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1 Affleck-Dine Leptogenesis induced by the Flaton of Thermal Inflation Wan-il Park KAIST Korea Advanced Institute of Science and Technology Based on JHEP 0411:046,2004(hep-ph/0406136) Summer Institute 2006: August 23-30, 2006 APTCP, Pohang, Korea
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2 Contents Introduction Motivation Model Dynamics Summary & Conclusion
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3 Observed asymmetry Matter-antimatter asymmetry - Is this given as initial condition of universe? Direct measurement (galaxy survey) Abundances of light elements (BBN) Density perturbation (CMBR) } Inflation Dynamical generation of asymmetry is required after inflation: Baryogenesis !!! Introduction
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4 Basic ingredients of baryogenesis (Sakharov, 1967) Baryon number violation C and CP-violation Departure from thermal equilibrium GUT baryogenesis, leptogenesis (Yoshimura, 1978; Fukugita and Yanagida, 1986) uses heavy particle decay → very high energy scale ~ GUT scale Electroweak baryogenesis (Kuzmin, Rubakov and Shaposhnikov, 1985) uses sphaleron, electroweak phase transition → around electroweak scale, minimal extension of SM Affleck-Dine(AD) baryogenesis (Affleck and Dine, 1985) uses MSSM-flat directions → intermediate scale, very simple and efficient Several types of baryogenesis Introduction
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5 Unwanted? Why? - Large enery density → “over closing” universe - Long life time with large number density → disturbing successful BBN, etc. Properties * Primordial inflation can dilute sufficiently some heavy unwanted relics, - Small mass → thermal reproduction after reheating - Gravitationally suppressed weak coupling → late time decay or stable for example, monopoles Unwanted relics produced after inflation (gravitino, moduli problem) Introduction Gravitino problem (Khlopov and Linde, 1984; etc.)
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6 * Initial abundance * Observational constraint ? Large entropy release is required > ~ < ~ Moduli problem Introduction (Coughlan, et. al., 1983; etc.)
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7 Thermal Inflation due to thermal mass * Dilution factor: → Low scale → small number of e-folds inflation! Introduction * Thermal inflation (Lyth and Stewart, 1995)
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8 Coherent oscillation of moduli field Electroweak baryogenesis Thermal Inflation Flaton decay 1. GUT baryogenesis & leptogenesis 2. Affleck-Dine baryogenesis New model ? Incompatibility between thermal inflation and baryogenesis Motivation Too low temperature no baryogenesis mechanism can work
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9 -Working era: after thermal inflation to avoid dilution, before flaton decay to avoid too low energy scale - Efficiency: efficient from dilution by entropy release due to flaton decay => Proper base of new model = Affleck-Dine mechanism due to its efficiency The required features for new model Motivation Angular momentum = charge asymmetry * Affleck-Dine mechanism - Setting initial condition: Hubble terms due to SUSY-breaking effect of finite energy of early universe
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10 MSSM superpotential Our superpotential Neutrino mass term Flaton self interaction term -term with Superpotential, W Model (D. Jeong, K. Kadota, W. I. Park and E. D. Stewart, 2004)
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11 Simplification : C onsideration of just single generation Ansatz : Only and flaton have nonzero values Potential : where Model Ansatz & Potential
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12 Key assumptions - All fields are held at origin initially due to thermal effect - rolls away first, then : is unstable near the end of thermal inflation - -: is unstable at the end of thermal inflation Dynamics
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13 Dynamics 1a. rolls away 1b. Stabilizes 1c. Fixes initial phase of2a. rolls away 2b. becomes nonzero, → stabilizes dangerous directions 2c. Fixes phase of 3a. Brings back into origin 3b. Rotates the phase of 3c. Stabilizes
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14 Dynamics
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15 Way of resolution Problem due to - Stability of our vacuum : τ > 1/H τ = the time scale for quantum tunnelling to the minima 1/H = the age of our universe - Avoiding being trapped : dynamical settling down in our vacuum How about our model? - Stability of our vacuum : τ > 1/H in large enough parameter space (see “Kusenko, Langacker and Segre, 1996”) -Deeper non-MSSM minima do exist (see “Casas, Lleyda and Munoz, 1995”) Potential problems Dynamics ? MSSM Non-MSSM
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16 Gives negative mass squared to q Gives large mass to q All the fields settle down in our vacuum!!! deeper non-MSSM minimum exists with nonzero Give terms linear in where but - Avoiding being trapped: Dynamics
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17 Simulation results (homogeneous mode) Dynamics of AD-fieldLepton number asymmetry Dynamics
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18 Damping energy transfer from homogeneous modes to inhomogeneous modesPreheating: Thermal friction: decay when field passes near the origin Preserving lepton asymmetry Dynamics
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19 we expect { < ~ < ~ to Dynamics Estimation of baryon asymmetry
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20 Preliminary simulation result including preheating effect
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21 Moduli Domination Thermal Inflation Flaton Domination Radiation Domination held at origin rolls away ends thermal inflaton becomes nonzero stabilizes dangerous directions decays held at origin brought back into origin with phase rotation generation of L-asymmetry decays partial reheating EW symmetry restoration L-asymmetry → B-asymmetry B-asymmetry diluted but survives radiation domination BBN held at origin reaches its VEV oscillates Brief history of thermal inflation Summary & Conclusion rolls away
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22 Baryogenesis compatible with thermal inflation was proposed. Fairly minimal in the sense of particle physics theory. Unique in the context of gravity mediated SUSY breaking and thermal inflation. Flaton generated the -term and triggered the generation of lepton asymmetry. Complete analysis of the damping of field is required as future work. Our vacuum is unstable, but cosmological evolution leads to our vacuum. can be tested at future particle accelerators. Conclusions Summary & Conclusion
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