Phenomenological Behavior of the Hard Pomeron Intercept

The hard pomeron intercept value is determined by the decoupling solutions of the Dokshitzer-Gribov-Lipatov-Altarelli-Parisi (DGLAP) evolution equations at low-x. The unpolarized proton structure functions at next-to-next-to-leading order (NNLO) analysis are calculated and compared with new Hadron-Electron Ring Accelerator (HERA) data.     

Average nonlinear duality and the Pomeron for two-body and inclusive processes

A simple scheme combining duality with unitarity is applied to exotic ππ and π-Reggeized-? scattering. The resulting ??P triple-Regge vertex is in agreement with recent fits to inclusive cross sections. An extension to nonexotic channels is also discussed.     

Associated J/ψ+γ Production Through Double Pomeron Exchange: the Nature of the Pomeron and Hard Diffractive Factorization Breaking

We present a study of associated J/ψ+γ production through double pomeron exchange at energies reached at the Fermilab Tevatron.and CERN LHC based on the Ingelman-Schlein model for hard difiactive scattering and the factorization formalism of nonrelativistic QCD for quarkonia production. We find that the process p+p→p +p + J/ψ+γ + X can be used to probe the gluon content of the pomeron and study the nature of hard difiactive factorization breaking.     

A Pomeron model which needs no decoupling

We present a model in which the Pomeron is a related pair of factorizable Regge poles both with intercept one. Our model requires a cut (fixed or moving) with a branch point intercept one. In this model the triple Pomeron vertex need not vanish and as a result the Pomeron may couple to asymptotically constant cross sections. Our model can even fit pp elastic scattering data moderately well.     

The Pomeron in Closed Bosonic String Theory

We review the features of the pomeron in the S-matrix theory and in quantum field theory. We extend those general properties to the pomeron of closed bosonic string theory in a Minkowskian background. We compute the couplings of the pomeron to the first few mass levels of closed bosonic string states in flat space. We recognize the deviation from the linearity of the Regge trajectories in a five dimensional anti De Sitter background.     

An NLO QCD analysis of inclusive cross-section and jet-production data from the ZEUS experiment

The ZEUS inclusive differential cross-section data from HERA, for charged and neutral current processes taken with e ⁺ and e^- beams, together with differential cross-section data on inclusive jet production in e ⁺ p scattering and dijet production in scattering, have been used in a new NLO QCD analysis to extract the parton distribution functions of the proton. The input of jet-production data constrains the gluon and allows an accurate extraction of at NLO; An additional uncertainty from the choice of scales is estimated as . This is the first extraction of from HERA data alone.     

The QCD Pomeron with optimal renormalization

It is shown that the next-to-leading order (NLO) corrections to the QCD Pomeron intercept obtained from the Balitsky-Fadin-Kuraev-Lipatov (BFKL) equation, when evaluated in non-Abelian physical renormalization schemes with Brodsky-Lepage-Mackenzie (BLM) optimal scale setting, do not exhibit the serious problems encountered in the scheme. A striking feature of the NLO BFKL Pomeron intercept in the BLM approach is that it yields an important approximate conformal invariance. Pis’ma Zh. éksp. Teor. Fiz. 70, No. 3, 161–166 (10 August 1999) Published in English in the original Russian journal. Edited by Steve Torstveit.     

Deep-inelastic one-particle inclusive processes in the parton model

We study the processes e + N → e′ + h + anything, e⁺ + e^? → h + anything, within the parton model of Landshoff, Polkinghorne and Short. Definite and peculiar predictions are obtained, also common to the Drell, Levy and Yan cut-off theory and to the λφ³ ladder model. These predictions can be summarized as follows: (i) in the photon fragmentation region the cross section factorizes after integration over transverse momentum of h; (ii) in the target fragmentation region Regge behaviour, valid at large ω, gives rise to double Regge exchange for small values of the Feynman variable y, but only up to $\text{y ??1/ω}$; (iii) the structure functions vanish at y = 0; (iv) total multiplicities in the first process increase like 1n ω for large ω, and in the second reach a finite limit at large q².In the case where only one SU(3) multiplet of partons is present (as in the quark parton model) unique relations, valid in the limit of exact SU(3), are found between the cross section and multiplicities in the first process and the analogous quantities for the forward region of the second process.     

The origin of a high-energy scale in the Pomeron calculus

The Gribov-Reggeon calculus, whose perturbative expansion is expected to converge at low energy, is known to give rise to critical phenomena at ultra-high energies. The aim of this paper is to investigate the transition between these two regimes and to determine the scale with which this transition happens. This is done by solving exactly the renormalization group equation in a model theory. The propagator shows a singularity whose position determines the scale in question. The dynamical origin of this scale — whose evaluation situates it beyond present machine energies — is discussed, and so the dual relation between the perturbative and the critical expansions.     

