12 research outputs found
Strong Bootstrap Conditions
We reformulate the so-called ``strong bootstrap'' conditions for the gluon
Reggeization in the next-to-leading approximation (NLA), firstly suggested by
Braun and Vacca, using a different approach, which is not based on properties
of the eigenstates of the NLA octet BFKL kernel. We write the second strong
bootstrap condition for the NLA octet impact factors in a form which makes
clear their dependence on the process. According to this condition, the NLA
octet impact factors must be given by the product of the corresponding Reggeon
interaction vertices with a universal coefficient function. This function can
be used also in the formulation of the first strong bootstrap condition for the
NLA BFKL kernel in the octet state.Comment: 10 page
Radiative corrections to the quark-gluon-Reggeized quark vertex in QCD
This paper is devoted to the calculation of the quark-gluon-Reggeized quark
effective vertex in perturbative QCD in the next-to-leading order. The case of
QCD with massive quarks is considered. This vertex has a number of
applications, in particular, the result can be used for determination of the
next-to-leading correction to the massive Reggeized quark trajectory.Comment: 13 pages, LaTeX, uses axodraw.st
On the Calculation of the NLO Virtual Photon Impact Factor
The definition of the virtual photon impact factor involves the integration
of the s-channel discontinuity of the photon-Reggeon scattering amplitude over
the right cut. It permits to formulate a new approach for the calculation of
the impact factor based on analytical properties of the amplitude in question.
In the next-to-leading order it may give a possibility for considerable
simplification of the calculation. We have shown that a part of the diagrams
contributing to the impact factor can be treated without their real
calculation.Comment: 18 pages, latex, axodraw.sty for figures, version to appear in Nucl.
Phys.
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
Calculation of Reggeon Vertices in QCD
The method of calculation of effective vertices of interaction of the
Reggeized gluon and quark with particles in QCD in the next-to-leading order is
developed. The method is demonstrated in the case of already known vertices of
both gluon-gluon and quark-quark transitions in the scattering of gluons and
quarks on the Reggeized gluon. It is used for the calculation of the
gluon-quark transition in the scattering on the Reggeized quark.Comment: 27 pages, LaTex, 1 figure, uses axodraw.st
The quark part of the non-forward BFKL kernel and the ``bootstrap'' for the gluon Reggeization
We calculate the quark part of the kernel of the generalized non-forward BFKL
equation at non-zero momentum transfer in the next-to-leading logarithmic
approximation. Along with the quark contribution to the gluon Regge trajectory,
this part includes pieces coming from the quark-antiquark production and from
the quark contribution to the radiative corrections in one-gluon production in
the Reggeon-Reggeon collisions. The results obtained can be used for an
arbitrary representation of the colour group in the channel. Using the
results for the adjoint representation, we demonstrate explicitly the
fulfillment of the ``bootstrap'' condition for the gluon Reggeization in the
next-to-leading logarithmic approximation in the part concerning the quark
contribution.Comment: 26 pages, LaTeX, uses axodraw.sty; revised final comment; to appear
on Phys. Rev.
Renormalization Group Effects in the Process
The partial Higgs width is
important at the LHC for Higgs masses in the MSSM mass window up to 140 GeV as
a relatively background free signal of a fundamental scalar. At the photon
photon mode at the NLC it would be the Higgs production mechanism . Two loop
QCD corrections exist for the fermionic contribution and in the case of the
bottom loop large non-Sudakov double logarithms can be resummed to all orders
and contribute up to 12 % compared to the t-quark. In more complicated Higgs
sectors, such as in the MSSM, large enhancements of bottom type
Yukawa couplings can potentially dominate even the whole partial width. A main
uncertainty in all existing calculations is the scale of the strong coupling as
it is only renormalized at the three loop level. In this paper we include the
exact two loop running coupling to all orders into the bottom contribution. We
find that the effective scale is close to .Comment: 10 pages, 2 figures, submitted to Phys. Rev. Let