180 likes | 199 Views
Baryogenesis: The quest for the origin of matter. 1 . hep-ph/0505103. Tomislav Prokopec (ITP&Spinoza Institute, Utrecht U.). hep-ph/0410135, Nucl. Phys. B716 (2005). Collaborators :. Thomas Konstandin (ITP, Heidelberg). Michael G. Schmidt (ITP, Heidelberg).
E N D
Baryogenesis: The quest for the origin of matter 1 hep-ph/0505103 TomislavProkopec (ITP&Spinoza Institute, Utrecht U.) hep-ph/0410135, Nucl. Phys. B716 (2005) Collaborators: Thomas Konstandin(ITP, Heidelberg) Michael G. Schmidt(ITP, Heidelberg) Marcos Seco (ITP, Heidelberg) Durham , July 22 2005
2 Observed matter-animatter asymmetry The ratio of baryon and photon number densities: -nucleosynthesis constraint, cmbr measurements (WMAP)
3 Baryonic matterand cmbr baryons: increase compression (odd) peaks, decrease rarefaction peaks
4 Strong first order transition in MSSM allowed “triangle” for MSSM: Carena, Quiros, Seco, Wagner, 2000 weak transition : T strong transition: T R-stop mass color breaking phase Higgs mass
5 Electroweak baryogenesis at a strong 1st order transition Cohen,Kaplan,Nelson 1991 diffusion: ink in water 8 expanding bubbles of higgs phase 8 CP violation on bubble walls 8 B violation in symmetric phase
6 Supersymmetry and MSSM ●To each particle of the Standard Model one associates a particle with a different statistic: charginos & neutralinos NB: In contrast to SM, MSSM has 2 complex Higgs doublet fields
7 Semiclassical force for charginos Joyce, Prokopec, Turok, 1994 LAGRANGIAN Kainulainen, Prokopec, Schmidt, Weinstock 2001 Fs ● The presence of a propagating bubble wall (Higgs condensate) induces charginoflavour oscillations (1st order in gradients), analogous to neutrino flavour oscillations, and semiclassical force (2nd order in gradients)
8 Semiclassical force mechanism LAGRANGIAN Kainulainen, Prokopec, Schmidt, Weinstock, 2001, 2002 DIRAC EQUATION FORWIGHTMAN/WIGNER FUNCTION: Conserved spin (σ, ρ are Pauli matrices) Constraint equation
9 Semiclassical force mechanism:dispersion relation DISPERSION RELATION (implied by the constraint equation) 1st order shift NB: CP-violating shift at first order in gradients Consequence: a second order semiclassical force in kinetic equation, which source CP-violating currents needed for baryogenesis Kinetic equation: semiclassical force NB: CP-violating semiclassical force dominates baryogenesis for one fermion scattering off the propagating bubble; if there are several fermion flavours (e.g. Charginos, neutralinos), there is a first order effect (Huet, Nelson, ‘95)
10 Flavor oscillations of charginos LAGRANGIAN Konstandin, Prokopec, Schmidt, Seco, 2004 & 2005 Kinetic equations for chiral densities (to 1st order in gradients): NOTE: sign of commutator! Definition of CP operation (suitable for mixing fermions): NOTE: additional transposition!
11 Flavor oscillations and baryogenesis Solving kinetic equations (Green function method): -first order sources: Resulting CP violating currents: (MINUS current) -2nd order axial vector current (PLUS current)
12 Charginos mediated baryogenesis ●Charginosdecay into quarks & leptons via weak strength interactions: ● Sphalerons bias production of net baryon number, which diffuses into broken phase We solve the relevant diffusion equations. We use the system of equations initially proposed by Huet and Nelson 1995, and refined in the work of Carena, Moreno, Quiros, Seco, Wagner 2000; Balazs et al 2004).
CHARGINO BARYOGENESIS INMSSM (1) • 13 Konstandin, Prokopec, Schmidt, hep-ph/0505103 (2005) Baryon production from different sources: b=nb/n chargino oscillations: Sa,Sb,Sc semiclassical force: Sd Damping =0.25wT Damping =wT
CHARGINO BARYOGENESIS INMSSM (2) • 14 Baryon production b=nb/n as a function of mc & mA
CHARGINO BARYOGENESIS INMSSM (3) • 15 Baryon productionb=nb/n as a function ofc,tan& mA=150GeV
ELECTRIC DIPOLE MOMENT FROM MSSM • 16 The current measurement bound of the electron electric dipole moment (EDM) Regan et al, Phys. Rev. Lett. 88:071805, 2002 The standard model (MSM) value for eEDM (4 loop) Pospelov, Khriplovich, Sov.J.Nucl.Phys.53:638-640,1991, Yad.Fiz.53:1030-1033,1991 The standard model (MSM) value for neutron EDM (2 loop penguin) The MSSM 2 loop Higgs contribution for electron EDM
CHARGINO BARYOGENESIS INMSSM (4) • 17 black regions mean Baryon asymmetry from charginos with maximum CP violation assumed The current measurements of the electron electric dipole moment Regan et al, Phys. Rev. Lett. 88:071805, 2002 constrain the CP violating phase to be < 0.1, implying that charginos cannot produce enough baryons to explain the BAU (unless there are fortuitious cancellations of the MSSM contributions to the EDM.
18 CONCLUSIONS When the current EDM bounds are taken account of, we find that the charginos of the MSSM (higgsinos decay into tops, which bias sphalerons) cannot generate a successful electroweak scale baryogenesis. Several improvements w.r.t. earlier work (basis independent treatment; the amplitude of sources in diffusion equation; the role of damping and resummed solution of kinetic equation) have had as a net effect a reduction in baryon production. The next generation of colliders (LHC, ILC) and the new generation of EDM measurementswill provide a decisive probe of the electroweak scale baryogenesis