Data are presented on the Gross-Llewellyn Smith sum rule obtained from combined narrow-band neon and Freon bubble-chamber neutrino-antineutrino experiments. Remarkably no significant deviation from the parton-model prediction for the sum rule is observed at very low values of q2≲1 GeV2. Limits on the effective QCD scale parameter Λ and on the magnitude of the twist-4 correction are set. The best fit, neglecting higher-twist contributions, gives Λ=92−36+20 MeV.
NACHTMANN MOMENT IS EVALUATED (IE TARGET MASS COEERCTIONS INCLUDED).
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The energy dependence of the transverse momentum invariant distribution of pions and neutral kaons is studied in K − p interactions between 14.3 and 70 GeV/ c . The large P T part of the distributions violates the Feynman scaling and, above P T ≃ 1.5 GeV/ c , appears to be reasonably described by hard scattering models. The variation of the average transverse momentum is also studied as a function of the c.m. reduced longitudinal momentum, and its behaviour is compared to the data obtained via the hadronic shower produced in lepton-hadron interactions.
HERE K0 MEANS K0 OR AK0 I.E. K(NEUTRAL).
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The study of π ± , π 0 , K 0 and Λ production in the fragmentation regions (| x |0.2) of K − p interactions at 70 GeV/ c shows that the x -dependence of each invariant cross section is well described by the power law (1−| x |) n suggested by the dimensional counting rule. Furthermore, pion production is found, both in K − and proton fragmentation regions, to be very similar to their production in ν( ν ) p interactions as expected from quark-parton models. The quark and diquark fragmentation functions D u π , D uu π and D ud π are extracted from our data.
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High energy factorization predictions for F2^c are derived using BFKL descriptions of the proton structure function F2 at HERA. The model parameters are fixed by a fit of F2 at small x. Two different approaches of the non perturbative proton input are shown to correspond to the factorization at the gluon or quark level, respectively. The predictions for F2^c are in agreement with the data within the present error bars. However, the photon wave-function formulation (factorization at quark level) predicts significantly higher F2^c than both gluon factorization and a next-leading order DGLAP model.
Axis error includes +- 0.0/0.0 contribution (DUE TO BACKGROUND SUBTRACTION, FINITE GEOMETRY EFFECTS AND MULTIPLE SCATTERING//A NORMALIZATION UNCERTAINTY OF 0.015 FOR THE POLARIZATION OF THE INCIDENT NEUTRONS IS NOT INCLUDED).
Taking into account the structure of the proton in a very simple way, we find the energy levels and the wave functions for the bound states of a proton in the field of an Abelian magnetic pole, confirming the enhancement of the Rubakov effect.
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We have studied muon-produced hadrons from a deuterium target. The structure functions and the charge ratios are reported for neutrons; the transverse momentum and azimuthal distributions are reported for deuterons. The structure function for the neutron is similar to that of the proton. The charge ratio of produced hadrons follows the expectation of a simple spin-½ quark model. Transverse-momentum results agree with those at lower energy and are similar to those from hadron-hadron interactions. No azimuthal anisotropy is seen.
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New formulae for constructing the pion photoproduction amplitude J from experimental data are presented. The phase of J is expressed in terms of its zeroes in the energy plane, the particle poles and a dispersion integral over the modulus of J , the latter being given, except for a finite unphysical interval, in terms of differential cross sections and recoil nucleon polarizations. For γ p→ π + n at t ≈−0.870 μ 2 , where the unphysical-region contribution vanishes, the zeroes are found approximately, so that the phase of J can be uniquely determined from the experimental data.
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The differential cross section of K − p and K + p elastic scattering has been measured at 4.2, 7 and 10 GeV/ c in the very forward region of scattering angles. The measurements have been made at the CERN PS by means of multiwire proportional chambers and counters. The region of momentum transfers t is 0.001 ⩽ | t | ⩽ 0.10 GeV 2 at the highest momentum and 0.001 ⩽ | t | ⩽ 0.03 GeV 2 at the lowest. Over these regions the Coulomb and the nuclear amplitudes reach their maximum interference. We have used a parametrisation of the above amplitudes to determine the value of the real part of the nuclear forward scattering amplitude. A dispersion relation fit has then been performed using these and earlier measurements; the asymptotic behaviour of the K ± p real parts has been examined in the light of this fit.
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