We investigate pair production of selectrons in electron-electron-scattering with subsequent decay into an electron and the LSP including ISR and beamstrahlung. This process can be used at a linear collider to measure the selectron masses and the gaugino mass parameter M_1 very precisely.
The cross section for muon pair productions by electrons scattering over photons, $sigma_{MPP}$, is calculated analytically in the leading order. It is pointed out that for the center-of-mass energy range, $s geq 5 m^{2}_{mu}$, the cross section for
$sigma_{MPP}$ is less than $1 mu $b. The differential energy spectrum for either of the resulting muons is given for the purpose of high-energy neutrino astronomy. An implication of our result for a recent suggestion concerning the high-energy cosmic neutrino generation through this muon pair is discussed.
The process of two pion production in the electron-polarized proton scattering is investigated. In the Weizsacker-Williams approximation the differential spectral distributions and the spin-momentum correlations are considered. The spin correlation e
ffects caused by $rho$-meson widths are estimated to be of an order of several per cent. Both channels of the $pi^+pi^-$ and $pi^+pi^0$ creation are considered. The effects of intermediate excited baryons are not considered. The spectral distributions on pion energy fractions in polarized and unpolarized cases are presented analytically and numerically.
We investigate selectron pair production and decay in e-e- scattering and e+e- annihilation with polarized beams taking into account neutralino mixing as well as ISR and beamstrahlung corrections. One of the main advantages of having both modes at di
sposal is their complementarity concerning the threshold behaviour of selectron pair production. In e-e- the cross sections at threshold for seleectron_R selectron_R and selectron_L selectron_L rise proportional to the momentum of the selectron and in e+ e- that for selectron_R selectron_L. Measurements at threshold with polarized beams can be used to determine the selectron masses precisely. Moreover we discuss how polarized electron and positron beams can be used to establish directly the weak quantum numbers of the selectrons. We also use selectron pair production to determine the gaugino mass parameter M_1. This is of particular interest for scenarios with non-universal gaugino masses at a high scale resulting in |M_1| << |M_2| at the electroweak scale. Moreover, we consider also the case of a non-vanishing selectron mixing and demonstrate that it leads to a significant change in the phenomenology of selectrons.
In high energy electron-ion colliders, a new way to probe nucleon structure becomes available through diffractive reactions, where the incident particle produces a very energetic almost forward particle. QCD describes these reactions as due to the ex
change of a Pomeron which may be perturbatively described as a dressed two-gluon state, provided a hard scale allows the factorization of the amplitude in terms of two impact factors convoluted with a Pomeron propagator. We consider here a process where such a description allows to access hadronic structure in terms of the generalized parton distributions, namely the electroproduction of a forward $rho$ meson and a timelike deeply virtual photon, separated by a large rapidity gap. We explore the dependence of the cross section on the kinematic variables and study the dependence on the non-perturbative inputs (generalized parton distributions, distribution amplitude). Our leading order studies show the cross section is mainly sensitive to the GPD model input, but the small size of the cross sections could prohibit straightforward analysis of this process at planned facilities.
Process of muon (pion) pair production with small invariant mass in the electron-positron high-energy annihilation, accompanied by emission of hard photon at large angles, is considered. We find that the Dell-Yan picture for differential cross sectio
n is valid in the charge-even experimental set-up. Radiative corrections both for electron block and for final state block are taken into account.