Data-driven precision determination of the material budget in ALICE

0582692 - ÚJF 2024 RIV US eng J - Journal Article
Acharya, S. - Adamová, Dagmar - Adler, A. - Aglieri Rinella, G. - Bielčík, J. - Bielčíková, Jana - Broz, M. - Contreras, J. G. - Filová, V. - Grecká, Ekaterina - Grund, D. - Herman, T. - Isakov, Artem - Kotliarov, Artem - Krupová, D. M. - Křížek, Filip - Kushpil, Svetlana - Šafařík, K. - Torres, S. R. - Závada, Petr … Total 1041 authors
Data-driven precision determination of the material budget in ALICE.
Journal of Instrumentation. Roč. 18, č. 11 (2023), č. článku P11032. ISSN 1748-0221. E-ISSN 1748-0221
R&D Projects: GA MŠMT LM2023040
Institutional support: RVO:68378271 ; RVO:61389005
Keywords : ALICE collaboration * Analysis and statistical methods * Detector modelling and simulations * Particle tracking detectors
OECD category: Nuclear physics; Particles and field physics (FZU-D)
Impact factor: 1.3, year: 2022
Method of publishing: Open access
https://doi.org/10.1088/1748-0221/18/11/P11032

The knowledge of the material budget with a high precision is fundamental for measurements of direct photon production using the photon conversion method due to its direct impact on the total systematic uncertainty. Moreover, it influences many aspects of the charged-particle reconstruction performance. In this article, two procedures to determine data-driven corrections to the material-budget description in ALICE simulation software are developed. One is based on the precise knowledge of the gas composition in the Time Projection Chamber. The other is based on the robustness of the ratio between the produced number of photons and charged particles, to a large extent due to the approximate isospin symmetry in the number of produced neutral and charged pions. Both methods are applied to ALICE data allowing for a reduction of the overall material budget systematic uncertainty from 4.5% down to 2.5%. Using these methods, a locally correct material budget is also achieved. The two proposed methods are generic and can be applied to any experiment in a similar fashion.
Permanent Link: https://hdl.handle.net/11104/0350773