Gross-Llewellyn Smith Sum Rule Research Articles

Nucleon structure functions from νμ-Fe scattering at the Tevatron

Preliminary measurements of structure functions have been made from a sample of 1,281,000 ν μ and 270,000 ν μ charged current events with 30 GeV < E ν < 600 GeV. These include a new value of the Gross-Llewellyn Smith Sum Rule, ∫(1/x)(xF 3)dx=2.66 ± .03 (stat) ± .08 (syst), the ratio of cross sections, σ( ν μ)/σ(ν μ) = .511 ± .002 ( stat) ± .005 ( syst) , and an analysis of the Q 2 evolution of xF 3.

Power corrections to Bjorken and Gross-Llewellyn Smith sum rules in QCD

Twist-four corrections to the first moment of structure functions for deep inelastic νp scattering are examined. In contrast to previous estimations we found them to be not small — roughly equal to the perturbative correction at Q 2 ∼ 1 GeV 2 and of the same sign. Three independent calculations of the dynamical 1 Q 2 correction are presented that are all consistent with each other to a ∼ 50% accuracy. They are within the QCD sum rules approach, the vector dominance approximation and the nonrelativistic quark model. A short discussion of 1 Q 4 effects is presented. Our conclusion is that they are of minor importance.

Q 2 dependence of the proton and neutron structure functions from neutrino and antineutrino scattering in deuterium

12,100 νD and 10,500\(\bar vD\) charged current interactions in deuterium measured in the BEBC bubble chamber were used to obtain the complete set of structure functions of proton and neutron. Thex andQ2 dependence of the structure functions of up and down valence quarks and antiquarks are presented and discussed. The Adler and Gross-Llewellyn Smith sum rules have been tested at differentQ2 values. A QCD analysis of the four non singlet structure functionsxF3νN,xuv,xdv andF2νn−F2νp has been performed yielding values ofΛLO between 100 and 300 MeV.

Data on the Gross-Llewellyn Smith Sum Rule as a Function ofq2

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 q/sup 2/< or approx. =1 GeV/sup 2/. Limits on the effective QCD scale parameter ..lambda.. and on the magnitude of the twist-4 correction are set. The best fit, neglecting higher-twist contributions, gives ..lambda.. = 92/sub -/36/sup +20/ MeV.

Testing the Adler and Gross-Llewellyn Smith Sum Rules in High-Energy Neutrino Reactions

BS>A practical method of testng the Adler and Gross-Llewellyn Smith sum rules with high-energy neutrino beams is outlined. The test is found to rely only on a knowledge of the relative neutrino and antineutrino fluxes and does not require point-by-point knowledge of the F2 and F3 structurc functions. This test does rely on the assump tion that Bjorken scaling is satisified.

Scaling laws in high-energy neutrino reactions

Bjorken has proposed that the structure functionsF1,F2,F3 of deep inelastic neutrino scattering are functions of ω=−2Mν/q2 only. These scaling laws are studied in Veneziano-like models and are found to emerge naturally for the scattering of neutrinos on a neutron or of antineutrinos on a proton, together with the Callan-Gross sum rule for\(\int\limits_1^\infty d \omega F_2 /\omega ^2 \), the Gross-Llewellyn Smith sum rule for\(\int\limits_1^\infty d \omega F_3 /\omega ^2 \) and the relationF1=1/2ωF2. (It is assumed that certain equal-time commutators of currents contain no operator Schwinger terms). The models suggest the possibility that the structure functions for the scattering of neutrinos on a proton, or of antineutrinos on a neutron, are small in the deep inelastic limit.