Spontaneous generation of torsion coupling of electroweak massive gauge bosons

We derive the coupling to torsion of massive electroweak vector bosons generated by the Higgs mechanism.     

Some phenomenological predictions of charged Higgs bosons in electroweak interactions

Some phenomenological consequences of an extended Salam-Weinberg model are studied. In particular, the existence, or absence, ofe?μ asymmetry in beam-dump experiments is analyzed and an increase in same sign dilepton cross sections is shown to exist due to the contribution of charged Higgs-mediated diagrams. The model is shown to be compatible with experimental results for other processes.     

Spin asymmetries in large-pT production of gauge bosons based on quantum chromodynamics and electroweak gauge model

We make predictions for spin asymmetries in the production of gauge bosons, such as Z⁰, Wsu± and γ, at large p_T from the collision of longitudinally polarized hadrons using QCD perturbation theory and the electroweak gauge model in the framework of a hard scattering model. Asymmetries typically at the 20% and 4% level are predicted for the weak bosons and photon, respectively. Experimental tests should be possible in the near future, e.g., at Fermilab, ISABELLE and colliding SPS.     

Uniqueness of the standard electroweak gauge model

It is proved that the standard SU(2) × U(1) electroweak gauge model is unique against any extension if the effective low-energy neutral-current interaction is to be precisely of the form $\text{(4G}{}_{\mathrm{F}}\text{/}\text{2}\text{) (j}{}_{\mathrm{\mu }}{}^{\mathrm{(3)}}\text{?}\text{sin}{}^2\text{θ}{}_{\mathrm{<mtext>W</mtext>}}\text{j}{}_{\mathrm{\mu }}{}^{\mathrm{<mtext>em</mtext>}}\text{)}{}^2$naturally.     

The electroweak standard model in the axial gauge

We derive the Feynman rules of the standard model in the axial gauge. After this we prove that the fields and do not correspond to physical particles. As a consequence, these fields cannot appear as incoming or outgoing lines in Feynman graphs. We then calculate the contribution of these fields in the case of a particular decay mode of the top quark.Received: 28 January 2004, Revised: 12 February 2004, Published online: 8 April 2004     

Fermion condensate model of electroweak interactions

A new dynamical symmetry breaking model of electroweak interactions is proposed based on interacting fermions. Two fermions of different SU_L(2) representations form a symmetry breaking condensate and generate the lepton and quark masses. The weak gauge bosons obtain their usual standard model masses from a gauge-invariant Lagrangian of a doublet scalar field composed of the new fermion fields. The new fermion fields become massive by condensation. It is shown that the new charged fermions are produced at the next linear colliders in large number. The model is a low-energy one, which cannot be renormalized perturbatively. For the parameters of the model, unitarity constraints are presented.     

Electroweak interactions at an infinite sublayer quark level. IV. Composite model of electron,neutrino, and gauge bosons

We assume that the electron (e ^–), neutrino (v _e), and gauge bosons (W ^±,Z ⁰) are composed of only two kinds of particles, an ultimate particleu at an infinite sublayer quark level and a chargeless fermiont, such thate ^–=(u ^cp u ^cp l),V _e =(u u ^cp l,W ⁺=(u u ),W ^–=(u ^cp u ^cp andZ ⁰=(u u ^cp . It is then shown thatCP is violated in weak interactions associated with these electron, neutrino, and gauge bosons.     

QED bremsstrahlung in decays of electroweak bosons

Isolated lepton momenta, in particular their directions are the most precisely measured quantities in pp collisions at LHC. This offers opportunities for multitude of precision measurements. It is of practical importance to verify if precision measurements with leptons in the final state require all theoretical effects evaluated simultaneously or if QED bremsstrahlung in the final state can be separated without unwanted precision loss. Results for final-state bremsstrahlung in the decays of narrow resonances are obtained from the Feynman rules of QED in an unambiguous way and can be controlled with a very high precision. Also for resonances of non-negligible width, if calculations are appropriately performed, such separation from the remaining electroweak effects can be expected. Our paper is devoted to validation that final-state QED bremsstrahlung can indeed be separated from the rest of QCD and electroweak effects, in the production and decay of Z and W bosons, and to estimation of the resulting systematic error. The quantitative discussion is based on Monte Carlo programs PHOTOS and SANC, as well as on KKMC which is used for benchmark results. We show that for a large class of W and Z boson observables as used at LHC, the theoretical error on photonic bremsstrahlung is 0.1 or 0.2 %, depending on the program options used. An overall theoretical error on the QED final-state radiation, i.e. taking into account missing corrections due to pair emission and interference with initial state radiation is estimated respectively at 0.2 % or 0.3 % again depending on the program option used.     

Production of electroweak bosons at colliders

The collider experiments at the Tevatron and LHC are accumulating samples of electroweak bosons of unprecedented size. These huge samples can be used to observe rare processes, such as diboson production which have the potential to show enhancements due to new physics. Alternatively, the great statistical power of the samples allows for detailed studies of electroweak production mechanisms and correspondingly QCD and the proton structure.     

Pseudo-Finsleroid standard model analysis of electroweak interactions

A standard model Lagrangian is constructed making the pseudo-Finsleroid generalization of the Yang-Mills field equation by the conformal method. The Higgs field potential is suggested that ensures generation of particle masses caused by the spontaneous symmetry breaking. After transition to the conformal coordinates, the expressions obtained assume the standard form that in many cases allows the results of pseudo-Euclidean theory to be used in calculations of the Feynman diagrams. __________ Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 4, pp. 44–51, April, 2006.     

Limiting case of modified electroweak model for contracted gauge group

The modification of the Electroweak Model with 3-dimensional spherical geometry in the matter fields space is suggested. The Lagrangian of this model is given by the sum of the free (without any potential term) matter fields Lagrangian and the standard gauge fields Lagrangian. The vector boson masses are generated by transformation of this Lagrangian from Cartesian coordinates to coordinates on the sphere S ³. The limiting case of the bosonic part of the modified model, which corresponds to the contracted gauge group SU(2; j) × U(1) is discussed. Within framework of the limit model Z boson and electromagnetic fields can be regarded as external ones with respect to W-boson fields in the sence that W-boson fields do not effect on these external fields. The masses of all particles of the Electroweak Model remain the same, but field interactions in contracted model are more simple as compared with the standard Electroweak Model.