| 1. |
- Fjelstad, Jens, 1971-, et al.
(författare)
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Equivalence of Chern-Simons gauge theory and WZNW model using a BRST symmetry
- 1999
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Ingår i: Physics Letters B. - : Elsevier. - 0370-2693 .- 1873-2445. ; 466:2-4, s. 227-233
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Tidskriftsartikel (refereegranskat)abstract
- The equivalence between the Chern-Simons gauge theory on a three-dimensional manifold with boundary and the WZNW model on the boundary is established in a simple and general way using the BRST symmetry. Our approach is based on restoring gauge invariance of the Chern-Simons theory in the presence of a boundary. This gives a correspondence to the WZNW model that does not require solving any constraints, fixing the gauge or specifying boundary conditions.
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| 2. |
- Allasia, D, et al.
(författare)
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Inelastic J ψ production in deep inelastic scattering from hydrogen and deuterium and the gluon distribution of free nucleons
- 1991
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Ingår i: Physics Letters B. - : Elsevier. - 0370-2693 .- 1873-2445. ; 258:3-4, s. 493-498
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Tidskriftsartikel (refereegranskat)abstract
- We present results on inelastic J/PSI-production from muon interactions with hydrogen and deuterium at an incident muon energy of 280 GeV. The measured cross section ratio per nucleon for muon-induced J/PSI-production in deuterium and hydrogen was found to be R(D2/H2) = 1.01 +/- 0.15. The colour singlet model is shown to provide a good description of the observed differential cross section apart from a normalisation factor. The comparison between the observed cross section and the colour singlet model prediction allows the extraction of the gluon structure function G(chi) of the nucleon. The momentum fraction-chi of the nucleon carried by the gluon is measured in the range of chi = [0.02, 0.30]. The normalised gluon distribution of free nucleons thus found can be parametrised as chi-G(chi) = 1/2 (eta + 1)(1 - chi)eta, with eta = 5.1 +/- 0.9 (stat).
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| 3. |
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| 4. |
- Amaudruz, P, et al.
(författare)
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Measurements of Rd-Rp and RCa-Rc in deep inelastic muon scattering
- 1992
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Ingår i: Physics Letters B. - : Elsevier. - 0370-2693 .- 1873-2445. ; 294:1, s. 120-126
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Tidskriftsartikel (refereegranskat)abstract
- Results are presented on the difference in R, the ratio of longitudinally to transversely polarised virtual photon absorption cross sections, for the deuteron and the proton. They are obtained by comparing the ratio of cross sections for the deep inelastic scattering of muons from deuterium and hydrogen targets at 90 and 280 GeV incident energy. The results cover the range x = 0.01 -0.30, at an average Q2 of 9 GeV2. The measured difference R(d)-R(p) shows no significant x dependence and is compatible with zero, as well as with expectations from perturbative QCD. We use the same method to obtain the difference R(Ca)-R(C) from cross section ratios measured on carbon and calcium targets at 90 and 200 GeV incident energy.
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| 5. |
- Amaudruz, P, et al.
(författare)
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Proton and deuteron F2 structure functions in deep inelastic muon scattering
- 1992
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Ingår i: Physics Letters B. - : Elsevier. - 0370-2693 .- 1873-2445. ; 295:1-2, s. 159-168
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Tidskriftsartikel (refereegranskat)abstract
- The structure functions F2p and F2d measured by deep inelastic muon scattering at incident energies of 90 and 280 GeV are presented. These measurements cover a large kinematic range, 0.006 less-than-or-equal-to x less-than-or-equal-to 0.6 and 0.5 less-than-or-equal-to Q2 less-than-or-equal-to 55 GeV2, and include the first precise data at small x, where large scaling violations are observed. The data agree with earlier results from SLAC and BCDMS but exhibit differences with respect to those of EMC-NA2. Extrapolations to small x of recent phenomenological parton distributions are shown to disagree with the present results.
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| 6. |
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| 7. |
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