Common problem against B and L genesis and its possible resolution M. Yoshimura

1. Common problem against B and L genesis and its possible resolutionM. Yoshimura • Introduction • 3 conditions for B asymmetry generation • Sources of Bnon-conservation at finite T GUT, electroweak ・　Scenario of original B-genesis ・　Thermal L-genesis and general remarks ・ 　Possible nightmare: gravitino problem ・　Way out • Conclusion

2. Why are we (as a form of matter)here ? • Despite that the law of microphysics is almost matter-antimatter symmetric, and • Despite that in the early universe antimatter production is energetically possible and equilibrium must have been established by the laws of gravity and thermodynamics, and • Despite that matter-antimatter pair annihilation is very effective

3. Mystery of our existence:Generation of B-asymmetry • Key quantity Is imbalance for matter a hint on some symmetry violation?

4. p/p Ratio Absence of antimatter and problem with symmetric cosmology • Observational evidence against symmetric cosmology near earth No evidence of from • Theoretical problem with B-symmetric cosmology much smaller than observed No working model of domain separation

5. How to produce the asymmetry：　3 conditions in the early universe Necessary ingredients

6. Sources of B nonconservation • GUT • Electroweak at high T: leading to L to B conversion @ • SUSY （Affleck-Dine mechanism)

8. Electroweak baryon nonconservation Electroweak damping Gauge and Higgs Electroweak baryon noncnoservation suppressed at T=0 by enhanced at finite T by barrier crossing Can destroy preexisting B and L while keeping B-L Mechanism due to level crossing of fermions caused by nontrivial gauge and higgs configuration of sphaleron and alike

9. Baryogenesis in standard model • unsuppressed at finite T • KM phase • Out of equilibrium: 1st order phase transition via bubble formation

10. Difficulties of EW B-genesis ・Out of equilibrium condition requires a large radiative correction to the Higgs potential to obtain a strong 1st order phase transition, but experimental Higgs mass bound > 115 GeV excludes this possibility • Magnitude too small due to KM phase alone

11. Electroweak redistribution of B and L For standard model of 3 generations B-L conserved and never washed out. Original B-generation does not survive, but redistributed Opens a new possibility of L-genesis

12. GUT generation of B with B-L nonconservation e.g. and its conjugate • SO(10) model is OK with constraint on neutrino masses • SU(5) is excluded

13. Out of equilibrium condition: case of heavy particle decay • One way decay, no inverse decay Otherwise, Boltzmann suppression by Typically leading to Need for high unification scale Reheating after inflation

14. In GUT view, • We are here, because matter that makes up us is ultimately unstable ! But, lifetime of proton typically

15. L genesis and B conversion • L-genesis of amount first and electroweak conversion into B, via For standard model of 3 generations Interesting in view of possible connection to observed neutrino masses

16. Neutrino physics Cosmic rays • Neutrino oscillation Neutrinos Neutrinos Upward Downward • Evidence of neutrino mass! Cosmic rays

17. Likely mechanism of small neutrino mass generation • Seesaw mechanism Heavy Majorana type of masses of neutrino partner, independent of standard theory of particle physics, generates a tiny left-handed neutrino masses and mixing a la • Necessarily violates lepton number conservation

18. Thermal L genesisFukugita-Yanagida • Minimal extention of standard model with seesaw Right-handed Majorana decay CP asymmetry with neutrino mass matrix For 3 R-Majoranas = CP phase

19. Great impacts on neutrino masses and thermal history of universe • Connection to neutrino masses heaviest neutrino (WMAP 0.23eV) lightest R-neutrino • Reheat temperature With hierarchy of masses, dependence on 3 parameters Giudice et al

20. Delicacy of CP：　Quantum interference Baryon excess from a pair of particle and antiparticle process, e.g. CP violation Rescattering phase Interference computed by Landau-Cutkovsky rule 　　　　　　　　　　　　　　　　　　　　　　　　　　＝

21. Gravitino problem: a possible nightmare both for GUT B- and L-genesis • Superpartner of graviton mass lifetime • Usual estimate of gravitino abundance and constraint from nucleosynthesis, including hadronic decay Possible to produce heavy　　　　 　　 ？

22. My favorite scenario for resolution • Both baryon asymmetry and gravitino abundance was diluted before thermalization period after its violent, initial production stage during preheating

23. Preheating: new understanding of entropy production before thermalization stage • Non-perturbative effect of parametric resonance, leading to Complicated high energy phase of reheating, i.e. preheating、 may be used for dilution of gravitino bundance Common to copious non-thermal production of R-Majorana neutrino for L-genesis

24. Theory of particle production with chaotic potential • Inflaton field oscillation given by (spatially homogeneous, periodic) Interaction by Producing a pair of particles For each momentum mode of massive particle

25. Non-perturbative effect of parametric resonance, producing large mass particles ・n-th band contribution like • Large mass production possible if with large n • Perturbative Born decay; from E-conservation

26. Preheating stage and gravitino abundance • e.g. B-generation during preheating and • gravitino abundance lowed by perturbative estimate is possible

27. Summary on B – L genesis • (B-L) genesis is a great hint on physics beyond the standard model, linking the micro and the macro worlds • B-genesis still alive, waiting for nucleon decay • L-genesis interesting due to its possible connection to the neutrino sector and lepton flavor violation • Watch out gravitino overproduction • Some new idea necessary for relation to low energy CP violation in K and B systems