Particle PhysicsParticle Physicsand Cosmologyand Cosmology

Phase transitionsPhase transitions

baryogenesis during baryogenesis during electroweak phase electroweak phase

transition ?transition ?

Sakharov’s conditions forSakharov’s conditions forbaryogenesis during baryogenesis during electroweak phase electroweak phase

transitiontransition

1)1) baryon number violation interactions ☺baryon number violation interactions ☺

2)2) charge conjugation violating charge conjugation violating interactions ☺interactions ☺

3)3) CP – violating interactions ☺CP – violating interactions ☺

4)4) non – equilibrium process ☺non – equilibrium process ☺

baryogenesis during baryogenesis during electroweak phase electroweak phase

transition ?transition ? strongly first order electroweak strongly first order electroweak

phase transition can generate baryon phase transition can generate baryon asymmetry if CP violation is asymmetry if CP violation is sufficiently strong sufficiently strong

no efficient baryogenesis for weak no efficient baryogenesis for weak first order phase transition, second first order phase transition, second order phase transition or crossoverorder phase transition or crossover

presumably too little CP violation in presumably too little CP violation in SM ( not definitely settled )SM ( not definitely settled )

electroweak phase electroweak phase transitiontransition

order of phase transitionorder of phase transition

temperature dependent temperature dependent effective potentialeffective potential

T = 0T = 0

high high temperaturetemperature

expansionexpansion

next to leading order in next to leading order in high temperature high temperature

expansionexpansion

first order cosmological first order cosmological phase transitionsphase transitions

chaos in the Universechaos in the Universe

relics from cosmological relics from cosmological first order phase transitions first order phase transitions

??

electroweak crossoverelectroweak crossover

critical mass of the Higgs critical mass of the Higgs scalar for the onset of scalar for the onset of

crossovercrossover

electroweak “phase electroweak “phase transition “transition “

in standard model is in standard model is crossover !crossover !

perhaps strong first order transition in perhaps strong first order transition in supersymmetric extensions of standard model supersymmetric extensions of standard model

standard model of particle standard model of particle physics and cosmologyphysics and cosmology

no candidate for dark matterno candidate for dark matter no baryon asymmetryno baryon asymmetry no massive neutrinosno massive neutrinos

standard model of particle standard model of particle physics and cosmologyphysics and cosmology

prediction :prediction :

present Universe consists ofpresent Universe consists of

photons and photons and

massless neutrinosmassless neutrinos