| 41. |
- Calén, H, et al.
(författare)
-
Deuteron breakup in the Δ-isobar region
- 1993
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Ingår i: Physica Scripta. - : Institute of Physics (IOP). - 0031-8949 .- 1402-4896. ; 48:1, s. 86-91
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Tidskriftsartikel (refereegranskat)abstract
- The pd → npp charge exchange reaction has been studied at 1.15 GeV incident proton energy in a selected kinematical region. The distributions of two-proton invariant mass Mpp, of angle of a single proton and the differential cross section dσ/dt of the (p, n) reaction are presented and compared with model predictions corrected for the acceptance of the experimental apparatus. We see no evidence of narrow (Γ < 30 MeV/c2) peaks in the Mpp interval 2.1-2.3 GeV/c2. The production of an intermediate Δ isobar in the primary (p, n) charge exchange and its subsequent absorption in a final state ΔN → pp process together with the background from quasi-free charge exchange scattering reasonably reproduces the general trends of the data.
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| 42. |
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| 43. |
- Calén, H, et al.
(författare)
-
Measurement of the quasifree p+n->d+eta reaction near threshold
- 1997
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Ingår i: PHYSICAL REVIEW LETTERS. - : AMER INST PHYSICS. - 0031-9007. ; 79:14, s. 2642-2645
-
Tidskriftsartikel (refereegranskat)abstract
- The quasifree p + n --> d + eta reaction cross section has been measured in the near-threshold region using deuterium from an internal cluster-jet target and 1350 MeV protons in the CELSIUS storage ring of the The Svedberg Laboratory, Uppsala. The energy
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| 44. |
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| 45. |
- Calén, H., et al.
(författare)
-
The pp → ppη reaction near the kinematical threshold
- 1996
-
Ingår i: Physics Letters B. - : Elsevier. - 0370-2693 .- 1873-2445. ; 366:1-4, s. 39-43
-
Tidskriftsartikel (refereegranskat)abstract
- The pp → ppη reaction has been measured at six energies close to threshold, from 1258 MeV to 1352 MeV, using an internal cluster gas jet target in the CELSIUS storage ring. The η is detected through its decay photons, in an array of CsI detectors, and the forward-going protons are detected in a plastic scintillator spectrometer. A complete event reconstruction is obtained at the higher energies in the measured interval. The new data, together with earlier data, give an accurate determination of the energy dependence close to threshold. The influence of the η-proton FSI is seen in the total cross section data as well as in a Dalitz plot of the η-p invariant mass distributions.
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| 46. |
- Calén, H, et al.
(författare)
-
Upper limits for a narrow dibaryon in pp collisions at 200 and 310 MeV
- 1998
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Ingår i: PHYSICS LETTERS B. - : ELSEVIER SCIENCE BV. - 0370-2693. ; 427:3-4, s. 248-253
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Tidskriftsartikel (refereegranskat)abstract
- Dibaryons, forbidden by mass to decay into NN pi channel and by quantum numbers into NN channel, may still have escaped detection. In fact, recently an observation of a narrow dibaryon (D) with the mass close to 1920 MeV was reported in the process pp -->
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| 47. |
- Clement, H, et al.
(författare)
-
Search for narrow NN-decoupled resonances in the pi NN-system - An overview
- 1996
-
Ingår i: PROGRESS IN PARTICLE AND NUCLEAR PHYSICS. - : PERGAMON PRESS LTD. ; , s. 369-378
-
Konferensbidrag (refereegranskat)abstract
- The status of the search for NN-decoupled resonances in the pi NN-system is reviewed. After a short survey on the history of dibaryon searches reactions suitable for detecting such resonances are discussed. Special emphasis is put on the pionic double cha
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| 48. |
- Clement, H., et al.
(författare)
-
Search for narrow NN-decoupled resonances in the πNN-system : An overview
- 1996
-
Ingår i: Progress in Particle and Nuclear Physics. - : Elsevier BV. - 0146-6410 .- 1873-2224. ; 36, s. 369-378
-
Tidskriftsartikel (refereegranskat)abstract
- The status of the search for NN-decoupled resonances in the πNN-system is reviewed. After a short survey on the history of dibaryon searches reactions suitable for detecting such resonances are discussed. Special emphasis is put on the pionic double charge exchange, where recently evidence for the signature of a narrow πNN resonance, called d′, with I(J P) = even (0 -) and m = 2.06 GeV has been quoted. Further reactions discussed in this context are the pion photoproduction on the deuteron and the two-pion production in nucleon-nucleon collisions.
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| 49. |
- Hakansson, M C, et al.
(författare)
-
The electronic structure of In- and As-terminated InAs(001) surfaces
- 1997
-
Ingår i: Surface Science. - 0039-6028 .- 1879-2758. ; 374:1-3, s. 73-79
-
Tidskriftsartikel (refereegranskat)abstract
- The InAs(001) 2 x 4 and 4 x 2 surfaces have been investigated by angle-resolved photoemission. The X(3) and X(5) points were found to be located 6.0 and 2.7 eV below the valence band maximum, respectively, and the dispersion of bulk bands along the Gamma-X direction in the bulk Brillouin zone were well described by a theoretical calculation. From angle-resolved valence band spectra measured along the high symmetry directions [110] and [1(1) over bar0$], three surface induced stares were identified on both the InAs(001)4 x 2 and the InAs(001)2 x 4 surface. (C) 1997 Elsevier Science B.V.
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| 50. |
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