30 research outputs found
Quark-antiquark contribution to the BFKL kernel
The quark-antiquark contribution to the BFKL kernel is calculated. Using the
effective vertex for the pair production in the Reggeon-Reggeon
collision we find this contribution by integrating the square of this vertex
over relative transverse momenta and fractions of longitudinal momenta of
produced particles.Comment: 12 pages, Late
Gribov's Theorem on Soft Emission and the Reggeon-Reggeon-Gluon Vertex at Small Transverse Momentum
In spite of the fact that the Gribov's theorem about the region of
applicability of the soft emission factorization cannot be referred literally
to the case of massless charged particles, it can be used for the calculation
of soft emission amplitudes in such a case also. We demonstrate this for the
gluon production amplitude in the multi-Regge kinematics with small transverse
momentum.Comment: 9 pages, Late
NLO inclusive jet production in --factorization
The inclusive production of jets in the central region of rapidity is studied
in -factorization at next-to-leading order (NLO) in QCD perturbation
theory. Calculations are performed in the Regge limit making use of the NLO
BFKL results. A jet cone definition is introduced and a proper phase--space
separation into multi-Regge and quasi-multi-Regge kinematic regions is carried
out. Two situations are discussed: scattering of highly virtual photons, which
requires a symmetric energy scale to separate the impact factors from the gluon
Green's function, and hadron-hadron collisions, where a non--symmetric scale
choice is needed.Comment: 36 pages, 5 figures. Version to be published in JHEP. Some typos
correcte
The impact factor for the virtual photon to light vector meson transition
We evaluate in the next-to-leading approximation the forward impact factor
for the virtual photon to light vector meson transition in the case of
longitudinal polarization. We find that in the hard kinematic domain, both in
the leading and in the next-to-leading approximation, the expression for the
impact factor factorizes, up to power suppressed corrections, into the
convolution of a perturbatively calculable hard-scattering amplitude and a
meson twist-2 distribution amplitude.Comment: 31 pages latex; few comments and one reference added; version to
appear in Eur. Phys. Journal
Photon-Reggeon Interaction Vertices in the Nla
We calculate the effective vertices for the quark-antiquark and the
quark-antiquark-gluon production in the virtual photon - Reggeized gluon
interaction. The last vertex is considered at the Born level; for the first one
the one-loop corrections are obtained. These vertices have a number of
applications; in particular, they are necessary for calculation of the virtual
photon impact factor in the next-to-leading logarithmic approximation.Comment: 20 pages, references adde
The Gluon Impact Factors
We calculate in the next-to-leading approximation the non-forward gluon
impact factors for arbitrary color state in the -channel. In the case of the
octet state we check the so-called "second bootstrap condition" for the gluon
Reggeization in QCD, using the integral representation for the impact factors.
The condition is fulfilled in the general case of an arbitrary space-time
dimension and massive quark flavors for both helicity conserving and
non-conserving parts.Comment: 32 pages, LaTeX, 1 EPS figure, uses epsf.sty and axodraw.st
The Quark Impact Factors
We calculate in the next-to-leading approximation the non-forward quark
impact factors for both singlet and octet color representation in the
-channel. The integral representation of the octet impact factor in the
general case of arbitrary space-time dimension and massive quark flavors is
used to check the so-called "second bootstrap condition" for the gluon
Reggeization at the next-to-leading logarithmic approximation in perturbative
QCD. We find that it is satisfied for both helicity conserving and
non-conserving parts. The integrations are then performed for the explicit
calculation of the impact factors in the massless quark case.Comment: 23 pages, LaTeX, 1 EPS figure, uses epsf.sty and axodraw.st