Related papers: Results for all reactions e+ e- -> 4f, 4f + gamma …
Fermion compositeness, and other types of new physics that can be described by the exchange of very massive particles, can manifest themselves as the result of an effective four-fermion contact interaction. In the case of the processes…
Assuming that the leptons and quarks other than top are massless at tree level, we show that their masses may be induced by loops involving the top quark. As a result, the generic features of the fermion mass spectrum arise from…
A fourth generation of Standard Model (SM) fermions is usually considered unlikely due to constraints from direct searches, electroweak precision measurements, and perturbative unitarity. We show that fermion mass textures consistent with…
We consider fermions on an extra dimensional interval. We find the boundary conditions at the ends of the interval that are consistent with the variational principle, and explain which ones arise in various physical circumstances. We apply…
We present the NGAMMA Monte Carlo event generator for QED processes of $e^+e^-$ annihilation into a multiphoton final state, $e^+e^-\to N\gamma (N \ge 2)$. These processes are an important source of background in the study of $e^+e^-\to…
The structure of the double-pole approximation for the O(alpha) corrections to e^+e^- -> WW -> 4 fermions is described, and some results are presented. Moreover, results on full tree-level predictions for $e^+e^- -> WW -> 4 fermions + gamma…
Data from the Large Electron Positron collider (LEP) at CERN on hadron production in gamma-gamma interactions exceed the predictions of the standard model by an order of magnitude at the highest observed transverse momenta in three…
We present an extension of the Standard Model (SM) without supersymmetry, which we use to calculate order of magnitude values for the elements of the mass matrices in the SM. In our model we can fit the 9 quark and lepton masses and 3…
The complete electroweak O(alpha) corrections have been calculated for the charged-current four-fermion production processes e+e- --> nu_tau tau+ mu- anti-nu_mu, u anti-d mu- anti-nu_mu, and u anti-d s anti-c. Here, technical details of…
We present predictions for b-quark production in photoprodcution and compare with experimental data from HERA. Our theoretical predictions are obtained at next-to-leading-order in the general-mass variable-flavor-number scheme, an approach…
The O(alpha) electroweak radiative corrections to gamma gamma --> WW --> 4f within the electroweak Standard Model are calculated in double-pole approximation (DPA). Virtual corrections are treated in DPA, leading to a classification into…
The reaction $\gamma + p\to \eta^\prime + p$ is investigated in the quark model approach. The quark model predicts that the off-shell contributions from the resonance $S_{11}(1535)$ dominate the $\etap$ production in the threshold region.…
After 10 years of steadily increasing the experimental precision at LEP/SLC, there is a strong demand on an update of existing programs for fermion pair production. We present a rederivation of the O(alpha) Bremsstrahlung corrections to…
We study the non-factorizable corrections to W-pair-mediated four-fermion production in ee annihilation in double-pole approximation. We show how these corrections can be combined with the known corrections to the production and the decay…
The framed standard model (FSM) suggested earlier, which incorporates the Higgs field and 3 fermion generations as part of the framed gauge theory structure, is here developed further to show that it gives both quarks and leptons…
The cross sections for the reaction $\gamma\gamma\rightarrow 4\ell$ in proton--proton collisions are calculated at the LHC energies. We show that the purely electroweak process $\gamma\gamma\rightarrow 4\ell$ can be studied at the LHC and…
The reaction mechanism of nucleus-nucleus collisions at projectile energies around the Fermi energy is investigated with emphasis on the production of fragmentation-like residues. The results of simulations are compared to experimental mass…
Recent theoretical studies of the e+ e- --> K + K- gamma process are described. Three main reaction mechanisms are considered: the initial state radiation, the final state radiation and the strong interaction between the outgoing K+ K-…
The exclusive production of baryon antibaryon pairs in the collisions of two quasi-real photons have been studied in different experiments at e+e- colliders. Results are presented for the processes gamma gamma to proton antiproton and gamma…
We consider the generation of fermion masses in an emergent model of electroweak symmetry breaking with composite $W,Z$ gauge bosons. A universal bulk fermion profile in a warped extra dimension is used for all fermion flavors. Electroweak…