48,640 research outputs found
On the initial condition for evolution of the perturbative QCD Pomeron in the nucleus
It is shown that subdominant terms found in the reggeized gluon diagram
technique, to be added to Pomeron fan diagrams with the 3P interaction, can be
exactly taken into account by taking the initial condition for evolution in the
Glauber form. This demonstrates complete equivalence of the dipole picture and
the reggeized gluon approach not only on the leading level but also on the
subleading level.Comment: 5 pages in LaTe
Conformal invariant pomeron interaction in the perurbative QCD with large N_c
An effective non-local quantum field theory is constructed, which describes
interaction of pomerons in the high-coloured QCD. The theory includes both
splitting and merging triple pomeron vertexes and diagrams with pomeronic
loops. The Schwinger-Dyson equations for the 'physical' pomeron are written.
Conformal invariance allows to reduce the theory to the old-fashioned Gribov
pomeron theory with an infinite number of pomerons, one of which is
supercritical.Comment: 20 pages in LaTe
On the inclusive gluon jet production off the nucleus in the perturbative QCD
In the perturbative QCD approach single and double inclusive cross-sections
for gluon production off the nucleus are studied from the relevant reggeized
gluon diagrams. Various terms corresponding to emission of gluons from the
triple Pomeron vertex are found. Among them the term derived by Kovchegov and
Tuchin emerges as a result of transition from the diffractive to effective
high-energy vertex. However it does not exhaust all the vertex contributions to
the inclusive cross-section. In the double inclusive cross-section a
contribution violating naive AGK rules is found, in which one gluon is emitted
from the vertex and the other from one of the Pomerons below the vertex. But
then this contribution is subdominant at high energies and taking it into
account seems to be questionable.Comment: 22 pages in LaTex, inclusing 7 figure
coupling constant in light cone QCD sum rules
We employ the light cone QCD sum rules to calculate coupling
constant by studying the two point correlation function between the vacuum and
the pion state. Our result is consistent with the traditional QCD sum rules
calculations and it is in agreement with the experimental value.Comment: 8 pages, latex, 2 figure
Production of a gluon with the exchange of three reggeized gluons in the Lipatov effective action approach
In the Regge kinematics the amplitude for gluon production off three
scattering centers is found in the Lipatov effective action technique. The
vertex for gluon emission with the reggeon splitting in three reggeons is
calculated and its transversality is demonstrated. It is shown that in the sum
of all contributions terms containing principal value singularities are
cancelled and substituted by the standard Feynman poles. These results may be
used for calculation of the inclusive cross-section for gluon production on two
nucleons in the nucleus.Comment: 22 pages, 9 figures; submitted to Eur.Phys.Jour.
Loops in the gluon emission amplitude: reggeization from the Glauber scattering
It is shown that in the Glauber scattering of a fast quark in the external
field loop corrections to the gluon emission amplitude due to virtual softer
gluon after renormalization coincide with a correction due to reggeization of
the exchanged gluon in the BFKL picture.Comment: 26 pages, 10 figure
Participatory action research on climate risk management, Bangladesh
The rural populations of southern Bangladesh are some of the most vulnerable communities in the world to the future impacts of climate change. They are particularly at risk from floods, waterlogged soils, and increasing salinity of both land and water. The objective of this project was to analyze the vulnerability of people in four villages that are experiencing different levels of soil salinity. The study evaluated the strengths and weaknesses of current coping strategies and assessed the potential of an index-based insurance scheme, designed diversification and better information products to improve adaptive capacity
Double inclusive cross-sections for gluon production in collision of two projectiles on two targets in the BFKL approach
Double inclusive cross-sections for gluon production in collision of two
nucleons with two nucleons are studied in the BFKL approach. Various
contributions include emission from the pomerons attached to the participants,
from the BFKL interactions between these pomerons and from the intermediate BKP
state. The last contribution may be observable provided the growth with energy
of the pomeron contribution is tamed in accordance with unitarity. Possibility
of long-range azimuthal correlations due to the BKP state are discussed.Comment: arXiv admin note: substantial text overlap with arXiv:1305.171
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