We present results on the experimental study of inelastic charged-current antineutrino-nucleon scattering in the energy range of 10–200 GeV. The data sample, consisting of about 6500 antineutrino-induced events, was obtained in the Fermilab 15 ft bubble chamber filled with a heavy neon-hydrogen mixture. The differential cross sections for ν μ N interactions are presented in terms of scaling variables x and y . The structure functions F 2 ν and xF 3 ν have been evaluated as functions of x and E ν . A deviation from the scaling hypothesis, similar to those found in other experiments on inelastic lepton-nucleon scattering, has been observed. The data are interpreted in the framework of the quark-parton model. Quark and antiquark distributions and their energy dependences are presented.
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Using data taken at PETRA we present results on deep inelastic electron photon scattering at momentum transfers 1 < Q 2 < 15 GeV 2 . The results are expressed in terms of the photon structure function F 2 and are compared with QCD predictions and “hadronic” models of the photon. The pointlike component of the photon is found to be dominant.
Data read from graph.. Data for W < 3.5 in Berger et al. 1981, PL 99B,287 (<a href=http://durpdg.dur.ac.uk/scripts/reacsearch.csh/TESTREAC/red+1164> RED = 1164 </a>).
PHOTON STRUCTURE FUNCTION. NUMERICAL VALUES OF DATA ON FIGURE SUPPLIED BY W. WAGNER.
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We present a measurement of the hadronic structure function F 2 γ ( x , Q 2 ) of the photon in the Q 2 range from 10 to 100 GeV 2 . Data were taken with the PLUTO detector at the e + e - storage ring PETRA. This measurement and previous PLUTO measurements in the Q 2 range of 1.5 to 16 GeV 2 are compared with higher order QCD calculations. The structure function is consistent with the predicted log Q 2 behaviour when charm contributions are subtracted. The x dependence can be well described for 0.1 < x < 0.9 by the regularization scheme of Antoniadis and Grunberg. Within their scheme the data yield a value of Λ MS = 183 + 65/ −40( stat. ) + 46/ −36( sys. ) MeV for the QCD scale parameter.
Data read from graph.
Data read from graph.
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This paper presents our first measurement of the F 2 structure function in neutral-current, deep inelastic scattering using the ZEUS detector at HERA, the ep colliding beam facility at DESY. The data correspond to an integrated luminosity of 24.7 nb −1 . Results are presented for data in range of Q 2 from 10 GeV 2 to 4700 GeV 2 and Bjorken x down to 3.0 × 10 −4 . The F 2 structure function increases rapidly as x decreases.
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A measurement of the proton structure function F 2 ( x , Q 2 ) is presented with about 1000 neutral current deep inelastic scattering events for Bjorken x in the range x ⋍ 10 −2 – 10 −4 and Q 2 > 5 GeV 2 . The measurement is based on an integrated luminosity of 22.5 nb −1 recorded by the H1 detector in the first year of HERA operation. The structure function F 2 ( x , Q 2 ) shows a significant rise with decreasing x .
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We present measurements of the hadronic photon structure functionF2γ(x), in twoQ2 ranges with mean values of 5.9 GeV2 and 14.7 GeV2. The data were taken by the OPAL experiment at LEP, with\(\sqrt s\) close to theZ0 mass and correspond to an integratede+e− luminosity of 44.8 pb−1. In the context of a QCD-based model we find the quark transverse momentum cutoff separating the vector meson dominance (VMD) and perturbative QCD regions to be 0.27±0.10 GeV. We confirm that there is a significant pointlike component of the photon when the probe photon hasQ2>4 GeV2. Our measurements extend to lower values ofx than any previous experiment, and no increase ofF2γ(x) is observed.
Additional overall systematic error 5.9% not included.
Additional overall systematic error 5.9% not included.
The ZEUS detector has been used to measure the proton structure functionF2. During 1993 HERA collided 26.7 GeV electrons on 820 GeV protons. The data sample corresponds to an integrated luminosity of 0.54 pb−1, representing a twenty fold increase in statistics compared to that of 1992. Results are presented for 7<Q2<104 GeV2 andx values as low as 3×10−4. The rapid rise inF2 asx decreases observed previously is now studied in greater detail and persists forQ2 values up to 500 GeV2.
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The gluon momentum density xg ( x , Q 2 ) of the proton was extracted at Q 2 = 20 GeV 2 for small values of x between 4 × 10 −4 and 10 −2 from the scaling violations of the proton structure function F 2 measured recently by ZEUS in deep inelastic neutral current ep scattering at HERA. The extraction was performed in two ways. Firstly, using a global NLO fit to the ZEUS data on F 2 at low x constrained by measurementsfrom NMC at larger x ; and secondly using published approximate methods for the solution of the GLAP QCD evolution equations. Consistent results are obtained. A substantial increase of the gluon density is found at small x in comparison with the NMC result obtained at larger values of x .
Values of F2 and slope of F2 obtained from fits to the ZEUS paper used in the extraction of the gluon momentum distributions.
Gluon momenta distribution at Q**2 = 20.
A measurement of the proton structure function $F_{\!2}(x,Q~2)$ is reported for momentum transfer squared $Q~2$ between 4.5 $GeV~2$ and 1600 $GeV~2$ and for Bjorken $x$ between $1.8\cdot10~{-4}$ and 0.13 using data collected by the HERA experiment H1 in 1993. It is observed that $F_{\!2}$ increases significantly with decreasing $x$, confirming our previous measurement made with one tenth of the data available in this analysis. The $Q~2$ dependence is approximately logarithmic over the full kinematic range covered. The subsample of deep inelastic events with a large pseudo-rapidity gap in the hadronic energy flow close to the proton remnant is used to measure the "diffractive" contribution to $F_{\!2}$.
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