Solar Neutrino Physics

A guide to the fascinating interplay between particle physics and astrophysics that highlights the discovery of neutrino oscillations

Written by three international experts on the topic,Solar Neutrino Physics offers a review of the status of solar physics with its strong link to neutrino physics. The book explores constitutive physics and the governing equations of standard solar models. The authors also review the theory of neutrinos in the Standard Model and the related detector experiments. The book contains a summary of the results from various experiments and develops a coherent view of the current state-of-the-art of solar neutrino physics.

Solar Neutrino Physics shows how solar models can be calibrated with the observational constraints of the age, mass, radius, and luminosity of the sun. The authors present general evolutionary properties of the sun as a star, past and future. They also discuss the solar neutrino production via the pp-chains and CNO-cycle, including the important role of the chemical composition of the sun. A very important source of information about the solar interior is offered by helioseismology, the study of solar oscillations. This important book:

• Presents a high-level overview of the field of solar neutrino physics
• Brings together data and their interpretation of results obtained at various solar neutrino observatories
• Combines the theory of nuclear reactions with solar neutrino experiments
• Contains a review of SNO+, JUNO, LENA, Hyper-Kamiokande, and DUNE.

Written for astronomers, physicists, and high energy physicists,Solar Neutrino Physics contains a review of the field of neutrino physics, the relevant equations, and the impact of matter on the behavior of neutrino oscillations.

Lothar Oberauer is professor for Astroparticle physics at the Technical University of Munich, Germany.

Aldo Ianni is a senior researcher and head of Research Division at the Gran Sasso Laboratory, Italy.

Aldo Serenelli is Tenured Researcher at the Institute of Space Sciences, in Bellaterra, near Barcelona, Spain.

1 Introduction1

2 Solar Structure and Evolution3

2.1 Equations of Stellar Structure and Evolution 3

2.1.1 Mechanical Structure 3

2.1.2 Energy Conservation and Transport 5

2.1.2.1 Energy Transport by Radiation and Conduction 5

2.1.2.2 Criterion for Dynamical Instability 7

2.1.2.3 Energy Transport: Convection 9

2.1.3 Changes in Chemical Composition 11

2.1.3.1 Convective Mixing 11

2.1.3.2 Changes in Chemical Composition: Atomic Diffusion 12

2.1.3.3 Changes in Chemical Composition: Nuclear Reactions 15

2.1.3.4 Changes in Chemical Composition: Putting Everything Together 16

2.1.4 Full Set of Equations and Boundary Conditions 17

2.2 Constitutive Physics 18

2.2.1 Equation of State 18

2.2.2 Radiative Opacities 21

2.2.3 Nuclear Reaction Rates 25

2.3 Calibrating Standard Solar Models 31

2.3.1 Observational Constraints 31

2.3.1.1 Age, Mass, Radius, and Luminosity 31

2.3.1.2 Surface Composition 32

2.3.2 Adjusting the Free Parameters 35

2.4 Standard Solar Models 36

2.4.1 Previous and Future Evolution 36

2.4.2 The Sun Today: An Overview 39

2.5 Solar Neutrinos 42

2.6 Helioseismology 48

2.6.1 Overview 48

2.6.2 Global Structure Inversions 51

2.6.3 Other Constraints 53

2.7 Solar Abundance Problem 54

2.8 Uncertainties in SSMs 58

2.8.1 Uncertainties in SSM Inputs 58

2.8.1.1 Nuclear Reaction Rates 58

2.8.1.2 Microscopic Diffusion 59

2.8.1.3 Radiative Opacities 59

2.8.1.4 Solar Radius, Luminosity, and Age 59

2.8.1.5 Solar Composition 59

2.8.1.6 Equation of State 60

2.8.2 Global Uncertainties in SSMs 60

2.8.2.1 Nuclear Reaction Rates 61

2.8.2.2 Constitutive Physics 61

2.8.2.3 Element Abundances 62

2.9 Solar Models Beyond the SSM 62

2.9.1 Nonstandard Solar Physics 63

2.9.2 Nonstandard Particle Physics 65

3 Neutrino Physics69

3.1 Neutrinos in the Standard Model 69

3.2 Neutrino Oscillations 75

3.3 Matter Effects 80

3.4 Neutrino Oscillation Experiments 84

3.4.1 Atmospheric Neutrinos 84

3.4.2 Long Baseline Accelerator Neutrinos 92

3.4.2.1 Long Baseline Experiments and𝜃1397

3.4.3 Reactor Neutrinos 100

3.5 Conclusions and Open Questions 109

3.5.1 What is the Absolute Neutrino Mass Scale? 111

3.5.2 Are Neutrinos Majorana or Dirac Particles? 120

3.5.3 What is the Neutrino Mass Ordering and How Large is CP-𝛿? 127

3.5.4 Are There Sterile Neutrinos? 135

4 Solar Neutrino Experiments139

4.1 Introduction 139

4.2 The37Cl Experiment 141

4.3 Kamiokande-II/III 145

4.4 The71Ga Experiments 153

4.5 Super-Kamiokande 162

4.6 SNO 169

4.7 Borexino 178

4.8 Summary and Open Questions 191

5 Future Solar Neutrino Experiments195

5.1 SNO+ 196

5.2 JUNO and LENA 199

5.3 Hyper-Kamiokande 204

5.4 DUNE 206

References 209

Index 221