18,231 research outputs found
Polarization of the electron and positron produced in combined Coulomb and strong laser fields
The process of production in the superposition of a Coulomb and a
strong laser field is considered. The pair production rate integrated over the
momentum and summed over the spin projections of one of the particles is
derived exactly in the parameters of the laser field and in the Born
approximation with respect to the Coulomb field. The case of a monochromatic
circularly polarized laser field is considered in detail. A very compact
analytical expression of the pair production rate and its dependence on the
polarization of one of the created particles is obtained in the quasiclassical
approximation for the experimentally relevant case of an undercritical laser
field. As a result, the polarization of the created electron (positron) is
derived.Comment: 16 pages, no figure
Multidimensional Worldline Instantons
We extend the worldline instanton technique to compute the vacuum pair
production rate for spatially inhomogeneous electric background fields, with
the spatial inhomogeneity being genuinely two or three dimensional, both for
the magnitude and direction of the electric field. Other techniques, such as
WKB, have not been applied to such higher dimensional problems. Our method
exploits the instanton dominance of the worldline path integral expression for
the effective action.Comment: 22 pages, 13 figure
Study of narrow baryon resonance decaying into in -interactions at with SVD-2
The inclusive reaction was studied at IHEP accelerator
with proton beam using SVD-2 detector. Two different samples of
, statistically independent and belonging to different phase space
regions were used in the analyses and a narrow baryon resonance with the mass
was observed in both samples of the
dataComment: 3 pages, 6 figures, to be published in the Proceedings of the XXXIII
International Conference of High Energy Physics (ICHEP'06), Moscow, 200
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