36,526 research outputs found
Exclusive photoproduction of meson in and reactions
The amplitude for is calculated in a pQCD -
factorization approach. The total cross section for this process is compared
with HERA data. Total cross section, as a function of photon-proton energy and
photon virtuality, is calculated. We also discuss the ratio of /
and the dependence on the mass of the strange quark. The amplitude
for is used to predict the cross section for exclusive
photoproduction of meson in proton-proton collisions. Absorption effects
are included. The results for RHIC, Tevatron and LHC energies are presented.Comment: 10 pages, 5 figure
Non-dopplerian cosmological redshift parameters in a model of graviton-dusty universe
Possible effects are considered which would be caused by a hypothetical
superstrong interaction of photons or massive bodies with single gravitons of
the graviton background. If full cosmological redshift magnitudes are caused by
the interaction, then the luminosity distance in a flat non-expanding universe
as a function of redshift is very similar to the specific function which fits
supernova cosmology data by Riess et al. From another side, in this case every
massive body, slowly moving relatively to the background, would experience a
constant acceleration, proportional to the Hubble constant, of the same order
as a small additional acceleration of Pioneer 10, 11.Comment: 5 pages. It was presented: at SIGRAV'2000 Congress, Italy (this
version); in Proc. of the Int. Symp. "FFP 4" (9-13 Dec 2000, Hyderabad,
India), Sidharth& Altaisky, Eds., Kluwer Academic/Plenum, 2001;in Proc. of
the 4th Edoardo Amaldi Conference on GW (Perth, W. Australia, 8-13 July 2001
Allowed charge transfers between coherent conductors driven by a time-dependent scatterer
We derive constraints on the statistics of the charge transfer between two
conductors in the model of arbitrary time-dependent instant scattering of
non-interacting fermions at zero temperature. The constraints are formulated in
terms of analytic properties of the generating function: its zeroes must lie on
the negative real axis. This result generalizes existing studies for scattering
by a time-independent scatterer under time-dependent bias voltage.Comment: 5 pages, no figures, corrected misprints and minor changes in version
Linear and nonlinear realizations of superbranes
The coordinate transformations which establish the direct relationship
between the actions of linear and nonlinear realizations of supermembranes are
proposed. It is shown that the Rocek-Tseytlin constraint known in the framework
of the linear realization of the theory is simply equivalent to a limit of a
"pure" nonlinear realization in which the field describing the massive mode of
the supermembrane puts to zero.Comment: 8 pages, LaTeX + espcrc2.sty The talk given at the D. Volkov Memorial
Conference SQFT, July, 25-29, 200
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