Leptogenesis Koichi Hamaguchi (University of Tokyo) Revealing the history of the universe with underground particle and nuclear research 2019 @ Tohoku Univ., March. 7, 2019. Mostly review See the poster by + partially based on Shih-Yen Tseng K. Asai, KH, N. Nagata, S. Tseng, K. Tsumura, [arXiv:1811.07571] tomorrow! K. Asai, KH, N. Nagata, [arXiv:1705.00419]
Plan Baryon Asymmetry of the Universe Why ``Lepto”genesis? Right-handed Neutrino’ s triple role Various Leptogenesis scenarios Predictions of minimal gauged U(1)L α -L β models Summary � 2
Plan Baryon Asymmetry of the Universe Why ``Lepto”genesis? Right-handed Neutrino’ s triple role Various Leptogenesis scenarios Predictions of minimal gauged U(1)L α -L β models Summary � 2
In the very early Universe,.... 0.000001 sec 1 sec 380,000 yrs 1.4x10 10 yrs http://pdg.ge.infn.it/particleadventure/frameless/chart_cutouts/universe_original.pdf
In the very early Universe,.... The number of particles and anti-particles were almost the same. matter antimatter
In the very early Universe,.... The number of particles and anti-particles were almost the same. But there was tiny excess of matter over anti-matter. matter antimatter O(10 -9 )
In the very early Universe,.... The number of particles and anti-particles were almost the same. When the Universe got cooler, they pair-annihilated,.. matter antimatter O(10 -9 )
In the very early Universe,.... The number of particles and anti-particles were almost the same. When the Universe got cooler, they pair-annihilated,.. matter antimatter O(10 -9 ) matter - antimatter annihilation γ γ
In the very early Universe,.... The number of particles and anti-particles were almost the same. When the Universe got cooler, they pair-annihilated,.. matter antimatter O(10 -9 )
In the very early Universe,.... The number of particles and anti-particles were almost the same. When the Universe got cooler, they pair-annihilated,.. only matter remains (no antimatter) All of us （ Galaxy, the Earth, the human beings,...) are made from this leftover matter.
Puzzle How was the initial excess of matter created ? matter antimatter O(10 -9 )
Puzzle How was the initial excess of matter created ? matter antimatter O(10 -9 ) Something beyond the Standard Model is necessary.
Observations (two independent evidences) 24. Big-Bang nucleosynthesis 3 He4 (1) Big Bang Nucleosynthesis (BBN) (cosmic time about 1 sec) D Li7 Figure 24.1: The primordial abundances of 4 He, D, 3 He, and 7 Li as predicted by the standard model of Big-Bang nucleosynthesis—the bands show the 95% CL range [5]. Boxes indicate the observed light element abundances. The narrow vertical band indicates the CMB measure of the cosmic baryon density, while the wider band indicates the BBN concordance range (both at 95% CL). [Particle Data Group] (2) Cosmic Microwave background October 18, 2016 13:34 (cosmic time about 400,000 yrs) (68%) [Planck 2015] � 8
When was the Baryon Asymmetry of the Universe generated? time temperature ?? ?? Inflation T R Reheating sometime ≈ in this range 100 GeV Electroweak phase transition 1 GeV QCD phase transition 1 MeV Big Bang Nucleosynthesis 1 sec ≈ 24. Big-Bang nucleosynthesis 3 400,000 yrs 3000 K Last Scattering Surface ≈ CMB Figure 24.1: The primordial abundances of 4 He, D, 3 He, and 7 Li as predicted by 14 billion yrs 3 K Now the standard model of Big-Bang nucleosynthesis—the bands show the 95% CL range [5]. Boxes indicate the observed light element abundances. The narrow vertical band indicates the CMB measure of the cosmic baryon density, while the wider band indicates the BBN concordance range (both at 95% CL). October 18, 2016 13:34 � 9
