| 1. |
- Aamodt, K., et al.
(författare)
-
Alignment of the ALICE Inner Tracking System with cosmic-ray tracks
- 2010
-
Ingår i: Journal of Instrumentation. - 1748-0221. ; 5
-
Konferensbidrag (refereegranskat)abstract
- ALICE (A Large Ion Collider Experiment) is the LHC (Large Hadron Collider) experiment devoted to investigating the strongly interacting matter created in nucleus-nucleus collisions at the LHC energies. The ALICE ITS, Inner Tracking System, consists of six cylindrical layers of silicon detectors with three different technologies; in the outward direction: two layers of pixel detectors, two layers each of drift, and strip detectors. The number of parameters to be determined in the spatial alignment of the 2198 sensor modules of the ITS is about 13,000. The target alignment precision is well below 10 mu m in some cases (pixels). The sources of alignment information include survey measurements, and the reconstructed tracks from cosmic rays and from proton-proton collisions. The main track-based alignment method uses the Millepede global approach. An iterative local method was developed and used as well. We present the results obtained for the ITS alignment using about 10(5) charged tracks from cosmic rays that have been collected during summer 2008, with the ALICE solenoidal magnet switched off.
|
|
| 2. |
- Acharya, S., et al.
(författare)
-
Antihelium-3 fluxes near Earth using data-driven estimates for annihilation cross section
- 2022
-
Ingår i: 37th International Cosmic Ray Conference (ICRC2021) - GAI - Gamma Ray Indirect. - Trieste, Italy : Sissa Medialab. - 1824-8039. ; 395
-
Konferensbidrag (refereegranskat)abstract
- Antinuclei found in cosmic rays could provide a smoking gun signal for dark matter as this signal is virtually background free. The study of 3He cosmic rays requires the knowledge of their production, propagation in the galaxy and annihilation cross-section. While the former two have been already estimated with data-driven methods, there were no experimental data available for the 3He inelastic cross section. We measured for the first time the inelastic cross section of 3He using the ALICE detector itself as a target. To study the effect of 3He annihilation in the galaxy and estimate the transparency of the galaxy, the 3He source functions and annihilation cross sections were implemented in GALPROP. © Copyright owned by the author(s) under the terms of the Creative Commons.
|
|
| 3. |
- Acharya, S., et al.
(författare)
-
Extending the ALICE strong-interaction studies to nuclei: measurement of proton-deuteron correlations in pp collisions at √s = 13 TeV
- 2022
-
Ingår i: The European Physical Society Conference on High Energy Physics. - Trieste, Italy : Sissa Medialab. - 1824-8039. ; 398
-
Konferensbidrag (refereegranskat)abstract
- The large data sample of high-multiplicity pp collisions collected by ALICE allows for the precise measurement of the size of source producing primary hadrons, opening the doors to a study of the interaction of different hadron species using femtoscopy techniques. The momentum correlation between (anti)protons and (anti)deuterons measured in pp collisions at √s = 13 TeV with ALICE is studied here for the first time. The measured correlation function for ((equation presented))p-((equation presented))d pairs is compared with theoretical predictions obtained considering Coulomb and Coulomb plus strong interactions and employing the Lednický-Lyuboshitz model with scattering parameters extracted from traditional scattering experiments for the p-d system. The measured correlation function can not be reproduced by any of the obtained predictions. This deviation can to large extent be interpreted as a demonstration of the late formation time of (anti)deuterons in hadron-hadron collisions. This observation is key for the understanding of the production mechanism of light (anti)nuclei, which is an open issue in high-energy physics and has also important consequences for the study of antinuclei formation in the interstellar medium either from collisions triggered by high-energy cosmic rays or by dark matter decays. © Copyright owned by the author(s) under the terms of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License (CC BY-NC-ND 4.0)
|
|