Pomeron的胶子内容

指出Pomeron可以被看作为具有Regge轨道α_p(t)=1.08+0.2GeV^－2t的Regge化的胶子球.理论成功地预言了实验上观测到的质子一质子弹性散射的总截面.理论与实验的最好符合给出了张量胶子球到质子反质子道的衰变宽度为9±3MeV,其总宽度大于50MeV.并且排除了张量胶子球的自旋为4的可能性.     

Infrared behaviour and the bare Pomeron intercept in a Reggeon Field Theory including the Pomeron and thef-pole

An extension of the critical Reggeon Field Theory that includes both the Pomeron and thef-Reggeon fields is constructed. The quantum numbers of thef-Reggeon allows specific Reggeon-Pomeron couplings that have not been considered previously in standard works on secondary trajectories. We show the existence of a single fully stable fixed point among a total of 11 points. Unfortunately this point does not satisfy the factorization requirements imposed by thef-dominance of the Pomeron hypothesis and, in consequence, the critical Pomeron can not bef-dominated in aP+f model. We have also evaluated the value of the intercept of the bare critical Pomeron, using the method of integral representations of the propagators. The value obtained is clearly higher than the one previously obtained without thef-Pomeron interplay. With an adequate choice of the values of the bare coupling constants its value is in good agreement with the phenomenological one.     

On the self-consistent Pomeron pole

A model is considered in which a Pomeron is regarded as a self-consistent intercept one Regge pole resulting from a Bethe-Salpeter-like equation in Reggeon theory. The absorptive nature of a two Pomeron cut is crucial for realization of self-consistency. For zero mass Pomerons the model predicts the vanishing of the triple Pomeron coupling and softening of Pomeron cut contributions to inclusive reactions in triple and di-triple Regge regions.     

关于软玻密子的结构

本文修改了Landshoff-Nachtmann的软玻密子(Pomeron P)场论模型.从强子组分夸克具有结构的观点出发,根据高能强作用软过程中的最大非微扰强作用反应假定,提出了有关软P新的结构图像.对撞强子中的一对组分夸克被分解为裸夸克和一系列非微扰胶子(和夸克对).与此相应,软P的结构是由胶子形成的一系列切割梯形图之和所代表.在系统能量s很大而动量转移|t|很小的多重雷吉(Regge)运动学区间,并在保留lns的领头阶近似下,计算了这组切割梯形图之和所对应的散射振幅和总截面.它们的表达式出现了对s的Regge型幂次因子,得出了软P轨迹的简洁表达式.简单说明了按本文提出的方案可以讨论那些相关的强作用过程.     

Two-photon contributions to the Rosenbluth cross-section in the Skyrme model

We study two-photon contributions to the elastic electron-nucleon scattering within the Skyrme model. In particular we focus on the role of the anomaly that enters via the Wess-Zumino term and explain how this induces an axial current interaction.     

The Pomeron and the scaling law for partial wave amplitudes

From the scaling law for the s-channel partial wave amplitudes, which guarantees simultaneously t-channel unitarity at threshold t = 4μ² and s-channel unitarity, we derive: (i) The intercept α(0) of the Pomeron is always one, if α(4μ²) > 1. (ii) The total and the elastic cross sections are bounded from below for s → ∞.

where α(4μ²) and δ(4μ²) are the position and the type of te Pomeron singularity (J ? α(4μ²))^{?1?δ(4μ2) at t = 4μ2}. (iii) The type of the Pomeron singularity δ(4μ²) is restricted: either $\text{δ(4μ}{}^2\text{) ?}\text{1}\text{2}$ or $\text{δ(4μ}{}^2\text{) ?}\text{1}\text{2}$.     

Pomeron factorization in general dual models

We demonstrate that in each ghost-free dual model with one minor restriction, there exists a critical dimensionality of space-time in which the pomeron singularity becomes a factorizable Regge pole. In each model when this dimensionality is chosen, the pomeron emerges with twice the intercept and half the slope of the leading secondary (f) trajectory. We explicitly construct the pomeron propagator and the operator coupling the pomeron to the reggeon sector for the general dual model, including the lower-lying negative-G-parity pomeron in the Neveu-Schwarz model. Gauge identities and physical states in the pomeron sector are also investigated. In all of the dual models the pomeron form factors exhibit a generalized f dominance and modified Wu-Yang behavior.