13,587 research outputs found
Feasibility of finite renormalization of particle mass in quantum electrodynamics
The paper proposes an algorithm for regularization of the self-energy
expressions for a Dirac particle that meets the relativistic and gauge
invariance requirements.Comment: REVTEX, 9 pages, 1 table, submitted to RR
Nonlinearity of vacuum reggeons and exclusive diffractive production of vector mesons at HERA
The processes of exclusive photo- and electroproduction of vector mesons
(770), (1020) and (3096) at collision energies and transferred momenta squared are considered in
the framework of a phenomenological Regge-eikonal scheme with nonlinear Regge
trajectories in which their QCD asymptotic behavior is taken into account
explicitly. By comparison of available experimental data from ZEUS and H1
Collaborations with the model predictions it is demonstrated that corresponding
angular distributions and integrated cross-sections in the above-mentioned
kinematical range can be quantitatively described with use of two -even
vacuum Regge trajectories. These are the "soft" pomeron dominating the high
energy reactions without a hard scale and the "hard" pomeron giving an
essential contribution to photo- and electroproduction of heavy vector mesons
and deeply virtual electroproduction of light vector mesons.Comment: 25 pages, 12 figure
Transient currents in a molecular photo-diode
Light-induced charge transmission through a molecular junction (molecular
diode) is studied in the framework of a HOMO-LUMO model and in using a kinetic
description. Expressions are presented for the sequential (hopping) and direct
(tunneling) transient current components together with kinetic equations
governing the time-dependent populations of the neutral and charged molecular
states which participate in the current formation. Resonant and off-resonant
charge transmission processes are analyzed in detail. It is demonstrated that
the transient currents are associated with a molecular charging process which
is initiated by photo excitation of the molecule. If the coupling of the
molecule to the electrodes is strongly asymmetric the transient currents can
significantly exceed the steady state current.Comment: 17 pages, 12 figures, accepted for publication in Chemical Physic
Can universality of the QCD evolution be checked in W boson decays into hadrons?
Hadron multiplicity from boson is calculated in pQCD. The agreement of
our theoretical predictions with the LEP data says in favor of universality of
the QCD evolution in hard processes.Comment: 14 pages, 7 figure
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