Deep Inelastic Cross Sections Research Articles

Analysis of continuous spectra of the reactions ( 20Ne, 16O) and ( 20Ne, 12C) in terms of multi-step direct reaction theory

A multi-step direct reaction theory, which is completely quantum mechanical, is applied to analyze the deep inelastic cross sections of the ( 20Ne, 16O) and ( 20Ne, 12C) reactions. Possible extension of this method to more complicated cases is also discussed.

Deep-inelastic neutral-current cross sections

We derive expressions for deep-inelastic neutral-current cross sections in terms of charged-current cross sections and the first moment of electroproduction structure functions. We assume a general class of gauge models and the parton model, but no details of the parton distributions. The result is useful for examining the structure of right-handed particle multiplets.

On the general form of the cross section of deep inelastic collisions

The general form of the energy-averaged “macroscopic” cross section for deep inelastic (DI) collisions is derived on the basis of semiclassical approximations. The amplitude for DI reactions is related to the incompletely relaxed part of the fluctuating S-matrix. The possibility of diffraction effects modifying the DI cross section is investigated. In the limit of a classical treatment of the external variables, the average DI cross section is shown to be uniquely determined by a classical distribution function.

Neutral current parity violation and gauge flavours

In a large class of gauge theories the trace of the weak neutral axial charge operator over any complete irreducible gauge multiplet is shown to vanish. This implies a relation involving deep inelastic neutrino-induced neutral current parity-violating cross sections which can be used to test the correctness of the Weinberg-Salam gauge multiplet structure of quarks.

Deep inelastic collisions: A classical description with friction and deformation

A simple classical model with frictional forces and deformation degrees of freedom is presented which reproduces the deep inelastic cross sections, angular distributions and energy losses in a wide range of nuclei. A quantitative fit to the fusion cross sections can also be obtained.

Polarized deep inelastic sum rules

New sum-rules for the polarized deep inelastic neutrino-nucleon cross sections are derived by applying the Melosh transformation to matrix elements of local currents and of local limits of the first derivatives of bilocal currents.

General approach to deep inelastic scattering

Due to preliminary indications of a possible scaling violation, it is interesting to clarify which of the parton light-cone results are indeed the consequences of a more general scheme. We consider the constraints imposed by the general ideas of duality (absence of exotics in the t-channel) applied to deep inelastic single-particle distributions. This provides a restrictive scheme, although it allows for a larger set of diagrams than that of the parton model. However, in a particular kinematical region where the diffractive component of the total deep inelastic cross section can be neglected, all the algebraic results of the parton model are recovered by this scheme.

Contributions of vector-meson dominance to charmed-meson production in inelastic neutrino and antineutrino interactions

We discuss the contribution to neutrino-hadron interaction due to ${F}^{*}$ dominance of the weak vector current, and we give quantitative estimates of the $x$ and $y$ distributions for the deep-inelastic cross section at various energies. Other contributions, such as the nonresonant continuum and axial-vector terms, have been qualitatively discussed as well. We compare our results with experimental data on single-muon and dimuon production. We also calculate the diffractive, "elastic" ${F}^{*}$ production cross section.

Effects of charm and colour in deep inelastic neutrino scattering

We investigate possible effects of the charm quantum number and colour degree of freedom on deep inelastic neutrino (and electron) scattering in a twelve-quark-parton model. The weak and the electromagnetic currents which belong to theSU2⊗U1 gauge group are constructed appropriately in a generalized GIM scheme. It is found that the deep inelastic cross-sections increase only by about 10% above the charm threshold, while above the colour threshold they become about 1.7 times as large as those below the colour threshold. The ratiosR,\(\bar R\)andRcremain almost unchanged at the charm and the colour thresholds.

Gauge theories and neutral currents

We consider neutral current effects in some gauge theoretic models of weak and electromagnetic interactions. Asymptotic invariance under the gauge group is proposed and used for estimating deep-inelastic cross sections. Our analysis underlines the need for a systematic search for hadronic threshold effects in the coupling of neutral currents.

On the azimuthal dependence of semi-inclusive, deep inelastic electroproduction cross sections

It is pointed out that according to the parton model, there should be no dependence on the azimuthal angle in the cross section for deep inelastic, semi-inclusive electroproduction with one detected hadron in the final state.

Scattering of light by light using electron-positron colliding beams

We discuss the process e−+e+→γ+hadrons. Using automodelity, vectorsmeson dominance and the parton model, we give an estimate of the deep-inelastic cross section, showing that it might be comparable to the cross section of the deep-inelastic reaction e−+e+→H+anything H being a singled-out hadron. Some of the one-meson contributions are calculated in the quark model.

Deep inelastic electron scattering in perturbation theory

Deep inelastic ep scattering and deep inelastic annihilation cross sections have been found in vector and pseudo-scalar meson theories assuming the coupling constant g 2⪡1, but g 2 ln q 2∼1. It is shown that in a vector theory, despite a rapid drop of electromagnetic form factors, the ep deep inelastic scattering amplitudes increase with q 2 at fixed ω.

A parton theory based on the dual resonance model

We consider the consequences of replacing the continuous string model of hadrons by an infinite but discrete chain of partons. It is shown that such a replacement leads to a sensible theory of form factors and deep inelastic electro-production cross sections. Experimental data concerning these quantities are used to estimate the departure from the continuum limit. We find that a hadron is probably a fairly loosely knit structure.