A New Baseline Subtraction Method for Di-hadron Correlations in High-multiplicity Small System Collisions

Journal of the Korean Physical Society - Tập 73 - Trang 677-683 - 2018
Seyoung Han1, ShinIchi Esumi2, Kazuki Sato2, Itaru Nakagawa3,4, Takahito Todoroki4
1Department of Physics, Ewha Womans University, Seoul, Korea
2Tomonaga Center for the History of the Universe, University of Tsukuba, Tsukuba, Ibaraki 305, Japan
3RIKEN Nishina Center for Accelerator-Based Science, Wako, Saitama, Japan
4RIKEN/BNL Research Center, Brookhaven National Laboratory, Upton, USA

Tóm tắt

Azimuthal anisotropy in high-multiplicity small system collisions is often quantified by the harmonic modulations cn = ‹cos (nΔφ)› in di-hadron azimuthal correlations, with a non-flow baseline subtraction using correlation functions in low-multiplicity events. We present mathematical evaluations for three different baseline subtraction methods; i) the template fit method, ii) the reference fit method, and iii) the c1 scaling method. We describe conceptual differences among the three methods. These methods are compared and examined using a toy Monte Carlo model with various realistic cn values implemented in high-multiplicity events. Our results show the reference fit method is more stable than the template fit method because the reference fit does not estimate the flow yield. On the other hand, the template fit method can evaluate the flow effect reasonably, for the case where the flow does not contain c1 factor.

Tài liệu tham khảo

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