Deep Inelastic Region Research Articles

Single-particle spectra at fixed angle and duality

A dual resonance amplitude with satellites is applied in order to study the inclusive reactions a + b → x + anything at high energies and at fixed c.m.s. angle of the produced particle. Comparing the asymptotic expansion in this deep inelastic region with the one in the triple-Regge region, it turns out that the contributions of the satellite terms can be expressed by a function which is the same, but which appears with different arguments, in both limits. On the basis of this relationship between small- and large-angle scattering, a dependence of the shapes of single-particle distributions at large angles on the quantum numbers of the channel (a x ) can be predicted.

Model-Independent Deep-Inelastic Electroproduction Sum Rules

Using the most general form for the null-plane commutator of the electromagnetic current, sum rules are derived for electroproduction in the deep-inelastic region. The structure of these sum rules is discussed and a free, massless, fermion model is considered as an illustration.

Analysis of photo and electroproduction data against ω W

A detailed analysis is made of scaling and local duality of the two structure functions W 1 and νW 2 characterizing inelastic electron scattering, against the variable ωW = 2Mυ + M W 2 q 2 + a 2 For this purpose a compilation of world data spanning the resonance and deep inelastic region and including photoproduction has been used. It is shown that to the accuracy allowed by present experiments, ω W is a good variable for all ν and q 2 values, including real photons.

Lepton-Hadron Collisions in a Sub-Urbaryonic Composite Model

It is widely believed that the lepton-hadron (l-H) collisions play important roles in studying the internal structure of hadrons. In this paper we assume that the suburbaryonic structure of hadrons makes its appearance in the deep inelastic l-H scattering processes. Using a model analogous to the so-called Nagoya model,rl we give rather good results for l-H scatterings in the deep inelastic region. In § 2, we propose a model for elementary particles. In § 3 we review briefly the kinematics for l-H collisions. In § 4, the structure functions for e-H collisions are explicitely calculated according to our model, and in § 5, the predictions for v (D) -N (N: nucleon) collisions are given. And :finally in § 6, we discuss further problems and compare the results with those of other models. In the Appendix, we derive the probability distribution functions of longitudinal momentum fraction which are needed in order to calculate the structure functions using a parton model. 5 ) § 2. Model

Erratum to: Pion electroproduction in the deep inelastic region as a means to measure the dimension of chiral-symmetry breaking

Erratum to: Pion electroproduction in the deep inelastic region as a means to measure the dimension of chiral-symmetry breaking

Regge-pole analysis of ρ photoproduction and ρ electroproduction in deep inelastic region

Regge-pole analysis of ρ photoproduction and ρ electroproduction in deep inelastic region

Pion electroproduction in the deep inelastic region as a mean to measure the dimension of chiral-symmetry breaking

Pion electroproduction in the deep inelastic region as a mean to measure the dimension of chiral-symmetry breaking

Inelastic e-p scattering in massive quantum electrodynamics

We calculate, in the deep inelastic region, the leading contributions to νW 2 in the neutral vector gluon model. Scaling is broken by ln Q 2 factors which come from both transverse and longitudinal phase-space integrations and which exponentiate.

Electroproduction from Nucleons in a Relativistic Quark Model

A relativistic formulation of the quark model recently proposed by Feynman, Kislinger, and Ravndal is applied to electroproduction of nucleonic resonances. Formulas for the ratio of longitudinal to transverse photoabsorption cross sections that are relevant to both the resonance and deep-inelastic regions are derived. This formulation is found to be much more successful than the nonrelativistic symmetric quark model and is consistent with the existing data.

Remarks on off shell ρ π sum rules and applications to π and K electromagnetic mass differences

The various current algebra sum rules for virtual isovector photons scattering on pions with I = 1,2 in the t-channel are studied with a view to saturation by the π, ω and A 1 intermediate states. A consistent set of ϱ dominated form factors are found which reproduce the strong coupling constants of Gilman and Harari. These form factors are used in a calculation of the π electromagnetic mass difference which automatically contains the current algebra result. Analogous form factors are chosen in a calculation of the K e.m. mass difference which includes a re-evaluation of the FESR for the high-energy A 2 contribution. Some remarks are also made about the relevance of the deep inelastic scaling region and it is shown how its contribution to the overall e.m. mass shift might be finite.

Measuring chiral symmetry breaking in neutrino scattering

The ideas of broken scale invariance and operator light cone expansions are used to relate the scale dimension of the chiral symmetry breaking part of the strong interaction Hamiltonian to the energy dependence of the form factors W 4 and W 5 in the deep inelastic region of neutrino scattering. The possibility that neutrino scattering may be used to measure the scale dimension of the chiral SU(3) ⊗ SU(3) breaking Hamiltonian is pointed out.

Inelastice−pScattering in Massive Quantum Electrodynamics

We calculate, in the deep-inelastic region, the leading contributions to $\ensuremath{\nu}{W}_{2}$ in each order of perturbation theory for quantum electrodynamics with massive photons. Scaling is broken by $\mathrm{ln}{Q}^{2}$ factors which come from both transverse and longitudinal phase-space integrations and which exponentiate in an elegant eikonal-like form. The important final states are characterized by a single "hard" proton and multiple "soft" meson production; $〈n〉\ensuremath{\sim}{\mathrm{ln}}^{2}{Q}^{2}$. There is an intimate relationship between the elastic form factor and the inelastic structure function $\ensuremath{\nu}{W}_{2}$. A Drell-Yan-West relation holds after a slight generalization to accommodate the logarithmic violation of scaling.

