Baryon Asymmetry in Particle Physics and Cosmology

1. Particle Physicsand Cosmology Baryon asymmetry

6. Boltzmann equation in terms of cross section .

7. dimensionless inverse temperature m : particle mass small x : particle is relativistic x<3 large x : particle is non-relativistic x>3 dimensionless time variable in units of particle mass m

8. particle number per entropy

9. cold relic fraction not necessarily order one !

10. cold relic abundance ,mass and cross section (m,σA) m inversely proportional to cross section , plus logarithmic dependence of xf

11. baryon relics in baryon symmetric Universe observed : Y = η ≈ 10 -10

12. baryons : the matter of stars and humans Ωb = 0.045

13. Abundancies of primordial light elements from nucleosynthesis A.Coc

14. primordial abundances for three GUT models present observations : 1σ He D Li T.Dent, S.Stern,…

15. present baryon number

17. anti-baryons in baryon asymmetric Universe

18. conserved baryon asymmetry no baryon number violating processes in standard model of particle physics at energy below 1 GeV baryon asymmetry must exist at T = 1 GeV

19. high temperature baryon problem

21. baryon number violation in standard model • baryon number is global symmetry of interactions in the standard model • violated by quantum anomaly ( no anomalies possible for local symmetries : corresponding charge , like electric charge , exactly conserved ) • sphaleron processes generate strong baryon number violating processes at temperatures above 100-200 GeV

22. baryon number violation in standard model no chemical potential for baryon number

23. thermal equilibrium in absence of chemical potential

25. baryogenesis

27. Sakharov’s conditions forbaryogenesis • baryon number violation interactions • charge conjugation violating interactions • CP – violating interactions • non – equilibrium process

28. baryon number violating processin Grand Unified Theories ( GUT )

29. baryon number violating processin Grand Unified Theories ( GUT )

30. not good enough : B asymmetry will be washed out later by sphaleron processes no B-L asymmetry is produced

31. leptogenesis or late baryogenesis

32. leptogenesis • B – L is conserved quantum number in standard model • sphaleron processes transmute lepton asymmetry into baryon asymmetry • a fraction of primordial B-L asymmetry appears as baryon asymmetry • primordial asymmetry protected from wash out by sphaleron processes ( B-L )

33. leptogenesis • non – equilibrium decay of heavy neutrinos • non – equilibrium production after inflation during entropy production of the Universe

34. baryogenesis during electroweak phase transition ?

35. Sakharov’s conditions forbaryogenesis during electroweak phase transition • baryon number violation interactions ☺ • charge conjugation violating interactions ☺ • CP – violating interactions ☺ • non – equilibrium process ☺

37. cosmological phase transitions

38. cosmological phase transitions

44. first order cosmological phase transitions

45. chaos in the Universe

48. baryogenesis during electroweak phase transition • strongly first order electroweak phase transition can generate baryon asymmetry if CP violation is sufficiently strong • no efficient baryogenesis for weak first order phase transition, second order phase transition or crossover • presumably too little CP violation in SM ( not definitely settled )

49. electroweak “phase transition “in standard model is crossover ! perhaps strong first order transition in supersymmetric extensions of standard model

50. standard model of particle physics and cosmology • no candidate for dark matter • no baryon asymmetry • no massive neutrinos