Standard model CP-violation and baryon asymmetry (II). Finite temperature

Abstract

We consider the scattering of quasi-particles off the boundary created during a first order electroweak phase transition. Spatial coherence is lost due to the quasi-quark damping rate, and we show that reflection on the boundary is suppressed, even at treelevel. Simply on CP considerations, we argue against electroweak baryogenesis in the Standard Model via the charge transport mechanism. A CP asymmetry is produced in the reflection properties of quarks and antiquarks hitting the phase boundary. An effect is present at order α 2 W in rate and a regular GIM behaviour is found, which can be expressed in terms of two unitarity triangles. A crucial role is played by the damping rate of quasi-particles in a hot plasma, which is a relevant scale together with M W and the temperature. The effect is many orders of magnitude below what observation requires.

The soft supersymmetry-breaking Lagrangian: theory and applications

“…Possible low energy coherent effect which evades the naive estimate of Eq. (7.5) is given in [610,611] which has been refuted for example by [612].…”

Light stop searches at the LHC in events with twobjets and missing energy

“…Furthermore, CP violation is needed in order to generate the baryon asymmetry * bornhaus@unm.edu † drees@th.physik.uni-bonn.de ‡ sgrab@scipp.ucsc.edu § jongsoo.kim@tu-dortmund.de [12]. The Standard Model (SM) CP violating Dirac phase is too small [13], whereas the MSSM contains additional CP-violating phases sufficient for EW baryogenesis [7]. However, new CP violating phases are strongly constrained by the non-observation of electric dipole moments ruling out large regions of the MSSM consistent with EW baryogenesis [6,8,9,14].…”

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“…6, but for a fixed value of the B − L breaking scale v R . One can see that successful leptogenesis is compatible with a "large" value of θ 13 (θ 13 …”

“…where we assume that the Y = +1 Higgs doublet in 10 1 does not acquire a vev, so that the mass relation M D = M u is left untouched 13 . The operators (54) will modify the reconstructed couplings f ij (hence the right-handed neutrino masses and couplings) by introducing a mismatch U m between the bases of left-handed charged lepton and down quark mass eigenstates:…”

“…The main outcome of these studies is that thermal leptogenesis can work with parameters consistent with the type I seesaw [11] interpretation of neutrino oscillation data. By contrast, standard electroweak baryogenesis [12] fails to produce the observed baryon asymmetry [13,14], and its supersymmetric version [15] is successful only in a small portion of the Minimal Supersymmetric Standard Model (MSSM) parameter space 2 .…”