| 1. |
- Adiels, L., et al.
(författare)
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Search for narrow exotic states in annihilations on 4He
- 1984
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Ingår i: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 138:1-3, s. 235-240
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Tidskriftsartikel (refereegranskat)abstract
- After having found evidence for narrow exotic states in p annihilation, the production of such states on a nuclear target was studied with similar techniques. The γ spectrum associated with annihilation on 4He at rest was measured. The spectrum shows two peaks, at energies of 161.9 and 203.0 MeV, corresponding to intermediate narrow states of masses which seem to be related to states found in p annihilations. The confidence is better than 4 σ.
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| 2. |
- Adiels, L., et al.
(författare)
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Search for narrow signals in the [gamma]-spectrum from [Proton-antiproton] annihilation at rest
- 1986
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Ingår i: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 182:3-4, s. 405-408
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Tidskriftsartikel (refereegranskat)abstract
- The [gamma]-spectrum originating from pp[combining macron] annihilations at rest in liquid hydrogen was measured with two BGO spectrometers. A total of 24 ï¿œ 106[gamma]’s were accumulated. No narrow peaks indicating exotic states such as baryonium were observed. The upper limit for the branching ratio with 1040 [less-than-or-equals, slant] mx [less-than-or-equals, slant] 1770 MeV/c2 and with [lambda]x [less-than-or-equals, slant] 25 MeV/c2 is less than 10-3 with more than 99.96% confidence.
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| 3. |
- Adiels, L., et al.
(författare)
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Search for narrow signals in the γ-spectrum from pp̄ annihilation at rest
- 1986
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Ingår i: Physics Letters B. - : Elsevier. - 0370-2693 .- 1873-2445. ; 182:3-4, s. 405-408
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Tidskriftsartikel (refereegranskat)abstract
- The γ-spectrum originating from pp̄ annihilations at rest in liquid hydrogen was measured with two BGO spectrometers. A total of 24 × 10 6 γ's were accumulated. No narrow peaks indicating exotic states such as baryonium were observed. The upper limit for the branching ratio p p ̄ → γ + X with 1040 ≤ m x ≤ 1770 MeV/c 2 and with λ x ≤ 25 MeV/c 2 is less than 10 -3 with more than 99.96% confidence. © 1986.
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| 4. |
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| 5. |
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| 6. |
- Ekelin, Svante, et al.
(författare)
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Large-pT protons from constituent diquark scattering
- 1984
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Ingår i: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 149:6, s. 509-513
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Tidskriftsartikel (refereegranskat)abstract
- Recent data from the CERN ISR on the fractional proton yield in pp collisions are explained within the Stockholm diquark model. Describing the proton as a u(ud)0 system, the observed high magnitude and fall-off pT, θ and √s of the proton yield are natural consequences of constituent diquark elastic scattering. The pT and θ dependence favour a value of around 10 GeV2/c2 for the size parameter in the diquark form factor, corresponding to a diquark rms radius of around 0.2 fm. This is consistent with earlier results of the model applied to deep inelastic lepton-nucleon scattering and e+e- annihilation
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| 7. |
- Fredriksson, Sverker, et al.
(författare)
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New ideas on the proton-neutron differences in deep inelastic structure functions
- 1985
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Ingår i: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 162:4-6, s. 373-378
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Tidskriftsartikel (refereegranskat)abstract
- It is shown how future data from deep inelastic scattering of charged leptons on protons and neutrons can be used to discriminate between the two main possible scale-breaking QCD effects - perturbative gluon processes and non-perturbative diquark formation. Current data from the Stanford Linear Accelerator Center and from CERN on the structure function combinations Fp2-Fn2, Fn2/Fp2 and σL/σT are in line with both the Stockholm diquark model and perturbative QCD, considering the low statistics as well as the possibility of a substantial normalisation error between the two data sets. This calls for a new high-statistics experiment on a deuterium target before any definite conclusions can be made.
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| 8. |
- Guigas, R., et al.
(författare)
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Strong interaction effects in antiprotonic 6Li/7Li atoms
- 1984
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Ingår i: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 137:56, s. 323-328
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Tidskriftsartikel (refereegranskat)abstract
- The effects of strong interaction on the 3 –> 2 X-ray transition in antiprotonic 6Li/7Li atoms have been measured at the low energy -beam at CERN. For the shifts and widths of the levels the values [epsilon]2p = (-230 ï¿œ 72) eV, [Gamma]2p = (443 ï¿œ 210) eV, and [Gamma]3d = (0.130 ï¿œ 0.045) eV for 6Li, and [epsilon]2p = (-336 ï¿œ 60) eV, [Gamma]2p = (456 ï¿œ 190) eV, and [Gamma]3d = (0.210 ï¿œ 0.062) eV for 7Li were found. The data are compared with optical model predictions.
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| 9. |
- Köhler, Th., et al.
(författare)
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Precision measurement of strong interaction isotope effects in antiprotonic 16O, 17O, and 18O atoms
- 1986
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Ingår i: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 176:3-4, s. 327-333
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Tidskriftsartikel (refereegranskat)abstract
- The strong-interaction effects in antiprotonic 16O, 17O, and 18O atoms were measured at the CERN antiproton facility, LEAR. The shifts ε{lunate} and the widths Γ of the 3d level were determined to be -112±20 eV (16O), -140±46 eV (17O), -195±20 eV (18O), and 495±45 eV (16O), 540±150 (17O), 640±40 eV (18O), respectively. © 1986.
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| 10. |
- Richter, B., et al.
(författare)
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New results in the search for narrow states in the p system below threshold
- 1983
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Ingår i: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 126:3-4, s. 284-288
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Tidskriftsartikel (refereegranskat)abstract
- The γ-ray spectrum after p annihilation at rest was measured in two independent high-statistics runs. Both spectra show narrow peaks, corresponding to masses of 1210, 1638, 1694 and 1771 MeV.
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