Refine
Language
- English (23)
Has Fulltext
- yes (23)
Is part of the Bibliography
- no (23)
Keywords
- LHC (6)
- ALICE (3)
- ALICE experiment (2)
- pp collisions (2)
- 900 GeV (1)
- Beauty production (1)
- Comparison with QCD (1)
- Electron-pion identification (1)
- Femtoscopy (1)
- Fibre/foam sandwich radiator (1)
Institute
- Physik (23)
- Frankfurt Institute for Advanced Studies (FIAS) (20)
- Informatik (20)
The Transition Radiation Detector (TRD) was designed and built to enhance the capabilities of the ALICE detector at the Large Hadron Collider (LHC). While aimed at providing electron identification and triggering, the TRD also contributes significantly to the track reconstruction and calibration in the central barrel of ALICE. In this paper the design, construction, operation, and performance of this detector are discussed. A pion rejection factor of up to 410 is achieved at a momentum of 1 GeV/c in p–Pb collisions and the resolution at high transverse momentum improves by about 40% when including the TRD information in track reconstruction. The triggering capability is demonstrated both for jet, light nuclei, and electron selection.
The elastic alpha scattering to backward angles has been studied for 40,42,44,48Ca between 40.7 and 72.3 MeV. The cross sections for 40Ca are larger than those for the higher isotopes up to the highest energies. They show backward increases that disappear above 50 MeV. The enhancement factor for 40Ca over 42,44Ca varies smoothly with energy. 48Ca does also show a backward cross-section enhancement over 42,44Ca. alpha -cluster rotational bands in the 44Ti compound state, four-nucleon correlations in 40Ca, and the l-dependent optical model are discussed as approaches to understand the anomaly. The rotator model appears to agree qualitatively with the experimental data. It involves rotational bands extending at least up to J=16 in 44Ti.
Back-angle enhancements of elastic alpha -scattering cross sections have been observed for nuclei at the ends of the 1p, 2s-1d, and f7 / 2 shells. Strong reduction of this enhancement occurs if excess neutrons enter the next open major shell. The results are discussed in terms of intermediate alpha structure.