Related papers: epsilon'/eps in the Standard Model
Quantities like the fine structure constant at the pole of the Z boson and the anomalous magnetic moment of the muon are of profound importance for testing the Standard Model of elementary particle physics. Because these quantities are…
A model independent analysis has been performed on the LEP and SLD data on Z decays. Using only very weak theoretical assumptions, the effective vector and axial-vector couplings of leptons, c quarks and b quarks have been extracted.…
Previous numerical studies have revealed the existence of embedded solitons (ESs) in a class of multi-wave systems with quadratic nonlinearity, families of which seem to emerge from a critical point in the parameter space, where the zero…
Recent calculations have significantly decreased the scheme and residual scale dependence of basic radiative corrections of the Standard Electroweak Model. This leads to a theoretically accurate prediction of the W-boson mass M(W), as well…
We calculate the mass of the Higgs boson in the Standard Model in terms of the underlying Lagrangian parameters at complete 2-loop order with leading 3-loop corrections. A computer program implementing the results is provided. The program…
We discuss some phenomenological aspects of an $E_6$ inspired supersymmetric standard model with an extra $U(1)_{N}$ gauge symmetry under which right-handed neutrinos have zero charge, allowing a conventional see-saw mechanism. The $\mu$…
The Standard Model fit prefers values of the Higgs boson mass that are below the 114 GeV direct lower limit from LEP II. The discrepancy is acute if the 3.2 sigma disagreement for the effective weak interaction mixing angle from the two…
This contribution reviews the latest results of the perturbative calculations of heavy-Higgs amplitudes. A comparison of perturbative results with nonperturbative lattice calculations is made, and the theoretical uncertainties of the lower…
The K to pi pi system is analyzed in the chiral limit and at NLO in 1/N_c. The Delta I = 1/2 rule is reproduced and we obtain a large value for epsilon' / epsilon.
The Electroweak sector of the Standard Model is reviewed and best fits are presented for its free parameters based on currently available experimental tests. The Standard Model remains an excellent descriptions of the available experimental…
Light quark masses are important fundamental parameters of the Standard Model. The decays psi'-->J/psi pi^0 (eta) were widely used in determining the light quark mass ratio m_u/m_d. However, there is a large discrepancy between the…
The estimates of overall strange quark production in high energy e+e-, pp and ppbar collisions by using the statistical-thermal model of hadronisation are presented and compared with previous works. The parametrization of strangeness…
The paper introduces a new estimation method for the standard linear regression model. The procedure is not driven by the optimisation of any objective function rather, it is a simple weighted average of slopes from observation pairs. The…
The present status of precision electroweak data is reviewed. These data include measurements of e+e- -> f+fbar, taken at the Z resonance at LEP, which are used to determine the mass and width of the Z boson. In addition, measurements have…
An updated global analysis within the Standard Model (SM) of all relevant electroweak precision and Higgs boson search data is presented with special emphasis on the implications for the Higgs boson mass, M_H. Included are, in particular,…
The stability of the Standard Model is determined by the true minimum of the effective Higgs potential. We show that the potential at its minimum when computed by the traditional method is strongly dependent on the gauge parameter. It…
Anomaly free $U(1)$ extensions of the standard model (SM) predict a new neutral gauge boson $Z'$. When the $Z'$ obtains its mass from the spontaneous breaking of the new $U(1)$ symmetry by a new complex scalar field, the model also predicts…
The $K\to\pi\pi$ system is analyzed in the chiral limit within the Standard Model. We discuss how to connect the short-distance running in the $|\Delta S|=1$ case to the matrix-elements calculated in a low-energy approximation in a…
High statistics Standard Model processes like fermion- and photon-pair production in e+e- collisions are studied at centre-of-mass energies up to 209 GeV. No significant deviation from the Standard Model is observed, leading to strong…
The CP violation parameter $Re(\epsilon'/\epsilon)$ has previously been calculated in the standard model and the result depends on the top quark mass in an exciting way. We consider how the result is modified in two specific extensions of…