Quark Reggeization Research Articles

Regge vertex for quark production in the central rapidity region in the next-to-leading order

The effective vertex for quark production in the interaction of a Reggeized quark and a Reggeized gluon is calculated in the next-to-leading order (NLO). The resulting vertex is the missing component of the NLO multi-Regge amplitude featuring quark and gluon exchanges in the t channels. This calculation will make it possible to develop in future the bootstrap approach to proving quark Reggeization in the next-to-leading logarithmic approximation.

Effective vertex of quark production in collision of a Reggeized quark and gluon

We calculate the effective vertex of the quark production in the collision of a Reggeized quark and a Reggeized gluon in the next-to-leading order (NLO). The vertex in question is the missing component of the multi-Regge NLO amplitudes with the quark and gluon exchanges in the ${t}_{i}$ channels. This multi-Regge form of the amplitudes is the important hypothesis which was recently proved for the gluon exchanges only and remains unverified within the next-to-leading-logarithmic approximation (NLA) for the general case including the quark exchanges. Our calculation allows one to develop the bootstrap approach to the quark Reggeization proof in NLA.

Inclusive jet production at the tevatron collider in the Regge limit of quantum chromodynamics

We consider the inclusive hadroproduction of jets, prompt photons, and b-quark jets in the quasimulti-Regge kinematics approach based on the hypothesis of gluon and quark reggeization in t-channel exchanges at high energies. The data taken by CDF and D0 collaborations at the Fermilab Tevatron collider are well described in the region of \(x_T = 2p_T /\sqrt s \lesssim 0.1\) without the introduction of any free parameters. In numeric calculations we use the Kimber-Martin-Ryskin prescription for unintegrated gluon and quark distribution functions with Martin-Roberts-Stirling-Thorne collinear parton distribution functions taken as input.

Inclusivebandbb¯production with quasi-multi-Regge kinematics at the Tevatron

We consider $b$-jet hadroproduction in the quasi-multi-Regge-kinematics approach based on the hypothesis of gluon and quark Reggeization in $t$-channel exchanges at high energies. The preliminary data on inclusive $b$-jet and $b\overline{b}$-dijet production taken by the CDF Collaboration at the Fermilab Tevatron are well described without adjusting parameters. We find the main contribution to inclusive $b$-jet production to be the scattering of a Reggeized gluon and a Reggeized $b$ quark to a $b$ quark, which is described by the effective Reggeon-Reggeon-quark vertex. The main contribution to $b\overline{b}$-pair production arises from the scattering of two Reggeized gluons to a $b\overline{b}$ pair, which is described by the effective Reggeon-Reggeon-quark-quark vertex. Our analysis is based on the Kimber-Martin-Ryskin prescription for unintegrated gluon and quark distribution functions using as input the Martin-Roberts-Stirling-Thorne collinear parton distribution functions of the proton.

Open charm production at high energies and the quark Reggeization hypothesis

We study open charm production at high energies in the framework of the quasi-multi-Regge-kinematics approach applying the quark-Reggeization hypothesis implemented with Reggeon-Reggeon-particle and Reggeon-particle-particle effective vertices. Adopting the Watt-Martin-Ryskin unintegrated quark and gluon distribution functions of the proton and photon, we thus nicely describe the proton structure function ${F}_{2,c}$ measured at DESY HERA as well as the transverse-momentum distributions of $D$ mesons created by photoproduction at HERA and by hadroproduction at the Fermilab Tevatron.

Prompt photon photoproduction at HERA within the framework of the quark Reggeization hypothesis

We study the inclusive production of isolated prompt photons within the framework of the quasi-multi-Regge-kinematic approach, applying the quark Reggeization hypothesis. We describe accurately and without free parameters the transverse momentum and pseudorapidity spectra of prompt photons in the inclusive photoproduction at the HERA Collider. It is shown that the main mechanism of the inclusive prompt photon production in the $\ensuremath{\gamma}p$ collisions is the fusion of a Reggeized quark (antiquark) from the proton and a collinear antiquark (quark) from the photon into a photon, via the effective Reggeon-quark-gamma vertex. The fragmentation of the quark, which is produced via the gamma-Reggeon-quark and quark-Reggeon-quark vertices, into a photon is strongly suppressed by the isolation cone condition and it gives a significant contribution in the region of a large negative pseudorapidity only. At the stage of numerical calculations we use the Kimber-Martin-Ryskin prescription for unintegrated quark and gluon distribution functions, with the following collinear parton densities as input: Martin-Roberts-Stirling-Thorne for a proton and Gl\"uck-Reya-Vogt for a photon.

Deep inelastic scattering and prompt photon production within the framework of the quark Reggeization hypothesis

We study $ep$ deep inelastic scattering and the inclusive production of prompt photon within the framework of the quasi-multi-Regge-kinematic approach, applying the quark Reggeization hypothesis. We describe structure functions ${F}_{2}$ and ${F}_{L}$ supposing that a virtual photon scatters on a Reggeized quark from a proton, via the effective gamma-Reggeon-quark vertex. It is shown that the main mechanism of the inclusive prompt photon production in $p\overline{p}$ collisions is the fusion of a Reggeized quark and a Reggeized antiquark into a photon, via the effective Regeon-Reggeon-gamma vertex. We describe the inclusive photon transverse momentum spectra measured by the CDF and D0 Collaborations within errors and without free parameters, using the Kimber-Martin-Ryskin unintegrated quark and gluon distribution functions in a proton.

Radiative corrections to the reggeized quark–reggeized quark–gluon effective vertex

This paper is devoted to the calculation of the reggeized quark–reggeized quark–gluon effective vertex in perturbative QCD in the next-to-leading order. The case of QCD with massless quarks is considered and the correction is obtained in the D → 4 limit. This vertex appears in the quark reggeization theory, which next-to-leading order extension is now under construction.

A proof of the reggeized form of amplitudes with quark exchanges

A complete proof of the quark reggeization hypothesis in the leading logarithmic approximation for any quark–gluon inelastic process in the multi-Regge kinematics in all orders of α s is given. First, we show that the multi-Regge form of QCD amplitudes is guarantied if a set of conditions on the reggeon vertices and the trajectories is fulfilled. Then, we examine these conditions and show that they are satisfied.

The quark Regge trajectory at two loops

The hypothesis of the quark Reggeization is tested by taking the high-energy limit of the two-loop amplitude for quark-gluon scattering which was recently calculated. The limit is compatible with the Reggeization in the leading and the next-to-leading orders and allows the determination of the quark trajectory in the two-loop approximation. The trajectory is presented as an expansion in powers of (D-4) for the space-time dimension $D$ tending to the physical value D=4.