Data-driven precision determination of the material budget in ALICE
Data-driven precision determination of the material budget in ALICE
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DOI：
10.1088/1748-0221/18/11/p11032
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发表时间：
2023-03
影响因子：
1.3
通讯作者：
S. Acharya;D. Adamová;A. Adler;G. Aglieri Rinella;M. Agnello;N. Agrawal;Z. Ahammed;S. Ahmad
中科院分区：
文献类型：
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作者：
S. Acharya;D. Adamová;A. Adler;G. Aglieri Rinella;M. Agnello;N. Agrawal;Z. Ahammed;S. Ahmad
具有高精度的材料预算的知识是使用光子转换方法测量直接光子产生的基础，因为它直接影响总的系统不确定性。此外，它影响带电粒子重建性能的许多方面。在这篇文章中，两个程序来确定数据驱动的修正ALICE模拟软件中的材料预算描述。一种是基于对时间投影室中气体成分的精确了解。另一种是基于所产生的光子和带电粒子的数量之间的比率的鲁棒性，在很大程度上是由于所产生的中性和带电π介子的数量近似的同位旋对称性。这两种方法都适用于ALICE数据允许减少整体材料预算系统的不确定性从4.5%下降到2.5%。使用这些方法，还实现了局部正确的材料预算。所提出的两种方法是通用的，可以以类似的方式应用于任何实验。
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.