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Journal ArticleDOI

Target mass and finite momentum transfer corrections to unpolarized and polarized diffractive scattering

TL;DR: In this article, a quantum field theoretic treatment of deep-inelastic diffractive scattering is given, where different diffractive structure functions are expressed through integrals over the relative momentum of non-perturbative t-dependent 2-particle distribution functions.
About: This article is published in Nuclear Physics.The article was published on 2006-10-30 and is currently open access. It has received 16 citations till now. The article focuses on the topics: Momentum transfer & Parton.

Summary (1 min read)

1 Introduction

  • This ratio still awaits a rigorous non-perturbative explanation.
  • In section 3 the symmetric part of the Compton amplitude is dealt with, through which the diffractive structure functions for unpolarized nucleons are derived.
  • The polarized structure functions are determined in section 4.
  • In section 5 the authors derive relations between different structure functions and section 6 contains the conclusions.

5 Relations between Diffractive Structure Functions

  • The situation is more involved for the case studied in the present paper, since the structure functions emerge as a ζ−integral of sub-system structure functions, which accounts for the twoparticle nature of the wave-function.
  • Thus the corresponding relations can be established for the un-integrated ζ-dependent functions only.

5.1 Unpolarized Case

  • (5.5) Three of the above distribution functions are independent.
  • As shown in section 3 the respective linear combinations are weighted by different ζ-dependent functions, that in general no relations exist on the level of structure functions.

6 Conclusions

  • The presence of target mass and t-effects enlarges the number of structure functions determining the hadronic tensor.
  • In the unpolarized case four structure functions contribute, which cannot be related to each other directly.
  • In the polarized case the Wandzura-Wilzcek relation remains unbroken and holds even separately for the contributions to the different invariants K a | 5 a=3 .
  • The present formalism can be used in experimental analysis of deep-inelastic diffractive scattering data referring to suitable models for the un-integrated distribution functions depending on ζ, for which rigorous determination using methods of non-perturbative QCD do not yet exits.
  • In this way the structures being derived in the present paper can be tested.

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Citations
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Journal ArticleDOI
TL;DR: In this article, the authors considered the off-cone twist-2 light-cone operators to derive the target mass and finite $t$ corrections to diffractive deep-inelastic scattering.
Abstract: The quantum field theoretic treatment of inclusive deep--inelastic diffractive scattering given in a previous paper \cite{BGR2006} is discussed in detail using an equivalent formulation with the aim to derive a representation suitable for data analysis. We consider the off-cone twist--2 light-cone operators to derive the target mass and finite $t$ corrections to diffractive deep--inelastic scattering and deep--inelastic scattering. The corrections turn out to be at most proportional to $x |t|/Q^2, x M^2/Q^2, x = x_{\rm BJ} {\rm or} x_\PP$, which suggests an expansion in these parameters. Their contribution varies in size considering diffractive scattering or meson--exchange processes. Relations between different kinematic amplitudes which are determined by one and the same diffractive GPD or its moments are derived. In the limit $t, M^2 \to 0$ one obtains the results of \cite{Blumlein:2001xf} and \cite{Blumlein:2002fw}.

11 citations

Journal ArticleDOI
F. D. Aaron, Calin Alexa, Vladimir Andreev1, S. Backovic2  +200 moreInstitutions (31)
TL;DR: In this article, the diffractive longitudinal structure function F(L)(D) in the range of photon virtualities 4.0 <= Q(2) <= 44.0 GeV(2), and fractional proton longitudinal momentum loss 5 x 10(-4) <= x(P) <= 3x 10(-3).
Abstract: First measurements are presented of the diffractive cross section sigma(ep) -> eXY at centre-of-mass energies root s of 225 and 252 GeV, together with a precise new measurement at root s of 319 GeV, using data taken with the H1 detector in the years 2006 and 2007. Together with previous H1 data at root s of 301 GeV, the measurements are used to extract the diffractive longitudinal structure function F(L)(D) in the range of photon virtualities 4.0 <= Q(2) <= 44.0 GeV(2) and fractional proton longitudinal momentum loss 5 x 10(-4) <= x(P) <= 3 x 10(-3). The measured F(L)(D) is compared with leading twist predictions based on diffractive parton densities extracted in NLO QCD fits to previous measurements of diffractive Deep-Inelastic Scattering and with a model which additionally includes a higher twist contribution derived from a colour dipole approach. The ratio of the diffractive cross section induced by longitudinally polarised photons to that for transversely polarised photons is extracted and compared with the analogous quantity for inclusive Deep-Inelastic Scattering.

