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Title: Data-driven precision determination of the material budget in ALICE
Abstract The knowledge of the material budget with a high precision is fundamental for measurements of direct photonproduction 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 theoverall material budget systematic uncertainty from 4.5% down to2.5%. Using these methods, a locally correct material budget is alsoachieved. The two proposed methods are generic and can be applied toany experiment in a similar fashion.  more » « less
Award ID(s):
2012154
PAR ID:
10554979
Author(s) / Creator(s):
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Corporate Creator(s):
Publisher / Repository:
IOP Science
Date Published:
Journal Name:
Journal of Instrumentation
Volume:
18
Issue:
11
ISSN:
1748-0221
Page Range / eLocation ID:
P11032
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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