Plan Baryon Asymmetry of the Universe Why ``Lepto”genesis? Right-handed Neutrino’ s triple role Various Leptogenesis scenarios Predictions of minimal gauged U(1)L α -L β models Summary � 10
<latexit sha1_base64="s1+uKM9Mlgh8oPmvonEvfK8vjY=">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</latexit> <latexit sha1_base64="s1+uKM9Mlgh8oPmvonEvfK8vjY=">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</latexit> <latexit sha1_base64="s1+uKM9Mlgh8oPmvonEvfK8vjY=">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</latexit> <latexit sha1_base64="s1+uKM9Mlgh8oPmvonEvfK8vjY=">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</latexit> Why ``Lepto”genesis? Within the Standard Model,… Both Baryon # (B) and Lepton # (L) are conserved at classical level. ∂ µ J µ B = ∂ µ J µ L = 0 However, B and L are violated at quantum level! [’ t Hooft,’76] g 2 @ µ J µ B = @ µ J µ 32 ⇡ 2 ✏ µ νρσ Tr F µ ν F ρσ 2 6 = 0 L = N f Note: B-L is conserved ∂ µ ( J µ B − J µ L ) = 0 Although there is essentially no effect at low energy,… L ∼ e − 16 π 2 /g 2 2 ∼ 10 − 170 Γ / B,/ � 11
Why ``Lepto”genesis? Within the Standard Model,… At high temperature, T >> 100 GeV , B and L violating processes (sphaleron) become very rapid, and in thermal equilibrium! [Kuzmin, Rubakov, Shaposhnikov,ʼ85] Sphaleron process processes involving 9 quarks (B=3) and 3 leptons (L=3). Note that B-L is conserved. [fig. from W.Buchmuller, 1210.7758] � 12
Therefore, if the Baryon asymmetry is generated via a B-L conserving process,… e.g, GUT baryogenesis B =0 L =0 B =100 L =100 � 13
Therefore, if the Baryon asymmetry is generated via a B-L conserving process,… Finally B=0 at equilibrium. e.g, GUT baryogenesis B =0 L =0 B =100 L =100 B =0 L =0 sphaleron process � 14
Therefore, if the Baryon asymmetry is generated via a B-L conserving process,… Finally B=0 at equilibrium. e.g, GUT baryogenesis B =0 L =0 B =100 L =100 B =0 L =0 sphaleron process B-L violating process is necessary. � 14
Sakharov’ s 3 conditions ・ Baryon number (B) violation B-L violation ・ C and CP violation ・ Out-of-equilibrium � 15
Sakharov’ s 3 conditions ・ Baryon number (B) violation B-L violation ・ C and CP violation ・ Out-of-equilibrium Baryogenesis can work, not only via B-violation, but also via L-violation. and L-violation implies,… Majorana neutrino, and 0 νββ decay!! � 15
Lepgogenesis [Fukugita, Yanagida, ʼ86] generate Lepton asymmetry L =-100 B =0 L =0 B =0 right-handed neutrino decay (CP-violating) N N ≠ - h h e e � 16
Lepgogenesis [Fukugita, Yanagida, ʼ86] Then, B ≠ 0 remains generate Lepton asymmetry at equilibrium! L =-100 L =-65 B =0 L =0 B =0 B =35 right-handed neutrino decay sphaleron process (CP-violating) N N ≠ - h h e e � 17
Plan Baryon Asymmetry of the Universe Why ``Lepto”genesis? Right-handed Neutrino’ s triple role Various Leptogenesis scenarios Predictions of minimal gauged U(1)L α -L β models Summary � 18
Right-handed Neutrino’s triple role Just by adding (2 or) 3 heavy right-handed neutrinos to the Standard Model,… L = L SM + 1 2 N R ( i/ @ + M R ) N R + y ν N R ` L H + h.c. Higgs New Physics RH neutrino
Right-handed Neutrino’s triple role Just by adding (2 or) 3 heavy right-handed neutrinos to the Standard Model,… (1) small neutrino masses (2) matter unification L = L SM + 1 2 N R ( i/ @ + M R ) N R + y ν N R ` L H + h.c. in 16 of SO(10) Higgs New Physics (3) Leptogenesis RH neutrino
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