New Mechanism For Baryogenesis Research Articles

Direct baryogenesis in the broken phase

We show a new mechanism for baryogenesis where the reheating temperature can be smaller than the electroweak scale. The baryon number symmetry is violated by a dimension nine operator which conserves a baryon parity. A high energy quark from the decay of a heavy particle, e.g. inflaton, modulus or gravitino, undergoes flavor oscillation, and is thermalized due to the scatterings with the ambient thermal plasma. We point out that the baryon asymmetry of our universe can be generated due to the scatterings via the baryon number violating operator. Our scenario can be tested in neutron-antineutron oscillation experiments as well as other terrestrial experiments.

Early Cosmological Period of QCD Confinement.

If the strong coupling is promoted to a dynamical field-dependent quantity, it is possible that the strong force looked very different in the early Universe. We consider a scenario in which the dynamics is such that QCD confines at high temperatures with a large dynamical scale, relaxing back to ∼1 GeV before big bang nucleosynthesis. We discuss the cosmological implications and explore potential applications, including fleshing out a new mechanism for baryogenesis which opens up if QCD confines before the electroweak phase transition of the standard model.

Baryogenesis via mesino oscillations

We propose a new mechanism for baryogenesis at the 1-200 MeV scale. Enhancement of CP violation takes place via interference between oscillations and decays of mesinos--bound states of a scalar quark and antiquark and their CP conjugates. We present the mechanism in a simplified model with four new fundamental particles, with masses between 300 GeV and 10 TeV, and show that some of the experimentally allowed parameter space can give the observed baryon-to-entropy ratio.

Axino LSP baryogenesis and dark matter

We discuss a new mechanism for baryogenesis, in which the baryon asymmetry is generated by the lightest supersymmetric particle (LSP) decay via baryonic R-parity-violating interactions. As a specific example, we use a supersymmetric axion model with an axino LSP. This scenario predicts large R-parity violation for the stop, and an upper limit on the squark masses between 15 and 130 TeV, for different choices of the Peccei-Quinn scale and the soft Xt terms. We discuss the implications for the nature of dark matter in light of the axino baryogenesis mechanism, and find that both the axion and a metastable gravitino can provide the correct dark matter density. In the axion dark matter scenario, the initial misalignment angle is restricted to be \U0001d4aa(1). On the other hand, the reheating temperature is linked to the PQ scale and should be higher than 104–105 GeV in the gravitino dark matter scenario.

Baryogenesis, dark matter and the pentagon

We present a new mechanism for baryogenesis, which links the baryon asymmetry of the universe to the dark matter density. The mechanism arises naturally in the Pentagon model of TeV scale physics. In that context, it forces a re-evaluation of some of the assumptions of the model, and we detail the changes that are required in order to fit observations.

A new mechanism for baryogenesis living through electroweak era

We present a new mechanism for baryogenesis by introducing a heavy vector-like SU(2)W singlet quark(s) with Qem=23 quark U or Qem=−13 quark D. The lifetime of the heavy quark is assumed to be in the range 2×10−11s<τ<1s. Being SU(2)W singlet, it survives the electroweak phase transition era. It mixes with SU(2)W doublet quarks with tiny mixing angles to satisfy the FCNC constraints, where a simple Z2 symmetry is suggested for realizing this scheme. The heavy quark asymmetry is generated in analogy with the old GUT scenario.

Neutrinos as the messengers ofCPTviolation

CPT violation has the potential to explain all three existing neutrino anomalies without enlarging the neutrino sector. CPT violation in the Dirac mass terms of the three neutrino flavors preserves Lorentz invariance, but generates independent masses for neutrinos and antineutrinos. This specific signature is strongly motivated by braneworld scenarios with extra dimensions, where neutrinos are the natural messengers for Standard Model physics of CPT violation in the bulk. A simple model of maximal CPT violation is sufficient to explain the exisiting neutrino data quite neatly, while making dramatic predictions for the upcoming KamLAND and MiniBooNE experiments. Furthermore we obtain a promising new mechanism for baryogenesis.

A new mechanism for baryogenesis in low energy supersymmetry breaking models

A generic prediction of models where supersymmetry is broken at scales within a few orders of magnitude of the weak scale and is fed down to the observable sector by gauge interactions is the existence of superconducting cosmic strings which carry baryon number. In this paper we propose a novel mechanism for the generation of the baryon asymmetry which takes place at temperatures much lower than the weak scale. Superconducting strings act like “bags” containing the baryon charge and protect it from sphaleron wash-out throughout the evolution of the Universe, until baryon number violating processes become harmless. The superconducting strings are out of equilibrium configurations which admit baryon number violating processes such that all of the Sakharov criteria for baryogenesis are satisfied. Our mechanism is efficient even if the electroweak phase transition in the MSSM is of second order and therefore does not impose any upper bound on the mass of the Higgs boson.

Supersymmetric (s)neutrino-mass induced baryogenesis

We propose a new mechanism for baryogenesis in supersymmetric extensions of the standard model, that does no depend on (super)GUT interactions. It occurs by the non-perturbative electroweak reprocessing of a lepton asymmetry is generated by the effects of lepton number violating induced operators, arising from “see-saw” (s)neutrino masses, which act on scalar condensate oscillations along flat directions of the supersymmetric standard model.

Why the baryon asymmetry of the universe is ∼ 10 −10

We elaborate a new mechanism for baryogenesis in extended versions of the electroweak theory. We show that a baryon asymmetry of the universe is an inevitable consequence of these theories, provided there is CP violation in the Higgs sector and the cosmological phase transition in which the SU (2) group is broken in first order. The net asymmetry is generally of the order of α w 4 times the magnitude of CP violation divided by the number of particle degrees of freedom relevant at this energy, and is close to the observed value.

A new mechanism for baryogenesis

A new mechanism for baryogenesis is proposed. It is argued that, after inflation, the scalar quarks and leptons of a supersymmetric GUT may have large expectation values. The subsequent evolution of such a system is shown to generate a significant baryon density. For typical values of the parameters, nB/nγ may be as large as 103.