (1s ).
• 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.

0.08
0.09
S34
0.14 -0.07
0.14 -0.07
S17
0.02
0.02
Se7
0.05
0.02
S11
0.08
0.06
Com
0.05
0.02
Opa
0.03
0.10
Dif
0.03
0.004
Lum

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

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Progress on S17
S17(0)eV b

• Adelberger and NACRE use a conservative
  uncertainty (9),
• Recently high accuracy determinations of S17 have
  appeared.
• Average from 5 recent determinations yields
• S17(0) 21.1 0.4 (1s)
• In principle an accuracy of 2 has been
  reached, however c2/dof2 indicating some
  tension among different data.

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)
See also Davids Typel (2003) 19 0.5 eVb
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Remark on S34
DFB/FB
DS/S (1s)
Source
0.03
0.06
S33
0.08
0.09
S34

• If really S17(0) has a 2 accuracy, the 9
  error of S34(0) is the main source of uncertainty
  for extracting physics from Boron flux.

0.02
0.02
S17
0.02
0.02
Se7
0.05
0.02
S11
0.08
0.06
Com
0.05
0.02
Opa
0.03
0.10
Dif
0.03
0.004
Lum

• LUNA results on S34 will be extremely important.

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Sensitivity to the central temperature
Castellani et al. 97
Bahcall and Ulmer. 96

• Boron neutrinos are mainly determined by the
  central temperature, almost independently in the
  way we vary it.
• (The same holds for pp and Be neutrinos)

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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
S11 -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
  pp-chain branches without changing solar
  structure.
• The effect of the others can be reabsorbed into a
  variation of the central solar temperature
• FB FB (SSM) Tc /Tc(SSM) 20.
• . S33-0.43 S340.84 S17
  Se7-1

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

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Present and future for measuring T with
B-neutrinos

• At present, DFB/FB 6 and DSnuc/ Snuc 12
  (cons.) translate into
• DTc/Tc 0.7
• the main error being due to S17 and S34.
• If nuclear physics were perfect (DSnuc/Snuc 0)
  already now we could have
• DTc/Tc 0.3
• When DFB/FB 3 one can hope to reach
  (for DSnuc/Snuc 0)
• DTc/Tc 0.15

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Helioseismic observables
u

• From the measurements of
• p-modes one derives
• a)sound speed squared uP/r
• (1s) accuracy 0.1 1, depending on the
  solar region

b) properties of the convective envelope Rb /Ro
0.711(1 0.14) (1s) Yph0.249 (11.4)
See e.g. Dziembowski et al. Astr.Phys. 7 (1997) 77
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SSM and helioseismology

• Standard solar models are generally in agreement
  with data to the (1s) level e.g. BP2000
• Some possible disagreement just below the
  convective envelope (a feature common to almost
  every model and data set)

YBP20000.244 Y 0.2490.003 RbBP20000.714
Rb0.711 0.001
BP2000Bahcall et al. ApJ 555 (2001) 990
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Helioseismology constrains solar models and
solar temperature (1)

• Temperature of the solar interior cannot be
  determined directly from helioseismology
  chemical composition is needed (uP/r T/ m)
• But we can obtain the range of allowed values of
  Tc by using th following approach
• build solar models by varying the solar inputs
  which mainly affect Tc (S11, chemical
  composition, opacity)
• select those models consistent with helioseismic
  data(sound speed profile, properties of the
  convective envelope)

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Examples
Z/X
S11
The metal content is constrained at the 5 level
(1s)
S11 is constrained at 2 level (1s)

• Actually one has to consider
• 1) all parameters which affect Tc in the proper
  way (compensation effects)
• 2) not only sound speed, but above all the
  properties of the convective envelope
  ...

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Helioseismology constrained solar models and
solar temperature (2)

• Temperature of the solar interior cannot be
  determined directly from helioseismology
• So - if we build solar models by varying the
  solar inputs which mainly affect Tc
• -and select those models consistent with
  helioseismic data(sound speed profile, properties
  of the convective envelope)
• We find

Helioseismic constraint DTc/Tc 0.5
BR et al. PLB 407 (1997) 155
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Comparison between the two approaches

• Helioseismic constrained solar models give
• DTc/Tc 0.5
• Boron neutrinos observation translate into
• DTc/Tc 0.7
• (main error being due to S17 and S34)
• For the innermost part of the sun, neutrinos are
  now almost as accurate as helioseismology
• (They can become more accurate than
  helioseismology in the near future)

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

• An accurate measurement of the solar temperature
  near the center 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 emission)
• Dark matter
• (if trapped in the Sun it could change the solar
  temperature very near the center)

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

• In the long run (KamLAND BorexinoLENS) 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

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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.

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Summary

• Solar neutrinos are becoming an important tool
  for studying the solar interior and fundamental
  physics
• At present they give information about solar
  temperature as accurate as helioseismology does
• Better determinations of S17, S34 and S1,14 are
  needed for fully exploiting the physics potential
  of solar neutrinos.
• All this could bring us towards fundamental
  questions
• Is the Sun fully powered by nuclear reactions?
• Is the Sun emitting something else, beyond
  photons and neutrinos?

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Appendix
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pp-chain
99,77 p p ? d e ?e E? ? 0,42 MeV
0,23 p e - p ? d ?e E? 1,44 MeV
S(0)(4,00?0,068)?10-22 KeV b
2?10-5
84,7
d p ? 3He ?
13,8
3He 4He ? 7Be ? S(0)(0,52 ? 0,02) KeV b
0,02
13,78
7Be e- ? 7Li ? ?e E? ? 0,86 MeV
7Be p ? 8B ?
3He 3He ? ? 2p S(0)(5,4 ? 0,4) MeVb
3He p? ? e ?e E? ? 18 MeV
7Li p ? ? ?
pp I
pp III
pp II
hep
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Observations

• On Earth network of telescopes at different
  longitudines -Global Oscillation Network
  Group (GONG)
• -Birmingham Solar Oscillations Network (BiSON).

GONG

• From satellite
• since 1995 SoHo (Solar and Heliospheric
  Observatory)

D1.5 106 km
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Solar rotation

• Solar surface does not rotate uniformely T24
  days (30 days) at equator (poles).

days

• Helioseismology (after 6 years of data taking)
  shows that below the convective region the sun
  rotates in a uniform way

• Note Erot 1/2 m wrotR2 0.02 eV Erot ltlt
  KT

http//bigcat.phys.au.dk/helio_outreach/english/
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Magnetic field
Radiative zone B lt 30MG, mn gt 5 10-15
mB Tachocline B lt 30000G, mn gt 3 10-12 m
B External zone, flux tube, B 4000G

• From the observation of sunspots
  number a 11 year solar cycle has
  been determined
  (Sunspots very intense magnetic
  lines of force (3kG) break
  through
  the Sun's surface)
• the different rotation between
  convection and radiative regions could generate
  a dynamo mechanism
• Blt 30 kG near the bottom of the convective zone.
  ( e.g. Nghiem, Garcia, Turck-Chièze,
  Jimenez-Reyes, 2003)
• Blt 30 MG in the radiative zone
• Anyhow also a 106G field give
  an energy contribution ltlt KT

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Inversion method

• Calculate frequencies wi as a function of u
• wi wi(uj) jradial coordinate
• Assume Standard Solar Model as linear deviation
  around the true sun
• wiwi, sun Aij(uj-uj,sun)
• Minimize the difference between the measured Wi
  and the calculated wi
• In this way determine Duj uj -uj, sun

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Does the Sun Shine by pp or CNO Fusion Reactions?
Bahcall, Garcia Pena-Garay PRL 2003

• 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.