1,906 research outputs found
Odderon with a running coupling constant
The running coupling is introduced into the equation for the odderon via the
bootstrap relation. It is shown that the previously found odderon state with a
maximal intercept, which is constructed from antisymmetric pomeron wave
function, continues to exist in the running coupling case. Its intercept is
found to remain equal to unity independent of the behaviour assumed for the
running coupling at low momenta.Comment: 9 pages, LaTe
On the inclusive gluon jet production from the triple pomeron vertex in the perturbative QCD
Single and double inclusive cross-sections for gluon jet production from
within the triple pomeron vertex are studied in the reggeized gluon technique.
It is shown that to satisfy the AGK rules the vertex has to be fully symmetric
in all four reggeized gluons which form the two final pomerons. The single
inclusive cross-sections are found for different cuttings of the triple pomeron
vertex. They sum into the expression obtained by Yu.Kovchegov and K.Tuchin in
the colour dipole picture. The found double inclusive cross-sections satisfy
the AGK rules.Comment: 17 pages in LaTex, 6 figures, revised version with partially changed
rsult
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
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.
The Reggeon 2 Reggeons Particle vertex in the Lipatov effective action formalism
The vertex for gluon emission during the splitting of a reggeized gluon into
two is constructed in the framework of Lipatov effective action formalism. Its
reduction to a pure transverse form for the diffractive amplitude gives the
standard Bartels vertex plus an additional contribution corresponding to the
emission from a pointlike splitting vertex. This additional contribution turns
out to be given by a longitudinal integral divergent both in the ultraviolet
and infrared. A certain specific recipe for this part, including the principal
value prescription for the integration, allows to eliminate this unwanted
contribution.Comment: 4 figures; misprints corrected; to be published in Eur.Phys.J.
BKP states in the inclusive gluon production
Inclusive cross-section for gluon production is calculated by the dispersion
technique in the NLO in the perturbative QCD with a large number of colours.
The found cross-section coincides with the one derived in the dipole picture.
No trace of the BKP states is found.Comment: 30 pages, 17 figures. Appendix with a new observation added.
Conclusions changed
BFKL pomeron in the external field of the nucleus in (2+1)-dimensional QCD
The behaviour of the pomeron propagator in the external nuclear field is
studied in the (2+1)-dimensional QCD. It is shown that in the physically
interesting case when the field does not vanish at large rapidities the
propagator in the field vanishes much faster than in the vacuum, in agreement
with the results found in the local Regge-Gribov model. However if the nuclear
field vanishes at high rapidities the field does not change the behaviour of
the pomeron propagator.Comment: 14 pages, 10 figure
Hadron-nucleus scattering in the local reggeon model with pomeron loops for realistic nuclei
Contribution of simplest loops for hadron-nucleus scattering cross-sections
is studied in the Local Reggeon Field Theory with a supercritical pomeron. It
is shown that inside the nucleus the supercritical pomeron transforms into a
subcritical one, so that perturbative treatment becomes possible. The pomeron
intercept becomes complex, which leads to oscillations in the cross-sections.Comment: 13 pages, 6 figure
Elliptic flow from color strings
It is shown that the elliptic flow can be successfully described in the color
string picture with fusion and percolation provided anisotropy of particle
emission from the fused string is taken into account. Two possible sources of
this anisotropy are considered, propagation of the string in the transverse
plane and quenching of produced particles in the strong color field of the
string. Calculations show that the second source gives an overwhelming
contribution to the flow at accessible energies.Comment: 23 pages, 11 figure
Centrality dependence of the multiplicity and transverse momentum distributions at RHIC and LHC and the percolation of strings
The dependence of the multiplicity and the transverse momentum distribution
on the number of collisions are studied for central and peripheral Au-Au
collisions at SPS, RHIC and LHC energies in the framework of percolation of
strings. A scaling law relating the multiplicity to the mean transverse
momentum is obtained. Our results are in overall agreement with the SPS and
RHIC data, obtaining a suppression on distribution even for larger
than 1 GeV/c.Comment: Contribution to QM2002, espcrc1.st
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