arXiv subjects
Publications and source records attributed to T. Shishkina.
We present the matrix element of gamma gamma ->4l process with four charge particles in final state. The constructions are performed in frame of Standard Model of electroweak interaction using the helicity amplitude method . Every possible polarization state of initial and final particles are considered and analyzed.
We present the calculation of gamma gamma -> 2e+e- process cross section. The construction are perfomed using both helicity amplitude method and method of precision covariant calculation. The magnitude of cross section is obtained by the Monte-Carlo method of numerical integration. Different energies, polarization states and kinematics cuts are considered.
The main possibilities of investigation of leptons and bosons birth in interaction of polarized photons are considered. The usage of $γγ\to f \bar{f} [+γ]$ reactions for the luminosity measurement on linear photon collider is analyzed. The achievable precision of the luminosity measuring is considered and calculated. The first-order QED correction to $γγ\to l \bar{l}$ scattering is analyzed. Differential cross section of process $γγ\to 4l$ is calculated using the helicity amplitudes method as well as covariant method of precision calculations. All possible polarization states of interacting particles are investigated under different cuts of TESLA kinematics. For the detection of deviations from SM predictions at linear $γγ$ colliders with centre of mass energies running to $1 TeV$ the influence of three possible anomalous couplings on the cross sections of $W^+W^-$ productions has been investigated. The significant discrimination between various anomalous contributions is discovered. The main contribution of high order electroweak effects is considered.
Evaluation of anomalous couplings in the $γγ\to W^+W^-$ process needs to calculate the cross section $σ(W^+W^-)$ with a high precision. Therefore one has to consider the main contribution of high order effects. In this paper contributions of anomalous quartic boson interaction given by ${\cal L}_0$, ${\cal L}_c$, $\tilde{\cal L}_0$ are analyzed in high-energy region. Influence of high order effects is studed in dependences of $σ(W^+W^-)$ on anomalous constants and contour plots with statistical error $2δ$.
The production of several vector bosons in $γγ$-interactions is the best place to search directly for any anomalous behavior of triple and quartic couplings. A few anomalous quartic boson operators are considered in the paper. A high precision of anomalous effects can be achieved by calculation of the lowest order electroweak corrections: one-loop corrections, real photon and $Z$-boson emission.
The process gamma gamma -> l+ l- is highly suppressed when the total angular momentum of the two colliding photons is zero so that it cannot be used for luminosity determination. This configuration, however is needed for Higgs production at a photon collider. It will be shown that the process gamma gamma -> l+ l- gamma can be used in this case to measure the luminosity of a collider with a precision that is good enough not to limit the error on the partial decay width Gamma(H -> gamma gamma).
The WW production in gamma-gamma scattering is considered in the Standard Model. The main contribution to radiative effects for the process gamma-gamma->WW has been calculating and analyzing. It is found the latter is considerable at high energies and greatly contributes to the differential cross section $dσ$ at various polarizations of initial photons and final bosons. Monte-Carlo generator built based on TESLA kinematics.