Generalization of a theorem by Schroer and Jost

It is proved that a hermitian scalar local field satisfying the Wightman axioms is a free one if a singlen-point Wightman function (n 1,n 3) satisfies the homogeneous Klein-Gordon equation at least in one variable.     

Baryon asymmetry of the universe and the electroweak phase transition

The present baryon asymmetry of the universe has finally been determined at the finite temperature electroweak phase transition. The strength of this transition plays a crucial role. The effective action is presented to higher orders, including wave function correction factors and the fullg ⁴, λ² effective potential. An upper bound for the Higgs massm _H～70 GeV is concluded for the reliability of the perturbative approach. The finite temperature electroweak, phase transition is studied on the lattice and the most important results of Monte-Carlo simulations are collected.     

Electroweak phase transition in the minimal supersymmetric standard model: 4-dimensional lattice simulations

Lattice results show no standard model (SM) electroweak phase transition (EWPT) for Higgs masses approximately 72 GeV, which is below the present experimental limit. Perturbation theory and 3-dimensional simulations indicate an EWPT in the minimal supersymmetric SM (MSSM) that is strong enough for baryogenesis up to m(h) approximately 105 GeV. In this Letter we present the results of our large scale 4-dimensional MSSM EWPT simulations. We carried out infinite volume and continuum limits and found a transition whose strength agrees well with perturbation theory, allowing MSSM electroweak baryogenesis at least up to m(h) = 103+/-4 GeV. We determined the properties of the bubble wall.     

Hadron clusters with quark core and multiplicity distributions

Multiplicity distributions of ground state hadrons (pseudoscalar and vector meson nonet and baryon octet and decuplet) are investigated in a model of hadron clusters based of subsequent hadron emission by quarks. The effects of resonance decay for the observed (stable) hadron multiplicities are also considered. Average numbers of different hadrons are calculated as a function of the number of charged pions. The results are compared with available data and a good overall agreement is found.     

The number of neutral pions and fireballs with quark quantum numbers

The prediction of fireball models that for fixed total pion number the neutral versus charged pion distribution is binomial is confronted with experiment. The agreement is very good with available data. This restricts coupling ratios in the statistical model for fireball decay to coincide with those of a simple quark model.     

Statistical chain decay of fireballs with quantum numbers

The effects of internal quantum number consevation are considered in the statistical chain decay of fireballs. A simple model containing I = 1, G = ?1, S = 0 mesons (ground state and excited pions) and $\text{I =}\text{1}\text{2}\text{, S = 0}$ baryons (ground state and excited nucleons) is investigated in detail: inclusive distributions, multiplicity distributions and semi-inclusive distributions are determined. The methods are completely general and can be used in more general models with any set of states. As examples, a model with ? and π mesons, and nucleons and another one with π and K mesons, and N and Λ baryons are considered.     

Mirror fermion production inep collisions

The phenomenology of mirror fermions is studied in a model with three heavy mirror fermion families. The tree unitarity bounds on the mirror masses are determined. The production cross-sections and decay characteristics of mirror fermions are calculated in high energy electron-proton collisions. For mirror mixing angles of the order of the present upper limits mirror fermion production at HERA ( \(\sqrt s = 314 GeV\) ) is observable up to masses near 200 GeV. For a possible HERA upgrade ( \(\sqrt s = 566 GeV\) ) this limit goes up to about 350 GeV and anep collider in the LEP tunnel ( \(\sqrt s = 1.4 TeV\) ) could cover the range below 500 GeV.