This repository contains material related to a subensemble acceptance method (SAM). The SAM is a procedure to evaluate the effect of exact global conservation laws on cumulants of a random number distribution in a subsystem.
The SAM was originally developed to describe cumulants of a conserved quantity measured in a subvolume of a uniform thermal system. The results were first obtained for a case of single conserved charge in
- V. Vovchenko, O. Savchuk, R. Poberezhnyuk, M.I. Gorenstein, V. Koch, Connecting fluctuation measurements in heavy-ion collisions with the grand-canonical susceptibilities, Phys. Lett. B 811, 135868 (2020) [arXiv:2003.13905 [hep-ph]]
The SAM was extended for the case of multiple conserved charges in
- V. Vovchenko, R. Poberezhnyuk, V. Koch, Cumulants of multiple conserved charges and global conservation laws, JHEP 10, 089 (2020) [arXiv:2007.03850 [hep-ph]]
- A Wolfram Mathematica notebook SAM-MultipleConservedCharges.nb allows one to express an arbitrary cumulant of conserved charges up to sixth order in terms of the grand-canonical susceptibilities and acceptance parameter α. The final expressions are written using the notation commonly employed in QCD literature.
SAM-2.0 extends the original method to non-uniform systems and arbitrary subsystems (acceptances), such as that in momentum space. This method is documented in
- V. Vovchenko, Correcting event-by-event fluctuations in heavy-ion collisions for exact global conservation laws with the generalized subensemble acceptance method, arXiv:2106.13775 [hep-ph]
- A Wolfram Mathematica notebook SAM2.0-conserved allows one to express cumulants of a conserved quantity measured in the acceptance and constrained by exact global conservation in terms of the unconstrained (''grand-canonical'') cumulants inside and outside the acceptance. Calculations proceed recursively up to arbitrary order.
- A Wolfram Mathematica notebook SAM2.0-conserved-and-nonconserved allows one to express the joint cumulants of conserved and non-conserved quantities in the acceptance and constrained by exact global conservation in terms of the unconstrained (''grand-canonical'') joint cumulants inside and outside the acceptance. Calculations proceed recursively up to arbitrary order.
Publications using either the SAM or SAM-2.0 should include references to the corresponding papers listed above.
Copyright (C) 2020-2021 Volodymyr Vovchenko