Polarization observables in lepton-deuteron elastic scattering including the lepton mass

Expressions for the unpolarized differential cross section and for various polarization observables in the lepton-deuteron elastic scattering, $\ell+D\to \ell+D$, $\ell=e$, $\mu$, $\tau$, have been obtained in one-photon-exchange approximation, taking into account the lepton mass. Polarization effects have been investigated for the case of a polarized lepton beam and polarized deuteron target which can have vector or tensor polarization. Numerical estimations of the lepton mass effects have been done for the unpolarized differential cross section and for some polarization observables and applied to the case of low energy muon deuteron elastic scattering.Comment: 29 pages, 6 figur

Asymptotic behavior of nucleon electromagnetic form factors in time-like region

We study the asymptotic behavior of the ratio of Pauli and Dirac electromagnetic nucleon form factors, $F_2/F_1$, in time-like region for different parametrizations built for the space-like region. We investigate how fast the ratio $F_2/F_1$ approaches the asymptotic limits according to the Phragm\`en-Lindel\"of theorem. We show that the QCD-inspired logarithmic behavior of this ratio results in very far asymptotics, experimentally unachievable. This is also confirmed by the normal component of the nucleon polarization, $P_y$, in $e^++e^-\to N+\bar{N}$ (in collisions of unpolarized leptons), which is a very interesting observable, with respect to this theorem. Finally we observe that the 1/Q parametrization of $F_2/F_1$ contradicts this theorem.Comment: 9 pages, 1 figur

Manifestation of heavy 3/2-spin lepton in large-angle e+e−→γγe^+e^-\rightarrow \gamma\gamma reaction at high energies

Manifestation of the heavy 3/2-spin lepton $(h^\pm)$, as possible virtual intermediate state in Feynmann diagrams, have been searched in the $e^+\,e^-\to \gamma\,\gamma$ reaction at high energies and large photon angles. The spin-vector field $\Psi_\alpha$ of the 3/2-lepton is described by the Rarita-Schwinger one and phenomenological Lagrangian of $h^\pm\, e^\pm \, \gamma$-interaction is chosen similarly to interaction of $\Delta$ isobar with nucleon and $\gamma$ quant. It is described by two constants with dimension $[M^{-1}]$ and $[M^{-2}].$ The differential cross section and polarization asymmetries have been calculated for the case when both beams are polarized longitudinally along their directions, as well transversally, in the reaction plane, and normally, perpendicularly to it. Numerical estimations are performed in wide diapason of the collision energy and parameters entering phenomenological Lagrangian.Comment: 17 pages, 7 figure

Bhabha scattering at LEP1. Calorimeter event selection

Analitical calculations have been used to describe the calorimeter event selection in small-angle electron-positron scattering at LEP1. The first-order QED correction to the Born cross-section has been derived with leading log and the next-to-leading log approximations. The second- and the third-order corrections were computed with leading accuracy. The present analytical results are illustated by Tabeles and compared with the corresponding results obtained with the Monte Carlo generator BHLUMI.Comment: 26p., submitted to Journ. of Physics