11 citations

Journal ArticleDOI
TL;DR: In this paper, a general approach to the calculation of target mass and finite t=(p'-p)^2 corrections in hard processes which can be studied in the framework of the operator product expansion and involve momentum transfer from the initial to the final hadron state was developed.
Abstract: We develop a general approach to the calculation of target mass and finite t=(p'-p)^2 corrections in hard processes which can be studied in the framework of the operator product expansion and involve momentum transfer from the initial to the final hadron state. Such corrections, which are usually referred to as kinematic, can be defined as contributions of operators of all twists that can be reduced to total derivatives of the leading twist operators. As the principal result, we provide a set of projection operators that pick up the "kinematic" part of an arbitrary flavor-nonsinglet twist-four operator in QCD. A complete expression is derived for the time-ordered product of two electromagnetic currents that includes all kinematic corrections to twist-four accuracy. The results are immediately applicable to the studies of deeply-virtual Compton scattering, transition gamma^*-> M gamma form factors and related processes. As a byproduct of this study, we find a series of "genuine" twist-four flavor-nonsinglet quark-antiquark-gluon operators which have the same anomalous dimensions as the leading twist quark-antiquark operators.

4 citations

01 Jan 1999
TL;DR: In this paper, the handbag contribution to Compton scattering at moderately large momentum transfer factorises into parton-photon subprocess amplitudes and new form factors representing 1/x -moments of skewed parton distributions.
Abstract: Abstract The handbag contribution to Compton scattering at moderately large momentum transfer factorises into parton-photon subprocess amplitudes and new form factors representing 1/ x -moments of skewed parton distributions. A detailed phenomenological study for polarised and unpolarised real and virtual Compton scattering is presented.

3 citations

References
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Book
27 May 1977
TL;DR: The theory of the complex angular momentum plane (Regge theory) as discussed by the authors was proposed by Regge in the early 1970s to explain the forces between these particles and predict the results of high-energy scattering experiments.
Abstract: Originally published in 1977, this book presents an extended introduction to the theory of hadrons, the elementary particles which occur in the atomic nucleus The main emphasis is on the theory of the complex angular momentum plane 'Regge theory', which has grown from Regge's demonstration in 1959 that it is useful to regard angular momentum as a complex variable when discussing solutions of the Schrodinger equation for non-relativistic potential scattering This theory helps to classify the many different particles which have been discovered in recent years, to explain the forces between these particles and to predict the results of high-energy scattering experiments Regge theory thus serves as a unifying concept drawing together many different features of high-energy physics This monograph is intended primarily for research students just beginning to concern themselves with particle physics, but more experienced workers will also find much to interest them in this detailed survey of the basic ideas and results of Regge theory

1,024 citations

01 May 2009
TL;DR: The theory of the complex angular momentum plane (Regge theory) as discussed by the authors was proposed by Regge in the early 1970s for non-relativistic potential scattering and has been used to classify the many different particles which have been discovered in recent years, to explain the forces between these particles and to predict the results of high-energy scattering experiments.
Abstract: Originally published in 1977, this book presents an extended introduction to the theory of hadrons, the elementary particles which occur in the atomic nucleus. The main emphasis is on the theory of the complex angular momentum plane 'Regge theory', which has grown from Regge's demonstration in 1959 that it is useful to regard angular momentum as a complex variable when discussing solutions of the Schrodinger equation for non-relativistic potential scattering. This theory helps to classify the many different particles which have been discovered in recent years, to explain the forces between these particles and to predict the results of high-energy scattering experiments. Regge theory thus serves as a unifying concept drawing together many different features of high-energy physics. This monograph is intended primarily for research students just beginning to concern themselves with particle physics, but more experienced workers will also find much to interest them in this detailed survey of the basic ideas and results of Regge theory.

912 citations

Journal ArticleDOI
TL;DR: In this article, the asymptotic behavior of electroproduction cross sections is shown to contain information about the constitution of the electric current, and it is shown that the cross sections are a good indicator of the strength of electric currents.
Abstract: The asymptotic behavior of electroproduction cross sections is shown to contain information about the constitution of the electric current.

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TL;DR: In this article, the cross section for the process p + p → p + X, where X contains two high-pt jets, was estimated with the assumption of an effective gluon distribution for the pomeron structure.

489 citations

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TL;DR: Wilson's operator product expansion is examined in this article, where it is shown how to project on operators of definite spin at finite Q2 consistency conditions for anomalous dimensions following from positivity using the moment problem.

409 citations

Frequently Asked Questions (1)
Q1. What are the contributions mentioned in the paper "Target mass and finite momentum transfer corrections to unpolarized and polarized diffractive scattering" ?

The different diffractive structure functions are expressed through integrals over the relative momentum of non–perturbative t–dependent 2–particle distribution functions.