The Universality of the Family of Structure Functions

Our previous analyses of deep inelastic lepton-hadron collisions are re-examined in the vanishing limit of the Pomeron contribution. It will be shown that the universality of struc­ ture functions can be deduced from our basic postulates in this limit. A further extension of this result is discussed in connection with the conjectured existence of a single universal function. 2 > supple­ mented by the Pomeron contribution and the available ep-data. 3 > In particular, we have argued that the Pomeron plays only a minor role in these processes and consequently various observable quantities reflect the character of each target hadron according to the counting rule. Furthermore these are closely related to the concept of the universality of structure functions. As for the preliminary SLAC-data 4 > one-deuteron collisons, they clearly show the difference between ep- and en-processes, in qualitative agreement with our predictions. In this connection, we remark that the . SLAC-data is still limited to relatively low energy (v)- and momentum (q 2 )-transfer region and thus they cannot be regarded as those of the really deep inelastic region, a measure of this being discussed in the final section. It is interesting to note that the Pomeron contribution is rather small in this kinematic region, while it does dominate in low q 2 -region just as the case in high energy nucleon Compton total cross section. 5 > In view of these facts, we are tempted to consider the vanishing limit of the Pomeron contribution in the deep inelastic region. The purpose of _this note is to reconsider our analyses in this limit and to eliminate certain superfluous assumptions made in I. In fact it will be shown that the following form of the universality of structure functions is a direct con­ sequence of our approach, i.e., with the notation used in I,

Deep-Inelastic Neutrino Scattering in a Resonance Model

Deep-inelastic neutrino scattering is investigated in the framework of a direct-channel resonance model. Using empirical properties of the baryon spectrum and making a universality hypothesis for the transition form factors, we deduce that in the Bjorken limit the structure functions ${W}_{1}$, $\ensuremath{\nu}{W}_{2}$, and $\ensuremath{\nu}{W}_{3}$ become functions of the scale variable (ratio of center-of-mass energy to momentum transfer) alone. By imposing generalized Goldberger-Treiman-Nambu relations on the axial-vector transition matrix elements and fixing the coupling constants from low-energy experiments, we predict all structure functions without free parameters. The predictions of the theory are compared with neutrino scattering data obtained at CERN. Good agreement is found between theory and experiment in the deep-inelastic region.

Structure functions for inelastic proton-proton scattering at different energies

Present data for proton-proton interactions in the region from 6 to 30 GeV c show a strong energy dependence of the structure function defined for inelastic p-p scattering in the deep inelastic region. This contrasts with the behaviour of the structure function for inelastic electron-proton scattering.

Light cone and vector meson dominance in photo-and electroproduction

By using the formalism of mass dispersion relations and light cone dominance for large masses, relations are derived between photoproduction and deep inelastic electroproduction. In addition large deviations from VDM are derived for ϱ o electroproduction in the deep inelastic region; these results compare quite well with recent experimental information.

Hadron-hadron collisions in the deep inelastic region

Hadron-hadron collisions in the deep inelastic region

Regge Model with Scale-Invariance for Nucleon Compton Scattering, Electroproduction, and Electron-Positron Annihilation

A Regge model satisfying the requirement of scale invariance is constructed for the Compton amplitude. Using the $P$, ${P}^{\ensuremath{'}}$, and ${A}_{2}$ Regge trajectories, we obtain good fits to the total photon-nucleon cross sections and to the differential cross section $\frac{d\ensuremath{\sigma}}{\mathrm{dt}}$ for proton Compton scattering. The model is then applied to electroproduction in the deep-inelastic region and successfully describes the data on the proton and neutron structure functions, the breaking of scale invariance at small -${q}^{2}$ and the behavior of the ratio $\frac{{W}_{2}^{n}}{{W}_{2}^{p}}$, as a function of -${q}^{2}$ for fixed hadronic mass squared. Predictions are given for the differential cross section for the crossed-channel process ${e}^{+}+{e}^{\ensuremath{-}}\ensuremath{\rightarrow}\mathrm{proton}+\mathrm{hadrons}$, and it is found that for large ${q}^{2}$ the total annihilation cross section behaves as ${\ensuremath{\sigma}}_{T}\ensuremath{\approx}\frac{1}{{q}^{2}}$.

A current-algebra-like approach to the deep inelastic region.

The connection between scale-invariant structure functions of the electron-proton scattering in the deep inelastic region and charge-density commutators at almost equal time is discussed; current algebra features and methods turn out to be relevant in this framework and an infinite set of sum rules is derived. By exploiting the microcausality requirement, certain consequences of scaling amplitudes are obtained, which severely limit the analytical structure of the latter.

Extrapolation of the Structure Function νW2from the Deep Inelastic Region down to the Resonance Region ine-pScattering

Extrapolation of the Structure Function ν<i>W</i>₂from the Deep Inelastic Region down to the Resonance Region in<i>e</i>-<i>p</i>Scattering