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Primordial Nucleosynthesis - the Origin of the Lightest Elements

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Primordial Nucleosynthesis - the Origin of the Lightest Elements Primordial Nucleosynthesis - The Origin of the Lightest Elements Marcel Krause Institute for Theoretical Physics (ITP), Karlsruhe Institute of Technology (KIT) Institute for Theoretical Physics May 13, 2019 The Big Bang Theory in a Nutshell Primordial Nucleosynthesis - Overview Primordial Nucleosynthesis – Processes Measurements of the Abundance of the Lightest Elements Results of the Measurements KIT – University of the State of Baden-Wuerttemberg and National Research Center of the Helmholtz Association www.kit.edu The Big Bang Theory in a Nutshell geometrization of gravity: May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 2 The Big Bang Theory in a Nutshell geometrization of gravity: Einstein Field Equations : Ricci tensor (curvature of space-time) : Ricci scalar (curvature of space-time) : metric tensor (metric of space-time) : Einstein tensor (manifold) : energy-momentum tensor (“source” of the curvature of space-time) : cosmological constant (vacuum state dark energy) : gravitational constant : speed of light May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 3 The Big Bang Theory in a Nutshell important parameters for an expanding universe: scale factor proper (physical) distance co-moving (reference) distance (per definition, today we have ) May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 4 The Big Bang Theory in a Nutshell important parameters for an expanding universe: scale factor proper (physical) distance co-moving (reference) distance (per definition, today we have ) Hubble parameter today: May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 5 The Big Bang Theory in a Nutshell important parameters for an expanding universe: scale factor proper (physical) distance co-moving (reference) distance (per definition, today we have ) Hubble parameter today: normalized spatial curvature parameter May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 6 The Big Bang Theory in a Nutshell critical density for : (today roughly 5 hydrogen atoms per m³) May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 7 The Big Bang Theory in a Nutshell critical density for : (today roughly 5 hydrogen atoms per m³) evolution of the universe: Parametrized Friedmann Lemaître Equations : energy densities of radiation (R), matter (M), curvature (k) and the vacuum ( ) May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 8 The Big Bang Theory in a Nutshell critical density for : (today roughly 5 hydrogen atoms per m³) evolution of the universe: Parametrized Friedmann Lemaître Equations : energy densities of radiation (R), matter (M), curvature (k) and the vacuum ( ) primordial nucleosynthesis! May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 9 Primordial Nucleosynthesis - Overview also known as Big Bang nucleosynthesis (BBN) May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 10 Primordial Nucleosynthesis - Overview also known as Big Bang nucleosynthesis (BBN) explains the creation of the lightest elements (H, d, ³He, 4He, 7Li) directly after the Big Bang temperature of the universe: between 1011 K and 109 K May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 11 Primordial Nucleosynthesis - Overview also known as Big Bang nucleosynthesis (BBN) explains the creation of the lightest elements (H, d, ³He, 4He, 7Li) directly after the Big Bang temperature of the universe: between 1011 K and 109 K age of the universe: between 0.01 s and 3 min after the Big Bang famous “first three minutes” of the universe (cf. Weinberg etc.) May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 12 Primordial Nucleosynthesis - Overview temperature 2.725 K 105 K CMB 109 K 1012 K May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 13 Primordial Nucleosynthesis - Motivations BBN is strongly supported by the Big Bang theory explanation of the origin of the lightest elements May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 14 Primordial Nucleosynthesis - Motivations origin of the lightest elements (H, d, ³He, 4He, 7Li) May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 15 Primordial Nucleosynthesis - Motivations origin of the lightest elements (H, d, ³He, 4He, 7Li) May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 16 Primordial Nucleosynthesis - Motivations BBN is strongly supported by the Big Bang theory explanation of the origin of the lightest elements verifiable through experimental observations May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 17 Primordial Nucleosynthesis - Motivations BBN is strongly supported by the Big Bang theory explanation of the origin of the lightest elements verifiable through experimental observations determination of the baryonic energy density determination of the ratio of baryons and photons Ratio of Baryons and Photons May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 18 Primordial Nucleosynthesis – Four Stages Stage 0: Quark Gluon Plasma quasi-free quarks and gluons (free of confinement) equilibrium state terminates in hadronization formation of protons and neutrons May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 19 Primordial Nucleosynthesis – Four Stages Stage I: Thermodynamic Equilibrium dominant particles: equilibrium state between protons and neutrons continuous transformation via the weak interaction May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 20 Primordial Nucleosynthesis – Four Stages Stage I: Thermodynamic Equilibrium difference in rest energy May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 21 Primordial Nucleosynthesis – Four Stages Stage I: Thermodynamic Equilibrium difference in rest energy proton and neutron are two states of one isospin doublet Boltzmann Distribution in Thermal Equilibrium : Boltzmann constant connection between neutron-proton ratio and statistical physics May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 22 Primordial Nucleosynthesis – Four Stages Stage I: Thermodynamic Equilibrium reaction rate of the weak processes: ( : Fermi constant) May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 23 Primordial Nucleosynthesis – Four Stages Stage I: Thermodynamic Equilibrium reaction rate of the weak processes: ( : Fermi constant) expansion rate of the universe: May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 24 Primordial Nucleosynthesis – Four Stages Stage I: Thermodynamic Equilibrium reaction rate of the weak processes: ( : Fermi constant) expansion rate of the universe: ratio of reaction and expansion rates: weak processes freeze out at roughly neutron-proton ratio stabilizes and the equilibrium is broken May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 25 Primordial Nucleosynthesis – Four Stages Stage II: Freeze-Out of the Weak Processes thermodynamic equilibrium between neutrons and protons breaks decay of free neutrons Neutron-Proton Ratio at the Freeze-Out Temperature May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 26 Primordial Nucleosynthesis – Four Stages Stage III: Beta Decay of the Free Neutrons mean lifetime of free neutrons: Decay Process of Free Neutrons May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 27 Primordial Nucleosynthesis – Four Stages Stage III: Beta Decay of the Free Neutrons mean lifetime of free neutrons: Decay Process of Free Neutrons no light elements are produced yet why? May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 28 Primordial Nucleosynthesis – Four Stages deuterium (d) is the next-to-lightest isotope to be produced May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 29 Primordial Nucleosynthesis – Four Stages deuterium (d) is the next-to-lightest isotope to be produced binding energy of deuterium: ratio of photons with the same energy at (high-end tail): May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 30 Primordial Nucleosynthesis – Four Stages deuterium (d) is the next-to-lightest isotope to be produced binding energy of deuterium: ratio of photons with the same energy at (high-end tail): remember: baryon-to-photon ratio is for each produced deuteron, one high-energy photon is present thermal equilibrium between deuteron production and spallation neither stable deuterium nor the other light elements can be produced yet stable deuterium is needed for other elements: “deuterium bottleneck” May 13, 2019 M. Krause: Primordial Nucleosynthesis – The Origin of the Lightest Elements ITP, KIT 31 Primordial Nucleosynthesis
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